Only set chat UUID if not already set

Fixes #1310

.github/CONTRIBUTING.md

@@ -19,7 +19,7 @@ This page will detail specific things that must be done if you intend to contrib
 
 #### Ready? Let's get started!
 1. Read the [Protocol Changes](http://wiki.vg/Protocol_History). Always make sure the list is both
-complete and correct. If you're unsure, don't hesitate to ask in #mcdevs (the people who maintain wiki.vg) on [freenode.net](http://freenode.net)
+complete and correct. If you're unsure, don't hesitate to ask in #mcdevs (the people who maintain wiki.vg) on [libera.chat](http://libera.chat)
 or #spigot on [irc.spi.gt](http://irc.spi.gt) ([webchat](https://irc.spi.gt/iris/?channels=spigot)).
 2. Search for usages of the now-defunct NMS package guard and change them.
 3. The class `com.comphenix.protocol.PacketType` contains a list of all the packets. If any packets were added or removed
@@ -35,4 +35,4 @@ and the release date.
 8. `com.comphenix.protocol.utility.MinecraftProtocolVersion` contains a map of all the protocol version integers.
 If the protocol version has been incremented, add a new line to the map.
 9. `mvn` in root directory again. If it builds successfully, test on the appropriate version of a Spigot server. If
-the build fails, debug!
+the build fails, debug!

.github/workflows/build.yml

@@ -0,0 +1,26 @@
+name: ProtocolLib full build lifecycle
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup java
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'adopt'
+          java-version: '16'
+          check-latest: true
+
+      - name: Run maven build lifecycle
+        run: mvn --batch-mode clean test package
+
+      - name: Upload plugin file
+        uses: actions/upload-artifact@v2
+        with:
+            name: ProtocolLib
+            path: target/ProtocolLib.jar

.travis.yml

@@ -1,11 +0,0 @@
-language: java
-jdk:
-  - openjdk8
-script: mvn clean test
-install: true
-notifications:
-  email:
-    recipients:
-      - "dmulloy2@live.com"
-    on_success: change
-    on_failure: always

Readme.md

@@ -1,4 +1,4 @@
-# ProtocolLib [![Travis Status](https://travis-ci.org/dmulloy2/ProtocolLib.svg?branch=master)](https://travis-ci.org/dmulloy2/ProtocolLib)
+# ProtocolLib
 
 Certain tasks are impossible to perform with the standard Bukkit API, and may require
 working with and even modify Minecraft directly. A common technique is to modify incoming

jitpack.yml

@@ -0,0 +1,5 @@
+before_install:
+  - source "$HOME/.sdkman/bin/sdkman-init.sh"
+  - sdk update
+  - sdk install java 16.0.1.hs-adpt
+  - sdk use java 16.0.1.hs-adpt

pom.xml

@@ -4,7 +4,7 @@
     <groupId>com.comphenix.protocol</groupId>
 	<artifactId>ProtocolLib</artifactId>
 	<name>ProtocolLib</name>
-	<version>4.6.0</version>
+	<version>4.7.0-SNAPSHOT</version>
 
 	<description>Provides read/write access to the Minecraft protocol.</description>
 	<url>https://github.com/dmulloy2/ProtocolLib</url>
@@ -17,7 +17,7 @@
 		<project.fullVersion>${project.version}</project.fullVersion>
 
 		<powermock.version>2.0.7</powermock.version>
-		<spigot.version>1.16.4-R0.1-SNAPSHOT</spigot.version>
+		<spigot.version>1.17.1-R0.1-SNAPSHOT</spigot.version>
 	</properties>
 
 	<build>
@@ -108,6 +108,9 @@
 							<value>${project.version}</value>
 						</property>
 					</systemProperties>
+					<!-- TODO figure out a better way to do this before Java 17 -->
+					<!-- We're currently waiting on powermock, but we may need to switch -->
+					<argLine>--illegal-access=permit</argLine>
 				</configuration>
 			</plugin>
 
@@ -147,8 +150,8 @@
 			</activation>
 			<properties>
 				<project.build.number>-b${env.BUILD_NUMBER}</project.build.number>
-				<!--<project.fullVersion>${project.version}${project.build.number}</project.fullVersion>-->
-				<project.fullVersion>${project.version}</project.fullVersion>
+				<project.fullVersion>${project.version}${project.build.number}</project.fullVersion>
+				<!--<project.fullVersion>${project.version}</project.fullVersion>-->
 			</properties>
 		</profile>
 
@@ -254,18 +257,18 @@
 	<distributionManagement>
 		<repository>
 			<id>dmulloy2-releases</id>
-			<url>https://repo.dmulloy2.net/nexus/repository/releases/</url>
+			<url>https://repo.dmulloy2.net/repository/releases/</url>
 		</repository>
 		<snapshotRepository>
 			<id>dmulloy2-snapshots</id>
-			<url>https://repo.dmulloy2.net/nexus/repository/snapshots/</url>
+			<url>https://repo.dmulloy2.net/repository/snapshots/</url>
 		</snapshotRepository>
 	</distributionManagement>
 
 	<repositories>
 		<repository>
 			<id>dmulloy2-repo</id>
-			<url>https://repo.dmulloy2.net/nexus/repository/public/</url>
+			<url>https://repo.dmulloy2.net/repository/public/</url>
 		</repository>
 		<repository>
 			<id>spigot-repo</id>
@@ -293,11 +296,17 @@
 			<version>${spigot.version}</version>
 			<scope>provided</scope>
 		</dependency>
+		<dependency>
+			<groupId>net.kyori</groupId>
+			<artifactId>adventure-text-serializer-gson</artifactId>
+			<version>4.5.1</version>
+			<scope>provided</scope>
+		</dependency>
 		<!-- https://mvnrepository.com/artifact/net.bytebuddy/byte-buddy -->
 		<dependency>
 			<groupId>net.bytebuddy</groupId>
 			<artifactId>byte-buddy</artifactId>
-			<version>1.10.16</version>
+			<version>1.11.0</version>
 		</dependency>
 
 		<!-- Testing dependencies -->

src/main/java/com/comphenix/protocol/PacketType.java

@@ -11,6 +11,7 @@ import java.util.function.Consumer;
 import com.comphenix.protocol.PacketTypeLookup.ClassLookup;
 import com.comphenix.protocol.events.ConnectionSide;
 import com.comphenix.protocol.injector.packet.PacketRegistry;
+import com.comphenix.protocol.utility.Constants;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
 import com.google.common.base.Preconditions;
@@ -107,93 +108,104 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 			public static final PacketType SPAWN_ENTITY_LIVING =          new PacketType(PROTOCOL, SENDER, 0x02, "SpawnEntityLiving", "SPacketSpawnMob");
 			public static final PacketType SPAWN_ENTITY_PAINTING =        new PacketType(PROTOCOL, SENDER, 0x03, "SpawnEntityPainting", "SPacketSpawnPainting");
 			public static final PacketType NAMED_ENTITY_SPAWN =           new PacketType(PROTOCOL, SENDER, 0x04, "NamedEntitySpawn", "SPacketSpawnPlayer");
-			public static final PacketType ANIMATION =                    new PacketType(PROTOCOL, SENDER, 0x05, "Animation", "SPacketAnimation");
-			public static final PacketType STATISTIC =                    new PacketType(PROTOCOL, SENDER, 0x06, "Statistic", "SPacketStatistics");
-			public static final PacketType BLOCK_BREAK =                  new PacketType(PROTOCOL, SENDER, 0x07, "BlockBreak");
-			public static final PacketType BLOCK_BREAK_ANIMATION =        new PacketType(PROTOCOL, SENDER, 0x08, "BlockBreakAnimation", "SPacketBlockBreakAnim");
-			public static final PacketType TILE_ENTITY_DATA =             new PacketType(PROTOCOL, SENDER, 0x09, "TileEntityData", "SPacketUpdateTileEntity");
-			public static final PacketType BLOCK_ACTION =                 new PacketType(PROTOCOL, SENDER, 0x0A, "BlockAction", "SPacketBlockAction");
-			public static final PacketType BLOCK_CHANGE =                 new PacketType(PROTOCOL, SENDER, 0x0B, "BlockChange", "SPacketBlockChange");
-			public static final PacketType BOSS =                         new PacketType(PROTOCOL, SENDER, 0x0C, "Boss", "SPacketUpdateBossInfo");
-			public static final PacketType SERVER_DIFFICULTY =            new PacketType(PROTOCOL, SENDER, 0x0D, "ServerDifficulty", "SPacketServerDifficulty");
-			public static final PacketType CHAT =                         new PacketType(PROTOCOL, SENDER, 0x0E, "Chat", "SPacketChat");
-			public static final PacketType TAB_COMPLETE =                 new PacketType(PROTOCOL, SENDER, 0x0F, "TabComplete", "SPacketTabComplete");
-			public static final PacketType COMMANDS =                     new PacketType(PROTOCOL, SENDER, 0x10, "Commands");
-			public static final PacketType TRANSACTION =                  new PacketType(PROTOCOL, SENDER, 0x11, "Transaction", "SPacketConfirmTransaction");
-			public static final PacketType CLOSE_WINDOW =                 new PacketType(PROTOCOL, SENDER, 0x12, "CloseWindow", "SPacketCloseWindow");
-			public static final PacketType WINDOW_ITEMS =                 new PacketType(PROTOCOL, SENDER, 0x13, "WindowItems", "SPacketWindowItems");
-			public static final PacketType WINDOW_DATA =                  new PacketType(PROTOCOL, SENDER, 0x14, "WindowData", "SPacketWindowProperty");
-			public static final PacketType SET_SLOT =                     new PacketType(PROTOCOL, SENDER, 0x15, "SetSlot", "SPacketSetSlot");
-			public static final PacketType SET_COOLDOWN =                 new PacketType(PROTOCOL, SENDER, 0x16, "SetCooldown", "SPacketCooldown");
-			public static final PacketType CUSTOM_PAYLOAD =               new PacketType(PROTOCOL, SENDER, 0x17, "CustomPayload", "SPacketCustomPayload");
-			public static final PacketType CUSTOM_SOUND_EFFECT =          new PacketType(PROTOCOL, SENDER, 0x18, "CustomSoundEffect", "SPacketCustomSound");
-			public static final PacketType KICK_DISCONNECT =              new PacketType(PROTOCOL, SENDER, 0x19, "KickDisconnect", "SPacketDisconnect");
-			public static final PacketType ENTITY_STATUS =                new PacketType(PROTOCOL, SENDER, 0x1A, "EntityStatus", "SPacketEntityStatus");
-			public static final PacketType EXPLOSION =                    new PacketType(PROTOCOL, SENDER, 0x1B, "Explosion", "SPacketExplosion");
-			public static final PacketType UNLOAD_CHUNK =                 new PacketType(PROTOCOL, SENDER, 0x1C, "UnloadChunk", "SPacketUnloadChunk");
-			public static final PacketType GAME_STATE_CHANGE =            new PacketType(PROTOCOL, SENDER, 0x1D, "GameStateChange", "SPacketChangeGameState");
-			public static final PacketType OPEN_WINDOW_HORSE =            new PacketType(PROTOCOL, SENDER, 0x1E, "OpenWindowHorse");
-			public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x1F, "KeepAlive", "SPacketKeepAlive");
-			public static final PacketType MAP_CHUNK =                    new PacketType(PROTOCOL, SENDER, 0x20, "MapChunk", "SPacketChunkData");
-			public static final PacketType WORLD_EVENT =                  new PacketType(PROTOCOL, SENDER, 0x21, "WorldEvent", "SPacketEffect");
-			public static final PacketType WORLD_PARTICLES =              new PacketType(PROTOCOL, SENDER, 0x22, "WorldParticles", "SPacketParticles");
-			public static final PacketType LIGHT_UPDATE =                 new PacketType(PROTOCOL, SENDER, 0x23, "LightUpdate");
-			public static final PacketType LOGIN =                        new PacketType(PROTOCOL, SENDER, 0x24, "Login", "SPacketJoinGame");
-			public static final PacketType MAP =                          new PacketType(PROTOCOL, SENDER, 0x25, "Map", "SPacketMaps");
-			public static final PacketType OPEN_WINDOW_MERCHANT =         new PacketType(PROTOCOL, SENDER, 0x26, "OpenWindowMerchant");
-			public static final PacketType REL_ENTITY_MOVE =              new PacketType(PROTOCOL, SENDER, 0x27, "Entity$RelEntityMove", "SPacketEntity$S15PacketEntityRelMove");
-			public static final PacketType REL_ENTITY_MOVE_LOOK =         new PacketType(PROTOCOL, SENDER, 0x28, "Entity$RelEntityMoveLook", "SPacketEntity$S17PacketEntityLookMove");
-			public static final PacketType ENTITY_LOOK =                  new PacketType(PROTOCOL, SENDER, 0x29, "Entity$EntityLook", "SPacketEntity$S16PacketEntityLook");
-			public static final PacketType ENTITY =                       new PacketType(PROTOCOL, SENDER, 0x2A, "Entity", "SPacketEntity");
-			public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x2B, "VehicleMove", "SPacketMoveVehicle");
-			public static final PacketType OPEN_BOOK =                    new PacketType(PROTOCOL, SENDER, 0x2C, "OpenBook");
-			public static final PacketType OPEN_WINDOW =                  new PacketType(PROTOCOL, SENDER, 0x2D, "OpenWindow", "SPacketOpenWindow");
-			public static final PacketType OPEN_SIGN_EDITOR =             new PacketType(PROTOCOL, SENDER, 0x2E, "OpenSignEditor", "SPacketSignEditorOpen");
-			public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x2F, "AutoRecipe", "SPacketPlaceGhostRecipe");
-			public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x30, "Abilities", "SPacketPlayerAbilities");
-			public static final PacketType COMBAT_EVENT =                 new PacketType(PROTOCOL, SENDER, 0x31, "CombatEvent", "SPacketCombatEvent");
-			public static final PacketType PLAYER_INFO =                  new PacketType(PROTOCOL, SENDER, 0x32, "PlayerInfo", "SPacketPlayerListItem");
-			public static final PacketType LOOK_AT =                      new PacketType(PROTOCOL, SENDER, 0x33, "LookAt", "SPacketPlayerPosLook");
-			public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x34, "Position");
-			public static final PacketType RECIPES =                      new PacketType(PROTOCOL, SENDER, 0x35, "Recipes", "SPacketRecipeBook");
-			public static final PacketType ENTITY_DESTROY =               new PacketType(PROTOCOL, SENDER, 0x36, "EntityDestroy", "SPacketDestroyEntities");
-			public static final PacketType REMOVE_ENTITY_EFFECT =         new PacketType(PROTOCOL, SENDER, 0x37, "RemoveEntityEffect", "SPacketRemoveEntityEffect");
-			public static final PacketType RESOURCE_PACK_SEND =           new PacketType(PROTOCOL, SENDER, 0x38, "ResourcePackSend", "SPacketResourcePackSend");
-			public static final PacketType RESPAWN =                      new PacketType(PROTOCOL, SENDER, 0x39, "Respawn", "SPacketRespawn");
-			public static final PacketType ENTITY_HEAD_ROTATION =         new PacketType(PROTOCOL, SENDER, 0x3A, "EntityHeadRotation", "SPacketEntityHeadLook");
-			public static final PacketType MULTI_BLOCK_CHANGE =           new PacketType(PROTOCOL, SENDER, 0x3B, "MultiBlockChange", "SPacketMultiBlockChange");
-			public static final PacketType SELECT_ADVANCEMENT_TAB =       new PacketType(PROTOCOL, SENDER, 0x3C, "SelectAdvancementTab", "SPacketSelectAdvancementsTab");
-			public static final PacketType WORLD_BORDER =                 new PacketType(PROTOCOL, SENDER, 0x3D, "WorldBorder", "SPacketWorldBorder");
-			public static final PacketType CAMERA =                       new PacketType(PROTOCOL, SENDER, 0x3E, "Camera", "SPacketCamera");
-			public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x3F, "HeldItemSlot", "SPacketHeldItemChange");
-			public static final PacketType VIEW_CENTRE =                  new PacketType(PROTOCOL, SENDER, 0x40, "ViewCentre");
-			public static final PacketType VIEW_DISTANCE =                new PacketType(PROTOCOL, SENDER, 0x41, "ViewDistance");
-			public static final PacketType SPAWN_POSITION =               new PacketType(PROTOCOL, SENDER, 0x42, "SpawnPosition", "SPacketSpawnPosition");
-			public static final PacketType SCOREBOARD_DISPLAY_OBJECTIVE = new PacketType(PROTOCOL, SENDER, 0x43, "ScoreboardDisplayObjective", "SPacketDisplayObjective");
-			public static final PacketType ENTITY_METADATA =              new PacketType(PROTOCOL, SENDER, 0x44, "EntityMetadata", "SPacketEntityMetadata");
-			public static final PacketType ATTACH_ENTITY =                new PacketType(PROTOCOL, SENDER, 0x45, "AttachEntity", "SPacketEntityAttach");
-			public static final PacketType ENTITY_VELOCITY =              new PacketType(PROTOCOL, SENDER, 0x46, "EntityVelocity", "SPacketEntityVelocity");
-			public static final PacketType ENTITY_EQUIPMENT =             new PacketType(PROTOCOL, SENDER, 0x47, "EntityEquipment", "SPacketEntityEquipment");
-			public static final PacketType EXPERIENCE =                   new PacketType(PROTOCOL, SENDER, 0x48, "Experience", "SPacketSetExperience");
-			public static final PacketType UPDATE_HEALTH =                new PacketType(PROTOCOL, SENDER, 0x49, "UpdateHealth", "SPacketUpdateHealth");
-			public static final PacketType SCOREBOARD_OBJECTIVE =         new PacketType(PROTOCOL, SENDER, 0x4A, "ScoreboardObjective", "SPacketScoreboardObjective");
-			public static final PacketType MOUNT =                        new PacketType(PROTOCOL, SENDER, 0x4B, "Mount", "SPacketSetPassengers");
-			public static final PacketType SCOREBOARD_TEAM =              new PacketType(PROTOCOL, SENDER, 0x4C, "ScoreboardTeam", "SPacketTeams");
-			public static final PacketType SCOREBOARD_SCORE =             new PacketType(PROTOCOL, SENDER, 0x4D, "ScoreboardScore", "SPacketUpdateScore");
-			public static final PacketType UPDATE_TIME =                  new PacketType(PROTOCOL, SENDER, 0x4E, "UpdateTime", "SPacketTimeUpdate");
-			public static final PacketType TITLE =                        new PacketType(PROTOCOL, SENDER, 0x4F, "Title", "SPacketTitle");
-			public static final PacketType ENTITY_SOUND =                 new PacketType(PROTOCOL, SENDER, 0x50, "EntitySound", "SPacketSoundEffect");
-			public static final PacketType NAMED_SOUND_EFFECT =           new PacketType(PROTOCOL, SENDER, 0x51, "NamedSoundEffect");
-			public static final PacketType STOP_SOUND =                   new PacketType(PROTOCOL, SENDER, 0x52, "StopSound");
-			public static final PacketType PLAYER_LIST_HEADER_FOOTER =    new PacketType(PROTOCOL, SENDER, 0x53, "PlayerListHeaderFooter", "SPacketPlayerListHeaderFooter");
-			public static final PacketType NBT_QUERY =                    new PacketType(PROTOCOL, SENDER, 0x54, "NBTQuery");
-			public static final PacketType COLLECT =                      new PacketType(PROTOCOL, SENDER, 0x55, "Collect", "SPacketCollectItem");
-			public static final PacketType ENTITY_TELEPORT =              new PacketType(PROTOCOL, SENDER, 0x56, "EntityTeleport", "SPacketEntityTeleport");
-			public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x57, "Advancements", "SPacketAdvancementInfo");
-			public static final PacketType UPDATE_ATTRIBUTES =            new PacketType(PROTOCOL, SENDER, 0x58, "UpdateAttributes", "SPacketEntityProperties");
-			public static final PacketType ENTITY_EFFECT =                new PacketType(PROTOCOL, SENDER, 0x59, "EntityEffect", "SPacketEntityEffect");
-			public static final PacketType RECIPE_UPDATE =                new PacketType(PROTOCOL, SENDER, 0x5A, "RecipeUpdate");
-			public static final PacketType TAGS =                         new PacketType(PROTOCOL, SENDER, 0x5B, "Tags");
+			public static final PacketType ADD_VIBRATION_SIGNAL =         new PacketType(PROTOCOL, SENDER, 0x05, "AddVibrationSignal");
+			public static final PacketType ANIMATION =                    new PacketType(PROTOCOL, SENDER, 0x06, "Animation", "SPacketAnimation");
+			public static final PacketType STATISTIC =                    new PacketType(PROTOCOL, SENDER, 0x07, "Statistic", "SPacketStatistics");
+			public static final PacketType BLOCK_BREAK =                  new PacketType(PROTOCOL, SENDER, 0x08, "BlockBreak");
+			public static final PacketType BLOCK_BREAK_ANIMATION =        new PacketType(PROTOCOL, SENDER, 0x09, "BlockBreakAnimation", "SPacketBlockBreakAnim");
+			public static final PacketType TILE_ENTITY_DATA =             new PacketType(PROTOCOL, SENDER, 0x0A, "TileEntityData", "SPacketUpdateTileEntity");
+			public static final PacketType BLOCK_ACTION =                 new PacketType(PROTOCOL, SENDER, 0x0B, "BlockAction", "SPacketBlockAction");
+			public static final PacketType BLOCK_CHANGE =                 new PacketType(PROTOCOL, SENDER, 0x0C, "BlockChange", "SPacketBlockChange");
+			public static final PacketType BOSS =                         new PacketType(PROTOCOL, SENDER, 0x0D, "Boss", "SPacketUpdateBossInfo");
+			public static final PacketType SERVER_DIFFICULTY =            new PacketType(PROTOCOL, SENDER, 0x0E, "ServerDifficulty", "SPacketServerDifficulty");
+			public static final PacketType CHAT =                         new PacketType(PROTOCOL, SENDER, 0x0F, "Chat", "SPacketChat");
+			public static final PacketType CLEAR_TITLES =                 new PacketType(PROTOCOL, SENDER, 0x10, "ClearTitles");
+			public static final PacketType TAB_COMPLETE =                 new PacketType(PROTOCOL, SENDER, 0x11, "TabComplete", "SPacketTabComplete");
+			public static final PacketType COMMANDS =                     new PacketType(PROTOCOL, SENDER, 0x12, "Commands");
+			public static final PacketType CLOSE_WINDOW =                 new PacketType(PROTOCOL, SENDER, 0x13, "CloseWindow", "SPacketCloseWindow");
+			public static final PacketType WINDOW_ITEMS =                 new PacketType(PROTOCOL, SENDER, 0x14, "WindowItems", "SPacketWindowItems");
+			public static final PacketType WINDOW_DATA =                  new PacketType(PROTOCOL, SENDER, 0x15, "WindowData", "SPacketWindowProperty");
+			public static final PacketType SET_SLOT =                     new PacketType(PROTOCOL, SENDER, 0x16, "SetSlot", "SPacketSetSlot");
+			public static final PacketType SET_COOLDOWN =                 new PacketType(PROTOCOL, SENDER, 0x17, "SetCooldown", "SPacketCooldown");
+			public static final PacketType CUSTOM_PAYLOAD =               new PacketType(PROTOCOL, SENDER, 0x18, "CustomPayload", "SPacketCustomPayload");
+			public static final PacketType CUSTOM_SOUND_EFFECT =          new PacketType(PROTOCOL, SENDER, 0x19, "CustomSoundEffect", "SPacketCustomSound");
+			public static final PacketType KICK_DISCONNECT =              new PacketType(PROTOCOL, SENDER, 0x1A, "KickDisconnect", "SPacketDisconnect");
+			public static final PacketType ENTITY_STATUS =                new PacketType(PROTOCOL, SENDER, 0x1B, "EntityStatus", "SPacketEntityStatus");
+			public static final PacketType EXPLOSION =                    new PacketType(PROTOCOL, SENDER, 0x1C, "Explosion", "SPacketExplosion");
+			public static final PacketType UNLOAD_CHUNK =                 new PacketType(PROTOCOL, SENDER, 0x1D, "UnloadChunk", "SPacketUnloadChunk");
+			public static final PacketType GAME_STATE_CHANGE =            new PacketType(PROTOCOL, SENDER, 0x1E, "GameStateChange", "SPacketChangeGameState");
+			public static final PacketType OPEN_WINDOW_HORSE =            new PacketType(PROTOCOL, SENDER, 0x1F, "OpenWindowHorse");
+			public static final PacketType INITIALIZE_BORDER =            new PacketType(PROTOCOL, SENDER, 0x20, "InitializeBorder");
+			public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x21, "KeepAlive", "SPacketKeepAlive");
+			public static final PacketType MAP_CHUNK =                    new PacketType(PROTOCOL, SENDER, 0x22, "MapChunk", "SPacketChunkData");
+			public static final PacketType WORLD_EVENT =                  new PacketType(PROTOCOL, SENDER, 0x23, "WorldEvent", "SPacketEffect");
+			public static final PacketType WORLD_PARTICLES =              new PacketType(PROTOCOL, SENDER, 0x24, "WorldParticles", "SPacketParticles");
+			public static final PacketType LIGHT_UPDATE =                 new PacketType(PROTOCOL, SENDER, 0x25, "LightUpdate");
+			public static final PacketType LOGIN =                        new PacketType(PROTOCOL, SENDER, 0x26, "Login", "SPacketJoinGame");
+			public static final PacketType MAP =                          new PacketType(PROTOCOL, SENDER, 0x27, "Map", "SPacketMaps");
+			public static final PacketType OPEN_WINDOW_MERCHANT =         new PacketType(PROTOCOL, SENDER, 0x28, "OpenWindowMerchant");
+			public static final PacketType REL_ENTITY_MOVE =              new PacketType(PROTOCOL, SENDER, 0x29, "Entity$PacketPlayOutRelEntityMove", "Entity$RelEntityMove");
+			public static final PacketType REL_ENTITY_MOVE_LOOK =         new PacketType(PROTOCOL, SENDER, 0x2A, "Entity$PacketPlayOutRelEntityMoveLook", "Entity$RelEntityMoveLook");
+			public static final PacketType ENTITY_LOOK =                  new PacketType(PROTOCOL, SENDER, 0x2B, "Entity$PacketPlayOutEntityLook", "Entity$EntityLook");
+			public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x2C, "VehicleMove", "SPacketMoveVehicle");
+			public static final PacketType OPEN_BOOK =                    new PacketType(PROTOCOL, SENDER, 0x2D, "OpenBook");
+			public static final PacketType OPEN_WINDOW =                  new PacketType(PROTOCOL, SENDER, 0x2E, "OpenWindow", "SPacketOpenWindow");
+			public static final PacketType OPEN_SIGN_EDITOR =             new PacketType(PROTOCOL, SENDER, 0x2F, "OpenSignEditor", "SPacketSignEditorOpen");
+			public static final PacketType PING =                         new PacketType(PROTOCOL, SENDER, 0x30, "Ping");
+			public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x31, "AutoRecipe", "SPacketPlaceGhostRecipe");
+			public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x32, "Abilities", "SPacketPlayerAbilities");
+			public static final PacketType PLAYER_COMBAT_END =            new PacketType(PROTOCOL, SENDER, 0x33, "PlayerCombatEnd");
+			public static final PacketType PLAYER_COMBAT_ENTER =          new PacketType(PROTOCOL, SENDER, 0x34, "PlayerCombatEnter");
+			public static final PacketType PLAYER_COMBAT_KILL =           new PacketType(PROTOCOL, SENDER, 0x35, "PlayerCombatKill");
+			public static final PacketType PLAYER_INFO =                  new PacketType(PROTOCOL, SENDER, 0x36, "PlayerInfo", "SPacketPlayerListItem");
+			public static final PacketType LOOK_AT =                      new PacketType(PROTOCOL, SENDER, 0x37, "LookAt", "SPacketPlayerPosLook");
+			public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x38, "Position");
+			public static final PacketType RECIPES =                      new PacketType(PROTOCOL, SENDER, 0x39, "Recipes", "SPacketRecipeBook");
+			public static final PacketType ENTITY_DESTROY =               new PacketType(PROTOCOL, SENDER, 0x3A, "EntityDestroy", "SPacketDestroyEntities");
+			public static final PacketType REMOVE_ENTITY_EFFECT =         new PacketType(PROTOCOL, SENDER, 0x3B, "RemoveEntityEffect", "SPacketRemoveEntityEffect");
+			public static final PacketType RESOURCE_PACK_SEND =           new PacketType(PROTOCOL, SENDER, 0x3C, "ResourcePackSend", "SPacketResourcePackSend");
+			public static final PacketType RESPAWN =                      new PacketType(PROTOCOL, SENDER, 0x3D, "Respawn", "SPacketRespawn");
+			public static final PacketType ENTITY_HEAD_ROTATION =         new PacketType(PROTOCOL, SENDER, 0x3E, "EntityHeadRotation", "SPacketEntityHeadLook");
+			public static final PacketType MULTI_BLOCK_CHANGE =           new PacketType(PROTOCOL, SENDER, 0x3F, "MultiBlockChange", "SPacketMultiBlockChange");
+			public static final PacketType SELECT_ADVANCEMENT_TAB =       new PacketType(PROTOCOL, SENDER, 0x40, "SelectAdvancementTab", "SPacketSelectAdvancementsTab");
+			public static final PacketType SET_ACTION_BAR_TEXT =          new PacketType(PROTOCOL, SENDER, 0x41, "SetActionBarText");
+			public static final PacketType SET_BORDER_CENTER =            new PacketType(PROTOCOL, SENDER, 0x42, "SetBorderCenter");
+			public static final PacketType SET_BORDER_LERP_SIZE =         new PacketType(PROTOCOL, SENDER, 0x43, "SetBorderLerpSize");
+			public static final PacketType SET_BORDER_SIZE =              new PacketType(PROTOCOL, SENDER, 0x44, "SetBorderSize");
+			public static final PacketType SET_BORDER_WARNING_DELAY =     new PacketType(PROTOCOL, SENDER, 0x45, "SetBorderWarningDelay");
+			public static final PacketType SET_BORDER_WARNING_DISTANCE =  new PacketType(PROTOCOL, SENDER, 0x46, "SetBorderWarningDistance");
+			public static final PacketType CAMERA =                       new PacketType(PROTOCOL, SENDER, 0x47, "Camera", "SPacketCamera");
+			public static final PacketType HELD_ITEM_SLOT =               new PacketType(PROTOCOL, SENDER, 0x48, "HeldItemSlot", "SPacketHeldItemChange");
+			public static final PacketType VIEW_CENTRE =                  new PacketType(PROTOCOL, SENDER, 0x49, "ViewCentre");
+			public static final PacketType VIEW_DISTANCE =                new PacketType(PROTOCOL, SENDER, 0x4A, "ViewDistance");
+			public static final PacketType SPAWN_POSITION =               new PacketType(PROTOCOL, SENDER, 0x4B, "SpawnPosition", "SPacketSpawnPosition");
+			public static final PacketType SCOREBOARD_DISPLAY_OBJECTIVE = new PacketType(PROTOCOL, SENDER, 0x4C, "ScoreboardDisplayObjective", "SPacketDisplayObjective");
+			public static final PacketType ENTITY_METADATA =              new PacketType(PROTOCOL, SENDER, 0x4D, "EntityMetadata", "SPacketEntityMetadata");
+			public static final PacketType ATTACH_ENTITY =                new PacketType(PROTOCOL, SENDER, 0x4E, "AttachEntity", "SPacketEntityAttach");
+			public static final PacketType ENTITY_VELOCITY =              new PacketType(PROTOCOL, SENDER, 0x4F, "EntityVelocity", "SPacketEntityVelocity");
+			public static final PacketType ENTITY_EQUIPMENT =             new PacketType(PROTOCOL, SENDER, 0x50, "EntityEquipment", "SPacketEntityEquipment");
+			public static final PacketType EXPERIENCE =                   new PacketType(PROTOCOL, SENDER, 0x51, "Experience", "SPacketSetExperience");
+			public static final PacketType UPDATE_HEALTH =                new PacketType(PROTOCOL, SENDER, 0x52, "UpdateHealth", "SPacketUpdateHealth");
+			public static final PacketType SCOREBOARD_OBJECTIVE =         new PacketType(PROTOCOL, SENDER, 0x53, "ScoreboardObjective", "SPacketScoreboardObjective");
+			public static final PacketType MOUNT =                        new PacketType(PROTOCOL, SENDER, 0x54, "Mount", "SPacketSetPassengers");
+			public static final PacketType SCOREBOARD_TEAM =              new PacketType(PROTOCOL, SENDER, 0x55, "ScoreboardTeam", "SPacketTeams");
+			public static final PacketType SCOREBOARD_SCORE =             new PacketType(PROTOCOL, SENDER, 0x56, "ScoreboardScore", "SPacketUpdateScore");
+			public static final PacketType SET_SUBTITLE_TEXT =            new PacketType(PROTOCOL, SENDER, 0x57, "SetSubtitleText");
+			public static final PacketType UPDATE_TIME =                  new PacketType(PROTOCOL, SENDER, 0x58, "UpdateTime", "SPacketTimeUpdate");
+			public static final PacketType SET_TITLE_TEXT =               new PacketType(PROTOCOL, SENDER, 0x59, "SetTitleText");
+			public static final PacketType SET_TITLES_ANIMATION =         new PacketType(PROTOCOL, SENDER, 0x5A, "SetTitlesAnimation");
+			public static final PacketType ENTITY_SOUND =                 new PacketType(PROTOCOL, SENDER, 0x5B, "EntitySound", "SPacketSoundEffect");
+			public static final PacketType NAMED_SOUND_EFFECT =           new PacketType(PROTOCOL, SENDER, 0x5C, "NamedSoundEffect");
+			public static final PacketType STOP_SOUND =                   new PacketType(PROTOCOL, SENDER, 0x5D, "StopSound");
+			public static final PacketType PLAYER_LIST_HEADER_FOOTER =    new PacketType(PROTOCOL, SENDER, 0x5E, "PlayerListHeaderFooter", "SPacketPlayerListHeaderFooter");
+			public static final PacketType NBT_QUERY =                    new PacketType(PROTOCOL, SENDER, 0x5F, "NBTQuery");
+			public static final PacketType COLLECT =                      new PacketType(PROTOCOL, SENDER, 0x60, "Collect", "SPacketCollectItem");
+			public static final PacketType ENTITY_TELEPORT =              new PacketType(PROTOCOL, SENDER, 0x61, "EntityTeleport", "SPacketEntityTeleport");
+			public static final PacketType ADVANCEMENTS =                 new PacketType(PROTOCOL, SENDER, 0x62, "Advancements", "SPacketAdvancementInfo");
+			public static final PacketType UPDATE_ATTRIBUTES =            new PacketType(PROTOCOL, SENDER, 0x63, "UpdateAttributes", "SPacketEntityProperties");
+			public static final PacketType ENTITY_EFFECT =                new PacketType(PROTOCOL, SENDER, 0x64, "EntityEffect", "SPacketEntityEffect");
+			public static final PacketType RECIPE_UPDATE =                new PacketType(PROTOCOL, SENDER, 0x65, "RecipeUpdate");
+			public static final PacketType TAGS =                         new PacketType(PROTOCOL, SENDER, 0x66, "Tags");
 
 			// ---- Removed in 1.9
 
@@ -256,7 +268,7 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 			 * @deprecated Removed in 1.14
 			 */
 			@Deprecated
-			public static final PacketType BED =                          new PacketType(PROTOCOL, SENDER, 0x33, "Bed", "SPacketUseBed");
+			public static final PacketType BED =                          new PacketType(PROTOCOL, SENDER, 251, "Bed", "SPacketUseBed");
 
 			/**
 			 * @deprecated Renamed to {@link #BED}
@@ -268,7 +280,37 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 			 * @deprecated Removed in 1.16
 			 */
 			@Deprecated
-			public static final PacketType SPAWN_ENTITY_WEATHER =         new PacketType(PROTOCOL, SENDER, 0x02, "SpawnEntityWeather", "SPacketSpawnGlobalEntity");
+			public static final PacketType SPAWN_ENTITY_WEATHER =         new PacketType(PROTOCOL, SENDER, 250, "SpawnEntityWeather", "SPacketSpawnGlobalEntity");
+
+			/**
+			 * @deprecated Removed in 1.17, split into separate packets
+			 */
+			@Deprecated
+			public static final PacketType TITLE = new PacketType(PROTOCOL, SENDER, 249, "Title");
+
+			/**
+			 * @deprecated Removed in 1.17, split into separate packets
+			 */
+			@Deprecated
+			public static final PacketType WORLD_BORDER = new PacketType(PROTOCOL, SENDER, 248, "WorldBorder");
+
+			/**
+			 * @deprecated Removed in 1.17, split into separate packets
+			 */
+			@Deprecated
+			public static final PacketType COMBAT_EVENT = new PacketType(PROTOCOL, SENDER, 247, "CombatEvent");
+
+			/**
+			 * @deprecated Removed in 1.17
+			 */
+			@Deprecated
+			public static final PacketType TRANSACTION = new PacketType(PROTOCOL, SENDER, 246, "Transaction", "SPacketConfirmTransaction");
+
+			/**
+			 * @deprecated Made abstract in 1.17, no actual packet anymore
+			 */
+			@Deprecated
+			public static final PacketType ENTITY = new PacketType(PROTOCOL, SENDER, 245, "Entity", "SPacketEntity");
 
 			private final static Server INSTANCE = new Server();
 
@@ -297,29 +339,29 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 			public static final PacketType CLIENT_COMMAND =               new PacketType(PROTOCOL, SENDER, 0x04, "ClientCommand", "CPacketClientStatus");
 			public static final PacketType SETTINGS =                     new PacketType(PROTOCOL, SENDER, 0x05, "Settings", "CPacketClientSettings");
 			public static final PacketType TAB_COMPLETE =                 new PacketType(PROTOCOL, SENDER, 0x06, "TabComplete", "CPacketTabComplete");
-			public static final PacketType TRANSACTION =                  new PacketType(PROTOCOL, SENDER, 0x07, "Transaction", "CPacketConfirmTransaction");
-			public static final PacketType ENCHANT_ITEM =                 new PacketType(PROTOCOL, SENDER, 0x08, "EnchantItem", "CPacketEnchantItem");
-			public static final PacketType WINDOW_CLICK =                 new PacketType(PROTOCOL, SENDER, 0x09, "WindowClick", "CPacketClickWindow");
-			public static final PacketType CLOSE_WINDOW =                 new PacketType(PROTOCOL, SENDER, 0x0A, "CloseWindow", "CPacketCloseWindow");
-			public static final PacketType CUSTOM_PAYLOAD =               new PacketType(PROTOCOL, SENDER, 0x0B, "CustomPayload", "CPacketCustomPayload");
-			public static final PacketType B_EDIT =                       new PacketType(PROTOCOL, SENDER, 0x0C, "BEdit");
-			public static final PacketType ENTITY_NBT_QUERY =             new PacketType(PROTOCOL, SENDER, 0x0D, "EntityNBTQuery");
-			public static final PacketType USE_ENTITY =                   new PacketType(PROTOCOL, SENDER, 0x0E, "UseEntity", "CPacketUseEntity");
-			public static final PacketType JIGSAW_GENERATE =              new PacketType(PROTOCOL, SENDER, 0x0F, "JigsawGenerate");
-			public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x10, "KeepAlive", "CPacketKeepAlive");
-			public static final PacketType DIFFICULTY_LOCK =              new PacketType(PROTOCOL, SENDER, 0x11, "DifficultyLock");
-			public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x12, "Flying$Position", "CPacketPlayer$Position");
-			public static final PacketType POSITION_LOOK =                new PacketType(PROTOCOL, SENDER, 0x13, "Flying$PositionLook", "CPacketPlayer$PositionRotation");
-			public static final PacketType LOOK =                         new PacketType(PROTOCOL, SENDER, 0x14, "Flying$Look", "CPacketPlayer$Rotation");
-			public static final PacketType FLYING =                       new PacketType(PROTOCOL, SENDER, 0x15, "Flying", "CPacketPlayer");
-			public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x16, "VehicleMove", "CPacketVehicleMove");
-			public static final PacketType BOAT_MOVE =                    new PacketType(PROTOCOL, SENDER, 0x17, "BoatMove", "CPacketSteerBoat");
-			public static final PacketType PICK_ITEM =                    new PacketType(PROTOCOL, SENDER, 0x18, "PickItem");
-			public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x19, "AutoRecipe", "CPacketPlaceRecipe");
-			public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x1A, "Abilities", "CPacketPlayerAbilities");
-			public static final PacketType BLOCK_DIG =                    new PacketType(PROTOCOL, SENDER, 0x1B, "BlockDig", "CPacketPlayerDigging");
-			public static final PacketType ENTITY_ACTION =                new PacketType(PROTOCOL, SENDER, 0x1C, "EntityAction", "CPacketEntityAction");
-			public static final PacketType STEER_VEHICLE =                new PacketType(PROTOCOL, SENDER, 0x1D, "SteerVehicle", "CPacketInput");
+			public static final PacketType ENCHANT_ITEM =                 new PacketType(PROTOCOL, SENDER, 0x07, "EnchantItem", "CPacketEnchantItem");
+			public static final PacketType WINDOW_CLICK =                 new PacketType(PROTOCOL, SENDER, 0x08, "WindowClick", "CPacketClickWindow");
+			public static final PacketType CLOSE_WINDOW =                 new PacketType(PROTOCOL, SENDER, 0x09, "CloseWindow", "CPacketCloseWindow");
+			public static final PacketType CUSTOM_PAYLOAD =               new PacketType(PROTOCOL, SENDER, 0x0A, "CustomPayload", "CPacketCustomPayload");
+			public static final PacketType B_EDIT =                       new PacketType(PROTOCOL, SENDER, 0x0B, "BEdit");
+			public static final PacketType ENTITY_NBT_QUERY =             new PacketType(PROTOCOL, SENDER, 0x0C, "EntityNBTQuery");
+			public static final PacketType USE_ENTITY =                   new PacketType(PROTOCOL, SENDER, 0x0D, "UseEntity", "CPacketUseEntity");
+			public static final PacketType JIGSAW_GENERATE =              new PacketType(PROTOCOL, SENDER, 0x0E, "JigsawGenerate");
+			public static final PacketType KEEP_ALIVE =                   new PacketType(PROTOCOL, SENDER, 0x0F, "KeepAlive", "CPacketKeepAlive");
+			public static final PacketType DIFFICULTY_LOCK =              new PacketType(PROTOCOL, SENDER, 0x10, "DifficultyLock");
+			public static final PacketType POSITION =                     new PacketType(PROTOCOL, SENDER, 0x11, "Flying$PacketPlayInPosition", "Flying$Position", "CPacketPlayer$Position");
+			public static final PacketType POSITION_LOOK =                new PacketType(PROTOCOL, SENDER, 0x12, "Flying$PacketPlayInPositionLook", "Flying$PositionLook", "CPacketPlayer$PositionRotation");
+			public static final PacketType LOOK =                         new PacketType(PROTOCOL, SENDER, 0x13, "Flying$PacketPlayInLook", "Flying$Look", "CPacketPlayer$Rotation");
+			public static final PacketType GROUND =                       new PacketType(PROTOCOL, SENDER, 0x14, "Flying$d");
+			public static final PacketType VEHICLE_MOVE =                 new PacketType(PROTOCOL, SENDER, 0x15, "VehicleMove", "CPacketVehicleMove");
+			public static final PacketType BOAT_MOVE =                    new PacketType(PROTOCOL, SENDER, 0x16, "BoatMove", "CPacketSteerBoat");
+			public static final PacketType PICK_ITEM =                    new PacketType(PROTOCOL, SENDER, 0x17, "PickItem");
+			public static final PacketType AUTO_RECIPE =                  new PacketType(PROTOCOL, SENDER, 0x18, "AutoRecipe", "CPacketPlaceRecipe");
+			public static final PacketType ABILITIES =                    new PacketType(PROTOCOL, SENDER, 0x19, "Abilities", "CPacketPlayerAbilities");
+			public static final PacketType BLOCK_DIG =                    new PacketType(PROTOCOL, SENDER, 0x1A, "BlockDig", "CPacketPlayerDigging");
+			public static final PacketType ENTITY_ACTION =                new PacketType(PROTOCOL, SENDER, 0x1B, "EntityAction", "CPacketEntityAction");
+			public static final PacketType STEER_VEHICLE =                new PacketType(PROTOCOL, SENDER, 0x1C, "SteerVehicle", "CPacketInput");
+			public static final PacketType PONG =                         new PacketType(PROTOCOL, SENDER, 0x1D, "Pong", "ServerboundPongPacket");
 			public static final PacketType RECIPE_SETTINGS =              new PacketType(PROTOCOL, SENDER, 0x1E, "RecipeSettings");
 			public static final PacketType RECIPE_DISPLAYED =             new PacketType(PROTOCOL, SENDER, 0x1F, "RecipeDisplayed", "CPacketRecipeInfo");
 			public static final PacketType ITEM_NAME =                    new PacketType(PROTOCOL, SENDER, 0x20, "ItemName");
@@ -339,6 +381,18 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 			public static final PacketType USE_ITEM =                     new PacketType(PROTOCOL, SENDER, 0x2E, "UseItem", "CPacketPlayerTryUseItemOnBlock");
 			public static final PacketType BLOCK_PLACE =                  new PacketType(PROTOCOL, SENDER, 0x2F, "BlockPlace", "CPacketPlayerTryUseItem");
 
+			/**
+			 * @deprecated Removed in 1.17
+			 */
+			@Deprecated
+			public static final PacketType TRANSACTION =                  new PacketType(PROTOCOL, SENDER, 255, "Transaction", "CPacketConfirmTransaction");
+
+			/**
+			 * @deprecated Removed in 1.17
+			 */
+			@Deprecated
+			public static final PacketType FLYING = 					  new PacketType(PROTOCOL, SENDER, 254, "Flying", "CPacketPlayer");
+
 			private final static Client INSTANCE = new Client();
 
 			// Prevent accidental construction
@@ -490,15 +544,23 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 	 * @author Kristian
 	 */
 	public enum Protocol {
-		HANDSHAKING,
-		PLAY,
-		STATUS,
-		LOGIN,
+		HANDSHAKING("Handshaking", "handshake"),
+		PLAY("Play", "game"),
+		STATUS("Status", "status"),
+		LOGIN("Login", "login"),
 
 		/**
 		 * Only for packets removed in Minecraft 1.7.2
 		 */
-		LEGACY;
+		LEGACY("", "");
+
+		private String packetName;
+		private String mojangName;
+
+		Protocol(String packetName, String mojangName) {
+			this.packetName = packetName;
+			this.mojangName = mojangName;
+		}
 
 		/**
 		 * Retrieve the correct protocol enum from a given vanilla enum instance.
@@ -520,7 +582,11 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		}
 
 		public String getPacketName() {
-			return WordUtils.capitalize(name().toLowerCase(Locale.ENGLISH));
+			return packetName;
+		}
+
+		public String getMojangName() {
+			return mojangName;
 		}
 
 		public String getMcpPacketName() {
@@ -537,12 +603,22 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		/**
 		 * Indicates that packets of this type will be sent by connected clients.
 		 */
-		CLIENT,
+		CLIENT("Serverbound", "In", "client"),
 
 		/**
 		 * Indicate that packets of this type will be sent by the current server.
 		 */
-		SERVER;
+		SERVER("Clientbound", "Out", "server");
+
+		private String mojangName;
+		private String packetName;
+		private String mcpName;
+
+		Sender(String mojangName, String packetName, String mcpName) {
+			this.mojangName = mojangName;
+			this.packetName = packetName;
+			this.mcpName = mcpName;
+		}
 
 		/**
 		 * Retrieve the equivialent connection side.
@@ -553,11 +629,15 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		}
 
 		public String getPacketName() {
-			return this == CLIENT ? "In" : "Out";
+			return packetName;
 		}
 
 		public String getMcpPacketName() {
-			return name().toLowerCase(Locale.ENGLISH);
+			return mcpName;
+		}
+
+		public String getMojangName() {
+			return mojangName;
 		}
 	}
 
@@ -574,13 +654,13 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 	/**
 	 * Protocol version of all the current IDs.
 	 */
-	private static final MinecraftVersion PROTOCOL_VERSION = MinecraftVersion.NETHER_UPDATE;
+	private static final MinecraftVersion PROTOCOL_VERSION = Constants.CURRENT_VERSION;
 
 	private final Protocol protocol;
 	private final Sender sender;
 	private final int currentId;
 	private final MinecraftVersion version;
-	private final String[] classNames;
+	private final List<String> classNames;
 	String[] names;
 
 	private String name;
@@ -710,7 +790,17 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		}
 	}
 
+	private static String formatMojangClassName(Protocol protocol, Sender sender, String name) {
+		return "net.minecraft.network.protocol." + protocol.getMojangName() + "." + sender.getMojangName()
+				+ name + "Packet";
+	}
+
 	private static String formatClassName(Protocol protocol, Sender sender, String name) {
+		if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+			return "net.minecraft.network.protocol." + protocol.getMojangName() + ".Packet"
+					+ protocol.getPacketName() + sender.getPacketName() + name;
+		}
+
 		String base = MinecraftReflection.getMinecraftPackage() + ".Packet";
 		if (name.startsWith(base)) {
 			return name;
@@ -810,8 +900,8 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 
 		// Check any aliases
 		for (PacketType check : map.values()) {
-			String[] aliases = check.getClassNames();
-			if (aliases.length > 1) {
+			List<String> aliases = check.getClassNames();
+			if (aliases.size() > 1) {
 				for (String alias : aliases) {
 					if (alias.equals(clazz)) {
 						// We have a match!
@@ -852,7 +942,9 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 	 * Determine if a given class represents a packet class.
 	 * @param packetClass - the class to lookup.
 	 * @return TRUE if this is a packet class, FALSE otherwise.
+	 * @deprecated Doesn't really have a purpose
 	 */
+	@Deprecated
 	public static boolean hasClass(Class<?> packetClass) {
 		return PacketRegistry.getPacketType(packetClass) != null;
 	}
@@ -931,12 +1023,13 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		this.currentId = currentId;
 		this.version = version;
 		
-		this.classNames = new String[names.length];
-		for (int i = 0; i < classNames.length; i++) {
+		this.classNames = new ArrayList<>();
+		for (int i = 0; i < names.length; i++) {
 			if (isMcpPacketName(names[i])) { // Minecraft MCP packets
-				classNames[i] = formatMcpClassName(protocol, sender, names[i]);
+				classNames.add(formatMcpClassName(protocol, sender, names[i]));
 			} else {
-				classNames[i] = formatClassName(protocol, sender, names[i]);
+				classNames.add(formatClassName(protocol, sender, names[i]));
+				classNames.add(formatMojangClassName(protocol, sender, names[i]));
 			}
 		}
 
@@ -997,7 +1090,7 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		return currentId;
 	}
 
-	public String[] getClassNames() {
+	public List<String> getClassNames() {
 		return classNames;
 	}
 
@@ -1006,11 +1099,7 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 	 * @return The packet class, or NULL if not found.
 	 */
 	public Class<?> getPacketClass() {
-		try {
-			return PacketRegistry.getPacketClassFromType(this);
-		} catch (Exception e) {
-			return null;
-		}
+		return PacketRegistry.tryGetPacketClass(this).orElse(null);
 	}
 
 	// Only used by Enum processor
@@ -1112,7 +1201,7 @@ public class PacketType implements Serializable, Cloneable, Comparable<PacketTyp
 		Class<?> clazz = getPacketClass();
 
 		if (clazz == null)
-			return name() + "[" + protocol + ", " + sender + ", " + currentId + ", classNames: " + Arrays.toString(classNames) + " (unregistered)]";
+			return name() + "[" + protocol + ", " + sender + ", " + currentId + ", classNames: " + classNames + " (unregistered)]";
 		else
 			return name() + "[class=" + clazz.getSimpleName() + ", id=" + currentId + "]";
 	}

src/main/java/com/comphenix/protocol/PacketTypeEnum.java

@@ -110,22 +110,6 @@ public class PacketTypeEnum implements Iterable<PacketType> {
 	public boolean hasMember(PacketType member) {
 		return members.contains(member);
 	}
-	
-	/**
-	 * Retrieve a member by name,
-	 * @param name - name of member to retrieve.
-	 * @return The member, or NULL if not found.
-	 * @deprecated Don't use this
-	 */
-	@Deprecated
-	public PacketType valueOf(String name) {
-		for (PacketType member : members) {
-			if (member.name().equals(name))
-				return member;
-		}
-
-		return null;
-	}
 
 	/**
 	 * Retrieve every registered member.

src/main/java/com/comphenix/protocol/PacketTypeLookup.java

@@ -108,7 +108,7 @@ class PacketTypeLookup {
 			// Skip unknown current packets
 			if (type.getCurrentId() != PacketType.UNKNOWN_PACKET) {
 				idLookup.getMap(type.getProtocol(), type.getSender()).put(type.getCurrentId(), type);
-				classLookup.getMap(type.getProtocol(), type.getSender()).put(type.getClassNames()[0], type);
+				classLookup.getMap(type.getProtocol(), type.getSender()).put(type.getClassNames().get(0), type);
 			}
 			nameLookup.put(type.name(), type);
 		}

src/main/java/com/comphenix/protocol/ProtocolLib.java

@@ -38,6 +38,7 @@ import com.comphenix.protocol.updater.Updater;
 import com.comphenix.protocol.updater.Updater.UpdateType;
 import com.comphenix.protocol.utility.ChatExtensions;
 import com.comphenix.protocol.utility.ByteBuddyFactory;
+import com.comphenix.protocol.utility.NettyVersion;
 import com.comphenix.protocol.utility.MinecraftVersion;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Iterables;
@@ -170,7 +171,11 @@ public class ProtocolLib extends JavaPlugin {
 		// Print the state of the debug mode
 		if (config.isDebug()) {
 			logger.warning("Debug mode is enabled!");
+						logger.info("Detected netty version: " + NettyVersion.getVersion());
+		} else {
+			NettyVersion.getVersion(); // this will cache the version
 		}
+		
 		// And the state of the error reporter
 		if (config.isDetailedErrorReporting()) {
 			detailedReporter.setDetailedReporting(true);

src/main/java/com/comphenix/protocol/ProtocolLibrary.java

@@ -38,12 +38,12 @@ public class ProtocolLibrary {
 	/**
 	 * The maximum version ProtocolLib has been tested with.
 	 */
-	public static final String MAXIMUM_MINECRAFT_VERSION = "1.16.5";
+	public static final String MAXIMUM_MINECRAFT_VERSION = "1.17.1";
 
 	/**
-	 * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (1.16.5) was released.
+	 * The date (with ISO 8601 or YYYY-MM-DD) when the most recent version (1.17.1) was released.
 	 */
-	public static final String MINECRAFT_LAST_RELEASE_DATE = "2021-01-15";
+	public static final String MINECRAFT_LAST_RELEASE_DATE = "2021-07-06";
 
 	/**
 	 * Plugins that are currently incompatible with ProtocolLib.

src/main/java/com/comphenix/protocol/ProtocolLogger.java

@@ -20,6 +20,7 @@ import java.text.MessageFormat;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import com.comphenix.protocol.utility.MinecraftVersion;
 import org.bukkit.plugin.Plugin;
 
 /**
@@ -82,4 +83,10 @@ public class ProtocolLogger {
 			logger.log(Level.WARNING, "[Debug] " + message, ex);
 		}
 	}
+
+	public static void warnAbove(MinecraftVersion version, String message, Object... args) {
+		if (version.atOrAbove()) {
+			log(Level.WARNING, message, args);
+		}
+	}
 }

src/main/java/com/comphenix/protocol/concurrency/PacketTypeSet.java

@@ -32,11 +32,11 @@ public class PacketTypeSet {
 	 * @param type - the type to add.
 	 */
 	public synchronized void addType(PacketType type) {
-		Class<?> packetClass = getPacketClass(type);
+		Class<?> packetClass = type.getPacketClass();
 		types.add(Preconditions.checkNotNull(type, "type cannot be NULL."));
 		
 		if (packetClass != null) {
-			classes.add(getPacketClass(type));
+			classes.add(type.getPacketClass());
 		}
 	}
 	
@@ -55,11 +55,11 @@ public class PacketTypeSet {
 	 * @param type - the type to remove.
 	 */
 	public synchronized void removeType(PacketType type) {
-		Class<?> packetClass = getPacketClass(type);
+		Class<?> packetClass = type.getPacketClass();
 		types.remove(Preconditions.checkNotNull(type, "type cannot be NULL."));
 		
 		if (packetClass != null) {
-			classes.remove(getPacketClass(type));
+			classes.remove(packetClass);
 		}
 	}
 	
@@ -72,16 +72,7 @@ public class PacketTypeSet {
 			removeType(type);
 		}
 	}
-	
-	/**
-	 * Retrieve the packet class associated with a particular type.
-	 * @param type - the packet type.
-	 * @return The associated packet type.
-	 */
-	protected Class<?> getPacketClass(PacketType type) {
-		return PacketRegistry.getPacketClassFromType(type);
-	}
-	
+
 	/**
 	 * Determine if the given packet type exists in the set.
 	 * @param type - the type to find.

src/main/java/com/comphenix/protocol/events/InternalStructure.java

@@ -0,0 +1,45 @@
+package com.comphenix.protocol.events;
+
+import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.wrappers.Converters;
+
+import java.util.List;
+import java.util.Optional;
+
+public class InternalStructure extends AbstractStructure {
+
+    protected InternalStructure(Object handle, StructureModifier<Object> structureModifier) {
+        super(handle, structureModifier);
+    }
+
+    protected static final EquivalentConverter<InternalStructure> CONVERTER = new EquivalentConverter<InternalStructure>() {
+        @Override
+        public Object getGeneric(InternalStructure specific) {
+            return specific.handle;
+        }
+
+        @Override
+        public InternalStructure getSpecific(Object generic) {
+            return new InternalStructure(generic, new StructureModifier<>(generic.getClass()).withTarget(generic));
+        }
+
+        @Override
+        public Class<InternalStructure> getSpecificType() {
+            return InternalStructure.class;
+        }
+    };
+
+    public StructureModifier<InternalStructure> getStructures() {
+        return structureModifier.withType(Object.class, CONVERTER);
+    }
+
+    public StructureModifier<Optional<InternalStructure>> getOptionalStructures() {
+        return structureModifier.withType(Optional.class, Converters.optional(CONVERTER));
+    }
+
+    @Override
+    public String toString() {
+        return "InternalStructure[handle=" + handle + " (" + handle.getClass().getSimpleName() + ")]";
+    }
+}

src/main/java/com/comphenix/protocol/injector/EntityUtilities.java

@@ -17,6 +17,7 @@
 
 package com.comphenix.protocol.injector;
 
+import java.lang.reflect.Modifier;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -139,7 +140,7 @@ class EntityUtilities {
 	@SuppressWarnings("unchecked")
 	private Object getNewEntityTracker(Object worldServer, int entityId) {
 		if (getChunkProvider == null) {
-			Class<?> chunkProviderClass = MinecraftReflection.getMinecraftClass("ChunkProviderServer");
+			Class<?> chunkProviderClass = MinecraftReflection.getChunkProviderServer();
 			getChunkProvider = Accessors.getMethodAccessor(
 					FuzzyReflection.fromClass(worldServer.getClass(), false).getMethod(
 							FuzzyMethodContract.newBuilder().parameterCount(0).returnTypeExact(chunkProviderClass).build()));
@@ -148,7 +149,7 @@ class EntityUtilities {
 		Object chunkProvider = getChunkProvider.invoke(worldServer);
 
 		if (chunkMapField == null) {
-			Class<?> chunkMapClass = MinecraftReflection.getMinecraftClass("PlayerChunkMap");
+			Class<?> chunkMapClass = MinecraftReflection.getPlayerChunkMap();
 			chunkMapField = Accessors.getFieldAccessor(
 					FuzzyReflection.fromClass(chunkProvider.getClass(), false).getField(
 							FuzzyFieldContract.newBuilder().typeExact(chunkMapClass).build()));
@@ -157,9 +158,21 @@ class EntityUtilities {
 		Object playerChunkMap = chunkMapField.get(chunkProvider);
 
 		if (trackedEntitiesField == null) {
-			trackedEntitiesField = Accessors.getFieldAccessor(
+			if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+				trackedEntitiesField = Accessors.getFieldAccessor(
+					FuzzyReflection.fromClass(playerChunkMap.getClass(), true).getField(
+						FuzzyFieldContract.newBuilder()
+							.banModifier(Modifier.STATIC)
+							.requirePublic()
+							.typeExact(MinecraftReflection.getInt2ObjectMapClass())
+							.build()
+					)
+				);
+			} else {
+				trackedEntitiesField = Accessors.getFieldAccessor(
 					FuzzyReflection.fromClass(playerChunkMap.getClass(), false).getField(
 							FuzzyFieldContract.newBuilder().typeDerivedOf(Map.class).nameExact("trackedEntities").build()));
+			}
 		}
 
 		Map<Integer, Object> trackedEntities = (Map<Integer, Object>) trackedEntitiesField.get(playerChunkMap);
@@ -229,14 +242,17 @@ class EntityUtilities {
 			Object tracker = null;
 
 			if (trackerEntry != null) {
-				// plugins like citizens will use their own tracker
+				// plugins like citizens will use their own tracker class, so cache the result
 				FieldAccessor trackerField = trackerFields.computeIfAbsent(trackerEntry.getClass(), x -> {
+					// get the first entity field
 					try {
-						return Accessors.getFieldAccessor(trackerEntry.getClass(), "tracker", true);
-					} catch (Exception e) {
-						// Assume it's the first entity field then
-						return Accessors.getFieldAccessor(FuzzyReflection.fromObject(trackerEntry, true)
-								.getFieldByType("tracker", MinecraftReflection.getEntityClass()));
+						return Accessors.getFieldAccessor(FuzzyReflection.fromClass(trackerEntry.getClass(), true)
+								.getField(FuzzyFieldContract.newBuilder().typeExact(MinecraftReflection.getEntityClass()).build()));
+					} catch (Exception ex) {
+						// try with the default class
+						Class<?> trackerEntryClass = MinecraftReflection.getEntityTrackerClass();
+						return Accessors.getFieldAccessor(FuzzyReflection.fromClass(trackerEntryClass, true)
+								.getField(FuzzyFieldContract.newBuilder().typeExact(MinecraftReflection.getEntityClass()).build()));
 					}
 				});
 

src/main/java/com/comphenix/protocol/injector/ListenerInvoker.java

@@ -39,14 +39,6 @@ public interface ListenerInvoker {
 	 */
 	void invokePacketSending(PacketEvent event);
 
-	/**
-	 * Retrieve the associated ID of a packet.
-	 * @param packet - the packet.
-	 * @return The packet ID.
-	 */
-	@Deprecated
-	int getPacketID(Object packet);
-
 	/**
 	 * Retrieve the associated type of a packet.
 	 * @param packet - the packet.

src/main/java/com/comphenix/protocol/injector/PacketConstructor.java

@@ -20,6 +20,7 @@ package com.comphenix.protocol.injector;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.List;
+import java.util.Optional;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.error.RethrowErrorReporter;
@@ -146,13 +147,11 @@ public class PacketConstructor {
 				types[i] = Object.class;
 			}
 		}
-		Class<?> packetType = PacketRegistry.getPacketClassFromType(type, true);
-		
-		if (packetType == null)
-			throw new IllegalArgumentException("Could not find a packet by the type " + type);
-		
+
+		Class<?> packetClass = PacketRegistry.getPacketClassFromType(type);
+
 		// Find the correct constructor
-		for (Constructor<?> constructor : packetType.getConstructors()) {
+		for (Constructor<?> constructor : packetClass.getConstructors()) {
 			Class<?>[] params = constructor.getParameterTypes();
 
 			if (isCompatible(types, params)) {

src/main/java/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -979,12 +979,6 @@ public final class PacketFilterManager implements ListenerInvoker, InternalManag
 		return phaseLoginCount.get();
 	}
 
-	@Override
-	@Deprecated
-	public int getPacketID(Object packet) {
-		return PacketRegistry.getPacketID(packet.getClass());
-	}
-
 	@Override
 	public PacketType getPacketType(Object packet) {
 		if (packet == null)

src/main/java/com/comphenix/protocol/injector/StructureCache.java

@@ -19,17 +19,29 @@ package com.comphenix.protocol.injector;
 
 import java.util.HashSet;
 import java.util.Set;
+import java.util.function.Supplier;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.injector.packet.PacketRegistry;
+import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.compiler.BackgroundCompiler;
-import com.comphenix.protocol.reflect.compiler.CompileListener;
 import com.comphenix.protocol.reflect.compiler.CompiledStructureModifier;
 import com.comphenix.protocol.reflect.instances.DefaultInstances;
+import com.comphenix.protocol.utility.ByteBuddyFactory;
+import com.comphenix.protocol.utility.MinecraftMethods;
 import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.ZeroBuffer;
+
+import io.netty.buffer.ByteBuf;
+import com.google.common.base.Preconditions;
+
+import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
+import net.bytebuddy.implementation.FixedValue;
+import net.bytebuddy.matcher.ElementMatchers;
 
 /**
  * Caches structure modifiers.
@@ -37,9 +49,42 @@ import com.comphenix.protocol.utility.MinecraftReflection;
  */
 public class StructureCache {
 	// Structure modifiers
-	private static ConcurrentMap<PacketType, StructureModifier<Object>> structureModifiers = new ConcurrentHashMap<>();
+	private static final ConcurrentMap<PacketType, StructureModifier<Object>> structureModifiers = new ConcurrentHashMap<>();
+	// invocation cache for packets
+	private static final ConcurrentMap<Class<?>, Supplier<Object>> PACKET_INSTANCE_CREATORS = new ConcurrentHashMap<>();
+	// packet data serializer which always returns an empty nbt tag compound
+	private static boolean trickTried;
+	private static ConstructorAccessor TRICKED_DATA_SERIALIZER;
 
-	private static Set<PacketType> compiling = new HashSet<>();
+	private static final Set<PacketType> compiling = new HashSet<>();
+
+	public static Object newPacket(Class<?> clazz) {
+		Object result = DefaultInstances.DEFAULT.create(clazz);
+
+		if (result == null) {
+			return PACKET_INSTANCE_CREATORS.computeIfAbsent(clazz, $ -> {
+				ConstructorAccessor accessor = Accessors.getConstructorAccessorOrNull(clazz, MinecraftReflection.getPacketDataSerializerClass());
+				if (accessor != null) {
+					return () -> {
+						try {
+							return accessor.invoke(MinecraftReflection.getPacketDataSerializer(new ZeroBuffer()));
+						} catch (Exception exception) {
+							// try trick nms around as they want a non-null compound in the map_chunk packet constructor
+							ConstructorAccessor trickyDataSerializerAccessor = getTrickDataSerializerOrNull();
+							if (trickyDataSerializerAccessor != null) {
+								return accessor.invoke(trickyDataSerializerAccessor.invoke(new ZeroBuffer()));
+							}
+							// the tricks are over
+							throw new IllegalArgumentException("Unable to create packet " + clazz, exception);
+						}
+					};
+				}
+				throw new IllegalArgumentException("No matching constructor to create packet in class " + clazz);
+			}).get();
+		}
+
+		return result;
+	}
 
 	/**
 	 * Creates an empty Minecraft packet of the given type.
@@ -47,20 +92,7 @@ public class StructureCache {
 	 * @return Created packet.
 	 */
 	public static Object newPacket(PacketType type) {
-		Class<?> clazz = PacketRegistry.getPacketClassFromType(type, true);
-
-		// Check the return value
-		if (clazz != null) {
-			// TODO: Optimize DefaultInstances
-			Object result = DefaultInstances.DEFAULT.create(clazz);
-
-			if (result == null) {
-				throw new IllegalArgumentException("Failed to create packet for type: " + type);
-			}
-
-			return result;
-		}
-		throw new IllegalArgumentException("Cannot find associated packet class: " + type);
+		return newPacket(PacketRegistry.getPacketClassFromType(type));
 	}
 
 	/**
@@ -91,7 +123,9 @@ public class StructureCache {
 	 */
 	public static StructureModifier<Object> getStructure(Class<?> packetType, boolean compile) {
 		// Get the ID from the class
-		return getStructure(PacketRegistry.getPacketType(packetType), compile);
+		PacketType type = PacketRegistry.getPacketType(packetType);
+		Preconditions.checkNotNull(type, "No packet type associated with " + packetType);
+		return getStructure(type, compile);
 	}
 
 	/**
@@ -101,13 +135,14 @@ public class StructureCache {
 	 * @return A structure modifier.
 	 */
 	public static StructureModifier<Object> getStructure(final PacketType type, boolean compile) {
+		Preconditions.checkNotNull(type, "type cannot be null");
 		StructureModifier<Object> result = structureModifiers.get(type);
 
 		// We don't want to create this for every lookup
 		if (result == null) {
 			// Use the vanilla class definition
-			final StructureModifier<Object> value = new StructureModifier<Object>(
-					PacketRegistry.getPacketClassFromType(type, true), MinecraftReflection.getPacketClass(), true);
+			final StructureModifier<Object> value = new StructureModifier<>(
+					PacketRegistry.getPacketClassFromType(type), MinecraftReflection.getPacketClass(), true);
 
 			result = structureModifiers.putIfAbsent(type, value);
 
@@ -124,16 +159,42 @@ public class StructureCache {
 				final BackgroundCompiler compiler = BackgroundCompiler.getInstance();
 
 				if (!compiling.contains(type) && compiler != null) {
-					compiler.scheduleCompilation(result, new CompileListener<Object>() {
-						@Override
-						public void onCompiled(StructureModifier<Object> compiledModifier) {
-							structureModifiers.put(type, compiledModifier);
-						}
-					});
+					compiler.scheduleCompilation(result,
+							compiledModifier -> structureModifiers.put(type, compiledModifier));
 					compiling.add(type);
 				}
 			}
 		}
 		return result;
 	}
+
+	/**
+	 * Creates a packet data serializer sub-class if needed to allow the fixed read of a NbtTagCompound because of a null
+	 * check in the MapChunk packet constructor.
+	 * @return an accessor to a constructor which creates a data serializer.
+	 */
+	private static ConstructorAccessor getTrickDataSerializerOrNull() {
+		if (TRICKED_DATA_SERIALIZER == null && !trickTried) {
+			// ensure that we only try once to create the class
+			trickTried = true;
+			try {
+				// create an empty instance of a nbt tag compound that we can re-use when needed
+				Object compound = Accessors.getConstructorAccessor(MinecraftReflection.getNBTCompoundClass()).invoke();
+				// create the method in the class to read an empty nbt tag compound (currently used for MAP_CHUNK because of null check)
+				Class<?> generatedClass = ByteBuddyFactory.getInstance()
+						.createSubclass(MinecraftReflection.getPacketDataSerializerClass())
+						.name(MinecraftMethods.class.getPackage().getName() + ".ProtocolLibTricksNmsDataSerializer")
+						.method(ElementMatchers.returns(MinecraftReflection.getNBTCompoundClass())
+								.and(ElementMatchers.takesArguments(MinecraftReflection.getNBTReadLimiterClass())))
+						.intercept(FixedValue.value(compound))
+						.make()
+						.load(ByteBuddyFactory.getInstance().getClassLoader(), ClassLoadingStrategy.Default.INJECTION)
+						.getLoaded();
+				TRICKED_DATA_SERIALIZER = Accessors.getConstructorAccessor(generatedClass, ByteBuf.class);
+			} catch (Exception ignored) {
+				// can happen if unsupported
+			}
+		}
+		return TRICKED_DATA_SERIALIZER;
+	}
 }

src/main/java/com/comphenix/protocol/injector/netty/ChannelInjector.java

@@ -44,7 +44,6 @@ import com.google.common.base.Preconditions;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.*;
-import io.netty.channel.socket.SocketChannel;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.MessageToByteEncoder;
 import io.netty.util.AttributeKey;
@@ -951,7 +950,7 @@ public class ChannelInjector extends ByteToMessageDecoder implements Injector {
 
 		@Override
 		public Socket getSocket() {
-			return SocketAdapter.adapt((SocketChannel) injector.originalChannel);
+			return SocketAdapter.adapt(injector.originalChannel);
 		}
 
 		@Override
@@ -989,6 +988,11 @@ public class ChannelInjector extends ByteToMessageDecoder implements Injector {
 			injector.setPlayer(updatedPlayer);
 		}
 
+		@Override
+		public boolean isConnected() {
+			return injector.originalChannel.isActive();
+		}
+
 		ChannelInjector getChannelInjector() {
 			return injector;
 		}

src/main/java/com/comphenix/protocol/injector/netty/NettyProtocolRegistry.java

@@ -1,222 +0,0 @@
-/**
- *  ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
- *  Copyright (C) 2015 dmulloy2
- *
- *  This program is free software; you can redistribute it and/or modify it under the terms of the
- *  GNU General Public License as published by the Free Software Foundation; either version 2 of
- *  the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *  See the GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License along with this program;
- *  if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- *  02111-1307 USA
- */
-package com.comphenix.protocol.injector.netty;
-
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Map.Entry;
-
-import com.comphenix.protocol.PacketType;
-import com.comphenix.protocol.PacketType.Protocol;
-import com.comphenix.protocol.PacketType.Sender;
-import com.comphenix.protocol.ProtocolLogger;
-import com.comphenix.protocol.injector.packet.MapContainer;
-import com.comphenix.protocol.reflect.FuzzyReflection;
-import com.comphenix.protocol.reflect.StructureModifier;
-import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
-import com.comphenix.protocol.utility.MinecraftVersion;
-import com.google.common.collect.Maps;
-
-/**
- * @author dmulloy2
- */
-
-public class NettyProtocolRegistry extends ProtocolRegistry {
-
-	public NettyProtocolRegistry() {
-		super();
-	}
-
-	@Override
-	protected synchronized void initialize() {
-		if (MinecraftVersion.getCurrentVersion().isAtLeast(MinecraftVersion.BEE_UPDATE)) {
-			initializeNew();
-			return;
-		}
-
-		Object[] protocols = enumProtocol.getEnumConstants();
-
-		// ID to Packet class maps
-		Map<Object, Map<Integer, Class<?>>> serverMaps = Maps.newLinkedHashMap();
-		Map<Object, Map<Integer, Class<?>>> clientMaps = Maps.newLinkedHashMap();
-
-		Register result = new Register();
-		StructureModifier<Object> modifier = null;
-
-		// Iterate through the protocols
-		for (Object protocol : protocols) {
-			if (modifier == null) {
-				modifier = new StructureModifier<Object>(protocol.getClass().getSuperclass(), false);
-			}
-
-			StructureModifier<Map<Object, Map<Integer, Class<?>>>> maps = modifier.withTarget(protocol).withType(Map.class);
-			for (Entry<Object, Map<Integer, Class<?>>> entry : maps.read(0).entrySet()) {
-				String direction = entry.getKey().toString();
-				if (direction.contains("CLIENTBOUND")) { // Sent by Server
-					serverMaps.put(protocol, entry.getValue());
-				} else if (direction.contains("SERVERBOUND")) { // Sent by Client
-					clientMaps.put(protocol, entry.getValue());
-				}
-			}
-		}
-
-		// Maps we have to occasionally check have changed
-		for (Object map : serverMaps.values()) {
-			result.containers.add(new MapContainer(map));
-		}
-
-		for (Object map : clientMaps.values()) {
-			result.containers.add(new MapContainer(map));
-		}
-
-		for (Object protocol : protocols) {
-			Enum<?> enumProtocol = (Enum<?>) protocol;
-			Protocol equivalent = Protocol.fromVanilla(enumProtocol);
-			
-			// Associate known types
-			if (serverMaps.containsKey(protocol))
-				associatePackets(result, serverMaps.get(protocol), equivalent, Sender.SERVER);
-			if (clientMaps.containsKey(protocol))
-				associatePackets(result, clientMaps.get(protocol), equivalent, Sender.CLIENT);
-		}
-
-		// Exchange (thread safe, as we have only one writer)
-		this.register = result;
-	}
-
-	@SuppressWarnings("unchecked")
-	private synchronized void initializeNew() {
-		Object[] protocols = enumProtocol.getEnumConstants();
-
-		// ID to Packet class maps
-		Map<Object, Map<Class<?>, Integer>> serverMaps = Maps.newLinkedHashMap();
-		Map<Object, Map<Class<?>, Integer>> clientMaps = Maps.newLinkedHashMap();
-
-		Register result = new Register();
-		Field mainMapField = null;
-		Field packetMapField = null;
-
-		// Iterate through the protocols
-		for (Object protocol : protocols) {
-			if (mainMapField == null) {
-				FuzzyReflection fuzzy = FuzzyReflection.fromClass(protocol.getClass(), true);
-				mainMapField = fuzzy.getField(FuzzyFieldContract.newBuilder()
-						.banModifier(Modifier.STATIC)
-						.requireModifier(Modifier.FINAL)
-						.typeDerivedOf(Map.class)
-						.build());
-				mainMapField.setAccessible(true);
-			}
-
-			Map<Object, Object> directionMap;
-
-			try {
-				directionMap = (Map<Object, Object>) mainMapField.get(protocol);
-			} catch (ReflectiveOperationException ex) {
-				throw new RuntimeException("Failed to access packet map", ex);
-			}
-
-			for (Entry<Object, Object> entry : directionMap.entrySet()) {
-				Object holder = entry.getValue();
-				if (packetMapField == null) {
-					FuzzyReflection fuzzy = FuzzyReflection.fromClass(holder.getClass(), true);
-					packetMapField = fuzzy.getField(FuzzyFieldContract.newBuilder()
-							.banModifier(Modifier.STATIC)
-							.requireModifier(Modifier.FINAL)
-							.typeDerivedOf(Map.class)
-							.build());
-					packetMapField.setAccessible(true);
-				}
-
-				Map<Class<?>, Integer> packetMap;
-
-				try {
-					packetMap = (Map<Class<?>, Integer>) packetMapField.get(holder);
-				} catch (ReflectiveOperationException ex) {
-					throw new RuntimeException("Failed to access packet map", ex);
-				}
-
-				String direction = entry.getKey().toString();
-				if (direction.contains("CLIENTBOUND")) { // Sent by Server
-					serverMaps.put(protocol, packetMap);
-				} else if (direction.contains("SERVERBOUND")) { // Sent by Client
-					clientMaps.put(protocol, packetMap);
-				}
-			}
-		}
-
-		// Maps we have to occasionally check have changed
-		// TODO: Find equivalent in Object2IntMap
-
-		/* for (Object map : serverMaps.values()) {
-			result.containers.add(new MapContainer(map));
-		}
-
-		for (Object map : clientMaps.values()) {
-			result.containers.add(new MapContainer(map));
-		} */
-
-		for (Object protocol : protocols) {
-			Enum<?> enumProtocol = (Enum<?>) protocol;
-			Protocol equivalent = Protocol.fromVanilla(enumProtocol);
-
-			// Associate known types
-			if (serverMaps.containsKey(protocol)) {
-				associatePackets(result, reverse(serverMaps.get(protocol)), equivalent, Sender.SERVER);
-			}
-			if (clientMaps.containsKey(protocol)) {
-				associatePackets(result, reverse(clientMaps.get(protocol)), equivalent, Sender.CLIENT);
-			}
-		}
-
-		// Exchange (thread safe, as we have only one writer)
-		this.register = result;
-	}
-
-	/**
-	 * Reverses a key->value map to value->key
-	 * Non-deterministic behavior when multiple keys are mapped to the same value
-	 */
-	private <K, V> Map<V, K> reverse(Map<K, V> map) {
-		Map<V, K> newMap = new HashMap<>(map.size());
-		for (Entry<K, V> entry : map.entrySet()) {
-			newMap.put(entry.getValue(), entry.getKey());
-		}
-		return newMap;
-	}
-
-	@Override
-	protected void associatePackets(Register register, Map<Integer, Class<?>> lookup, Protocol protocol, Sender sender) {
-		for (Entry<Integer, Class<?>> entry : lookup.entrySet()) {
-			PacketType type = PacketType.fromCurrent(protocol, sender, entry.getKey(), entry.getValue());
-			// System.out.println(Arrays.toString(type.getClassNames()) + " -> " + entry.getValue());
-
-			try {
-				register.typeToClass.put(type, entry.getValue());
-
-				if (sender == Sender.SERVER)
-					register.serverPackets.add(type);
-				if (sender == Sender.CLIENT)
-					register.clientPackets.add(type);
-			} catch (Exception ex) {
-				ProtocolLogger.debug("Encountered an exception associating packet " + type, ex);
-			}
-		}
-	}
-}

src/main/java/com/comphenix/protocol/injector/netty/ProtocolInjector.java

@@ -46,6 +46,7 @@ import com.comphenix.protocol.injector.player.PlayerInjectionHandler;
 import com.comphenix.protocol.injector.server.TemporaryPlayerFactory;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.VolatileField;
+import com.comphenix.protocol.utility.NettyVersion;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
 import com.google.common.collect.Lists;
@@ -146,10 +147,15 @@ public class ProtocolInjector implements ChannelListener {
 				protected void initChannel(final Channel channel) throws Exception {
 					try {
 						synchronized (networkManagers) {
-							// For some reason it needs to be delayed on 1.12, but the delay breaks 1.11 and below
+							// For some reason it needs to be delayed when using netty 4.1.24 (minecraft  1.12) or newer,
+							// but the delay breaks older minecraft versions
 							// TODO I see this more as a temporary hotfix than a permanent solution
-							if (MinecraftVersion.getCurrentVersion().getMinor() >= 12) {
-								channel.eventLoop().submit(() ->
+
+							// Check if the netty version is greater than 4.1.24, that's the version bundled with spigot 1.12
+							NettyVersion ver = NettyVersion.getVersion();
+							if ((ver.isValid() && ver.isGreaterThan(4,1,24)) ||
+									MinecraftVersion.getCurrentVersion().getMinor() >= 12) { // fallback if netty version couldn't be detected
+							channel.eventLoop().submit(() ->
 									injectionFactory.fromChannel(channel, ProtocolInjector.this, playerFactory).inject());
 							} else {
 								injectionFactory.fromChannel(channel, ProtocolInjector.this, playerFactory).inject();
@@ -180,6 +186,12 @@ public class ProtocolInjector implements ChannelListener {
 					channel.pipeline().addFirst(beginInitProtocol);
 					ctx.fireChannelRead(msg);
 				}
+
+				@Override
+				public boolean isSharable() {
+					// Needed if multiple objects are stored in the bootstrap list
+					return true;
+				}
 			};
 			
 			FuzzyReflection fuzzy = FuzzyReflection.fromObject(serverConnection, true);

src/main/java/com/comphenix/protocol/injector/netty/ProtocolRegistry.java

@@ -1,125 +0,0 @@
-package com.comphenix.protocol.injector.netty;
-
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import com.comphenix.protocol.PacketType;
-import com.comphenix.protocol.PacketType.Protocol;
-import com.comphenix.protocol.PacketType.Sender;
-import com.comphenix.protocol.injector.packet.MapContainer;
-import com.comphenix.protocol.utility.MinecraftReflection;
-import com.google.common.collect.BiMap;
-import com.google.common.collect.HashBiMap;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
-
-/**
- * Represents a way of accessing the new netty Protocol enum.
- * @author Kristian
- */
-
-public abstract class ProtocolRegistry {
-	/**
-	 * Represents a register we are currently building.
-	 * @author Kristian
-	 */
-	protected static class Register {
-		// The main lookup table
-		public BiMap<PacketType, Class<?>> typeToClass = HashBiMap.create();
-		public volatile Set<PacketType> serverPackets = Sets.newHashSet();
-		public volatile Set<PacketType> clientPackets = Sets.newHashSet();
-		public List<MapContainer> containers = Lists.newArrayList();
-
-		public Register() {
-		}
-
-		/**
-		 * Determine if the current register is outdated.
-		 * @return TRUE if it is, FALSE otherwise.
-		 */
-		public boolean isOutdated() {
-			for (MapContainer container : containers) {
-				if (container.hasChanged()) {
-					return true;
-				}
-			}
-			return false;
-		}
-	}
-	
-	protected Class<?> enumProtocol;
-	
-	// Current register
-	protected volatile Register register;
-	
-	public ProtocolRegistry() {
-		enumProtocol = MinecraftReflection.getEnumProtocolClass();
-		initialize();
-	}
-	
-	/**
-	 * Retrieve an immutable view of the packet type lookup.
-	 * @return The packet type lookup.
-	 */
-	public Map<PacketType, Class<?>> getPacketTypeLookup() {
-		return Collections.unmodifiableMap(register.typeToClass);
-	}
-	
-	/**
-	 * Retrieve an immutable view of the class to packet type lookup.
-	 * @return The packet type lookup.
-	 */
-	public Map<Class<?>, PacketType> getPacketClassLookup() {
-		return Collections.unmodifiableMap(register.typeToClass.inverse());
-	}
-	
-	/**
-	 * Retrieve every known client packet, from every protocol.
-	 * @return Every client packet.
-	 */
-	public Set<PacketType> getClientPackets() {
-		return Collections.unmodifiableSet(register.clientPackets);
-	}
-	
-	/**
-	 * Retrieve every known server packet, from every protocol.
-	 * @return Every server packet.
-	 */
-	public Set<PacketType> getServerPackets() {
-		return Collections.unmodifiableSet(register.serverPackets);
-	}
-	
-	/**
-	 * Ensure that our local register is up-to-date with Minecraft.
-	 * <p>
-	 * This operation may block the calling thread.
-	 */
-	public synchronized void synchronize() {
-		// Check if the packet registry has changed
-		if (register.isOutdated()) {
-			initialize();
-		}
-	}
-	
-	/**
-	 * Load the packet lookup tables in each protocol.
-	 */
-	protected abstract void initialize();
-
-	protected abstract void associatePackets(Register register, Map<Integer, Class<?>> lookup, Protocol protocol, Sender sender);
-
-	/**
-	 * Retrieve the number of mapping in all the maps.
-	 * @param maps - iterable of maps.
-	 * @return The sum of all the entries.
-	 */
-	protected final int sum(Iterable<? extends Map<Integer, Class<?>>> maps) {
-		int count = 0;
-
-		for (Map<Integer, Class<?>> map : maps)
-			count += map.size();
-		return count;
-	}
-}

src/main/java/com/comphenix/protocol/injector/netty/SocketAdapter.java

@@ -43,8 +43,11 @@ public class SocketAdapter extends Socket {
         this.ch = ch;
     }
 
-    public static SocketAdapter adapt(SocketChannel ch) {
-        return new SocketAdapter(ch);
+    public static SocketAdapter adapt(Channel ch) {
+        if (!(ch instanceof SocketChannel)) {
+            return null;
+        }
+        return new SocketAdapter((SocketChannel) ch);
     }
 
     @Override

src/main/java/com/comphenix/protocol/injector/packet/PacketRegistry.java

@@ -17,42 +17,275 @@
 
 package com.comphenix.protocol.injector.packet;
 
-import java.util.Map;
-import java.util.Set;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.PacketType.Sender;
-import com.comphenix.protocol.injector.netty.NettyProtocolRegistry;
-import com.comphenix.protocol.injector.netty.ProtocolRegistry;
+import com.comphenix.protocol.ProtocolLogger;
+import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.StructureModifier;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
-import com.google.common.base.Function;
+import com.comphenix.protocol.utility.MinecraftVersion;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 
 /**
  * Static packet registry in Minecraft.
  * @author Kristian
  */
-@SuppressWarnings("rawtypes")
 public class PacketRegistry {
-	// The Netty packet registry
-	private static volatile ProtocolRegistry NETTY;
-
 	// Whether or not the registry has been initialized
 	private static volatile boolean INITIALIZED = false;
 
+	/**
+	 * Represents a register we are currently building.
+	 * @author Kristian
+	 */
+	protected static class Register {
+		// The main lookup table
+		private final Map<PacketType, Optional<Class<?>>> typeToClass = new ConcurrentHashMap<>();
+		private final Map<Class<?>, PacketType> classToType = new ConcurrentHashMap<>();
+
+		private volatile Set<PacketType> serverPackets = Sets.newHashSet();
+		private volatile Set<PacketType> clientPackets = Sets.newHashSet();
+		private final List<MapContainer> containers = Lists.newArrayList();
+
+		public Register() {}
+
+		public void registerPacket(PacketType type, Class<?> clazz, Sender sender) {
+			typeToClass.put(type, Optional.of(clazz));
+			classToType.put(clazz, type);
+			if (sender == Sender.CLIENT) {
+				clientPackets.add(type);
+			} else {
+				serverPackets.add(type);
+			}
+		}
+
+		public void addContainer(MapContainer container) {
+			containers.add(container);
+		}
+
+		/**
+		 * Determine if the current register is outdated.
+		 * @return TRUE if it is, FALSE otherwise.
+		 */
+		public boolean isOutdated() {
+			for (MapContainer container : containers) {
+				if (container.hasChanged()) {
+					return true;
+				}
+			}
+			return false;
+		}
+	}
+
+	protected static final Class<?> ENUM_PROTOCOL = MinecraftReflection.getEnumProtocolClass();
+
+	// Current register
+	protected static volatile Register REGISTER;
+
+	/**
+	 * Ensure that our local register is up-to-date with Minecraft.
+	 * <p>
+	 * This operation may block the calling thread.
+	 */
+	public static synchronized void synchronize() {
+		// Check if the packet registry has changed
+		if (REGISTER.isOutdated()) {
+			initialize();
+		}
+	}
+
+	protected static synchronized Register createOldRegister() {
+		Object[] protocols = ENUM_PROTOCOL.getEnumConstants();
+
+		// ID to Packet class maps
+		Map<Object, Map<Integer, Class<?>>> serverMaps = Maps.newLinkedHashMap();
+		Map<Object, Map<Integer, Class<?>>> clientMaps = Maps.newLinkedHashMap();
+
+		Register result = new Register();
+		StructureModifier<Object> modifier = null;
+
+		// Iterate through the protocols
+		for (Object protocol : protocols) {
+			if (modifier == null) {
+				modifier = new StructureModifier<>(protocol.getClass().getSuperclass(), false);
+			}
+
+			StructureModifier<Map<Object, Map<Integer, Class<?>>>> maps = modifier.withTarget(protocol).withType(Map.class);
+			for (Map.Entry<Object, Map<Integer, Class<?>>> entry : maps.read(0).entrySet()) {
+				String direction = entry.getKey().toString();
+				if (direction.contains("CLIENTBOUND")) { // Sent by Server
+					serverMaps.put(protocol, entry.getValue());
+				} else if (direction.contains("SERVERBOUND")) { // Sent by Client
+					clientMaps.put(protocol, entry.getValue());
+				}
+			}
+		}
+
+		// Maps we have to occasionally check have changed
+		for (Object map : serverMaps.values()) {
+			result.addContainer(new MapContainer(map));
+		}
+
+		for (Object map : clientMaps.values()) {
+			result.addContainer(new MapContainer(map));
+		}
+
+		for (Object protocol : protocols) {
+			Enum<?> enumProtocol = (Enum<?>) protocol;
+			PacketType.Protocol equivalent = PacketType.Protocol.fromVanilla(enumProtocol);
+
+			// Associate known types
+			if (serverMaps.containsKey(protocol))
+				associatePackets(result, serverMaps.get(protocol), equivalent, Sender.SERVER);
+			if (clientMaps.containsKey(protocol))
+				associatePackets(result, clientMaps.get(protocol), equivalent, Sender.CLIENT);
+		}
+
+		return result;
+	}
+
+	@SuppressWarnings("unchecked")
+	private static synchronized Register createNewRegister() {
+		Object[] protocols = ENUM_PROTOCOL.getEnumConstants();
+
+		// ID to Packet class maps
+		Map<Object, Map<Class<?>, Integer>> serverMaps = Maps.newLinkedHashMap();
+		Map<Object, Map<Class<?>, Integer>> clientMaps = Maps.newLinkedHashMap();
+
+		Register result = new Register();
+		Field mainMapField = null;
+		Field packetMapField = null;
+
+		// Iterate through the protocols
+		for (Object protocol : protocols) {
+			if (mainMapField == null) {
+				FuzzyReflection fuzzy = FuzzyReflection.fromClass(protocol.getClass(), true);
+				mainMapField = fuzzy.getField(FuzzyFieldContract.newBuilder()
+						.banModifier(Modifier.STATIC)
+						.requireModifier(Modifier.FINAL)
+						.typeDerivedOf(Map.class)
+						.build());
+				mainMapField.setAccessible(true);
+			}
+
+			Map<Object, Object> directionMap;
+
+			try {
+				directionMap = (Map<Object, Object>) mainMapField.get(protocol);
+			} catch (ReflectiveOperationException ex) {
+				throw new RuntimeException("Failed to access packet map", ex);
+			}
+
+			for (Map.Entry<Object, Object> entry : directionMap.entrySet()) {
+				Object holder = entry.getValue();
+				if (packetMapField == null) {
+					FuzzyReflection fuzzy = FuzzyReflection.fromClass(holder.getClass(), true);
+					packetMapField = fuzzy.getField(FuzzyFieldContract.newBuilder()
+							.banModifier(Modifier.STATIC)
+							.requireModifier(Modifier.FINAL)
+							.typeDerivedOf(Map.class)
+							.build());
+					packetMapField.setAccessible(true);
+				}
+
+				Map<Class<?>, Integer> packetMap;
+
+				try {
+					packetMap = (Map<Class<?>, Integer>) packetMapField.get(holder);
+				} catch (ReflectiveOperationException ex) {
+					throw new RuntimeException("Failed to access packet map", ex);
+				}
+
+				String direction = entry.getKey().toString();
+				if (direction.contains("CLIENTBOUND")) { // Sent by Server
+					serverMaps.put(protocol, packetMap);
+				} else if (direction.contains("SERVERBOUND")) { // Sent by Client
+					clientMaps.put(protocol, packetMap);
+				}
+			}
+		}
+
+		// Maps we have to occasionally check have changed
+		// TODO: Find equivalent in Object2IntMap
+
+		/* for (Object map : serverMaps.values()) {
+			result.containers.add(new MapContainer(map));
+		}
+
+		for (Object map : clientMaps.values()) {
+			result.containers.add(new MapContainer(map));
+		} */
+
+		for (Object protocol : protocols) {
+			Enum<?> enumProtocol = (Enum<?>) protocol;
+			PacketType.Protocol equivalent = PacketType.Protocol.fromVanilla(enumProtocol);
+
+			// Associate known types
+			if (serverMaps.containsKey(protocol)) {
+				associatePackets(result, reverse(serverMaps.get(protocol)), equivalent, Sender.SERVER);
+			}
+			if (clientMaps.containsKey(protocol)) {
+				associatePackets(result, reverse(clientMaps.get(protocol)), equivalent, Sender.CLIENT);
+			}
+		}
+
+		return result;
+	}
+
+	/**
+	 * Reverses a key->value map to value->key
+	 * Non-deterministic behavior when multiple keys are mapped to the same value
+	 */
+	private static <K, V> Map<V, K> reverse(Map<K, V> map) {
+		Map<V, K> newMap = new HashMap<>(map.size());
+		for (Map.Entry<K, V> entry : map.entrySet()) {
+			newMap.put(entry.getValue(), entry.getKey());
+		}
+		return newMap;
+	}
+
+	protected static void associatePackets(Register register, Map<Integer, Class<?>> lookup, PacketType.Protocol protocol, Sender sender) {
+		for (Map.Entry<Integer, Class<?>> entry : lookup.entrySet()) {
+			PacketType type = PacketType.fromCurrent(protocol, sender, entry.getKey(), entry.getValue());
+
+			try {
+				register.registerPacket(type, entry.getValue(), sender);
+			} catch (Exception ex) {
+				ProtocolLogger.debug("Encountered an exception associating packet " + type, ex);
+			}
+		}
+	}
+
+	private static void associate(PacketType type, Class<?> clazz) {
+		if (clazz != null) {
+			REGISTER.typeToClass.put(type, Optional.of(clazz));
+			REGISTER.classToType.put(clazz, type);
+		} else {
+			REGISTER.typeToClass.put(type, Optional.empty());
+		}
+	}
+
 	/**
 	 * Initializes the packet registry.
 	 */
 	private static void initialize() {
-		if (INITIALIZED) {
-			if (NETTY == null) {
-				throw new IllegalStateException("Failed to initialize packet registry.");
-			}
-			return;
-		}
+		if (!INITIALIZED) {
+			INITIALIZED = true;
 
-		NETTY = new NettyProtocolRegistry();
-		INITIALIZED = true;
+			if (MinecraftVersion.BEE_UPDATE.atOrAbove()) {
+				REGISTER = createNewRegister();
+			} else {
+				REGISTER = createOldRegister();
+			}
+		}
 	}
 
 	/**
@@ -62,35 +295,7 @@ public class PacketRegistry {
 	 */
 	public static boolean isSupported(PacketType type) {
 		initialize();
-		return NETTY.getPacketTypeLookup().containsKey(type);
-	}
-
-	/**
-	 * Retrieve a map of every packet class to every ID.
-	 * <p>
-	 * Deprecated: Use {@link #getPacketToType()} instead.
-	 * @return A map of packet classes and their corresponding ID.
-	 */
-	@Deprecated
-	public static Map<Class, Integer> getPacketToID() {
-		initialize();
-
-		@SuppressWarnings("unchecked")
-		Map<Class, Integer> result = (Map) Maps.transformValues(
-				NETTY.getPacketClassLookup(), PacketType::getCurrentId);
-		return result;
-	}
-
-	/**
-	 * Retrieve a map of every packet class to the respective packet type.
-	 * @return A map of packet classes and their corresponding packet type.
-	 */
-	public static Map<Class, PacketType> getPacketToType() {
-		initialize();
-
-		@SuppressWarnings("unchecked")
-		Map<Class, PacketType> result = (Map) NETTY.getPacketClassLookup();
-		return result;
+		return tryGetPacketClass(type).isPresent();
 	}
 
 	/**
@@ -99,9 +304,9 @@ public class PacketRegistry {
 	 */
 	public static Set<PacketType> getServerPacketTypes() {
 		initialize();
-		NETTY.synchronize();
+		synchronize();
 
-		return NETTY.getServerPackets();
+		return Collections.unmodifiableSet(REGISTER.serverPackets);
 	}
 	
 	/**
@@ -110,88 +315,68 @@ public class PacketRegistry {
 	 */
 	public static Set<PacketType> getClientPacketTypes() {
 		initialize();
-		NETTY.synchronize();
+		synchronize();
 
-		return NETTY.getClientPackets();
+		return Collections.unmodifiableSet(REGISTER.clientPackets);
+	}
+
+	private static Class<?> searchForPacket(List<String> classNames) {
+		for (String name : classNames) {
+			try {
+				Class<?> clazz = MinecraftReflection.getMinecraftClass(name);
+				if (MinecraftReflection.getPacketClass().isAssignableFrom(clazz)
+						&& !Modifier.isAbstract(clazz.getModifiers())) {
+					return clazz;
+				}
+			} catch (Exception ignored) {}
+		}
+
+		return null;
 	}
 
-	/**
-	 * Retrieves the correct packet class from a given packet ID.
-	 * <p>
-	 * Deprecated: Use {@link #getPacketClassFromType(PacketType)} instead.
-	 * @param packetID - the packet ID.
-	 * @return The associated class.
-	 */
-	@Deprecated
-	public static Class getPacketClassFromID(int packetID) {
-		initialize();
-		return NETTY.getPacketTypeLookup().get(PacketType.findLegacy(packetID));
-	}
-	
 	/**
 	 * Retrieves the correct packet class from a given type.
-	 * @param type - the packet type.
-	 * @return The associated class.
-	 */
-	public static Class getPacketClassFromType(PacketType type) {
-		return getPacketClassFromType(type, false);
-	}
-	
-	/**
-	 * Retrieves the correct packet class from a given type.
-	 * <p>
-	 * Note that forceVanillla will be ignored on MC 1.7.2 and later.
+	 *
 	 * @param type - the packet type.
 	 * @param forceVanilla - whether or not to look for vanilla classes, not injected classes.
 	 * @return The associated class.
+	 * @deprecated forceVanilla no longer has any effect
 	 */
-	public static Class getPacketClassFromType(PacketType type, boolean forceVanilla) {
+	@Deprecated
+	public static Class<?> getPacketClassFromType(PacketType type, boolean forceVanilla) {
+		return getPacketClassFromType(type);
+	}
+
+	public static Optional<Class<?>> tryGetPacketClass(PacketType type) {
 		initialize();
 
-		// Try the lookup first
-		Class<?> clazz = NETTY.getPacketTypeLookup().get(type);
-		if (clazz != null) {
-			return clazz;
+		// Try the lookup first (may be null, so check contains)
+		Optional<Class<?>> res = REGISTER.typeToClass.get(type);
+		if (res != null) {
+			return res;
 		}
 
 		// Then try looking up the class names
-		for (String name : type.getClassNames()) {
-			try {
-				clazz = MinecraftReflection.getMinecraftClass(name);
-				break;
-			} catch (Exception ignored) { }
+		Class<?> clazz = searchForPacket(type.getClassNames());
+		if (clazz != null) {
+			// we'd like for it to be associated correctly from the get-go; this is OK on older versions though
+			ProtocolLogger.warnAbove(type.getCurrentVersion(), "Updating associated class for {0} to {1}", type.name(), clazz);
 		}
 
-		// TODO Cache the result?
-		return clazz;
+		// cache it for next time
+		associate(type, clazz);
+		return Optional.ofNullable(clazz);
 	}
 
 	/**
-	 * Retrieves the correct packet class from a given packet ID.
-	 * <p>
-	 * This method has been deprecated.
-	 * @param packetID - the packet ID.
- 	 * @param forceVanilla - whether or not to look for vanilla classes, not injected classes.
-	 * @return The associated class.
+	 * Get the packet class associated with a given type. First attempts to read from the
+	 * type-to-class mapping, and tries
+	 * @param type the packet type
+	 * @return The associated class
 	 */
-	@Deprecated
-	public static Class getPacketClassFromID(int packetID, boolean forceVanilla) {
-		initialize();
-		return getPacketClassFromID(packetID);
-	}
-
-	/**
-	 * Retrieve the packet ID of a given packet.
-	 * <p>
-	 * Deprecated: Use {@link #getPacketType(Class)}.
-	 * @param packet - the type of packet to check.
-	 * @return The legacy ID of the given packet.
-	 * @throws IllegalArgumentException If this is not a valid packet.
-	 */
-	@Deprecated
-	public static int getPacketID(Class<?> packet) {
-		initialize();
-		return NETTY.getPacketClassLookup().get(packet).getCurrentId();
+	public static Class<?> getPacketClassFromType(PacketType type) {
+		return tryGetPacketClass(type)
+				.orElseThrow(() -> new IllegalArgumentException("Could not find packet for type " + type.name()));
 	}
 
 	/**
@@ -200,7 +385,8 @@ public class PacketRegistry {
 	 * @return The packet type, or NULL if not found.
 	 */
 	public static PacketType getPacketType(Class<?> packet) {
-		return getPacketType(packet, null);
+		initialize();
+		return REGISTER.classToType.get(packet);
 	}
 	
 	/**
@@ -208,9 +394,10 @@ public class PacketRegistry {
 	 * @param packet - the class of the packet.
 	 * @param sender - the sender of the packet, or NULL.
 	 * @return The packet type, or NULL if not found.
+	 * @deprecated sender no longer has any effect
 	 */
+	@Deprecated
 	public static PacketType getPacketType(Class<?> packet, Sender sender) {
-		initialize();
-		return NETTY.getPacketClassLookup().get(packet);
+		return getPacketType(packet);
 	}
 }

src/main/java/com/comphenix/protocol/injector/server/BukkitSocketInjector.java

@@ -80,4 +80,9 @@ public class BukkitSocketInjector implements SocketInjector {
 	public void setUpdatedPlayer(Player updatedPlayer) {
 		this.player = updatedPlayer;
 	}
+
+	@Override
+	public boolean isConnected() {
+		return player.isOnline();
+	}
 }

src/main/java/com/comphenix/protocol/injector/server/SocketInjector.java

@@ -18,22 +18,24 @@ public interface SocketInjector {
 	 * Retrieve the associated socket of this player.
 	 * @return The associated socket.
 	 * @throws IllegalAccessException If we're unable to read the socket field.
+	 * @deprecated May be null on certain server implementations. Also don't use raw sockets.
 	 */
-	public abstract Socket getSocket() throws IllegalAccessException;
+	@Deprecated
+	Socket getSocket() throws IllegalAccessException;
 
 	/**
 	 * Retrieve the associated address of this player.
 	 * @return The associated address.
 	 * @throws IllegalAccessException If we're unable to read the socket field.
 	 */
-	public abstract SocketAddress getAddress() throws IllegalAccessException;
+	SocketAddress getAddress() throws IllegalAccessException;
 
 	/**
 	 * Attempt to disconnect the current client.
 	 * @param message - the message to display.
 	 * @throws InvocationTargetException If disconnection failed.
 	 */
-	public abstract void disconnect(String message) throws InvocationTargetException;
+	void disconnect(String message) throws InvocationTargetException;
 
 	/**
 	 * Send a packet to the client.
@@ -42,30 +44,36 @@ public interface SocketInjector {
 	 * @param filtered - whether or not the packet will be filtered by our listeners.
 	 * @throws InvocationTargetException If an error occured when sending the packet.
 	 */
-	public abstract void sendServerPacket(Object packet, NetworkMarker marker, boolean filtered)
+	void sendServerPacket(Object packet, NetworkMarker marker, boolean filtered)
 			throws InvocationTargetException;
 
 	/**
 	 * Retrieve the hooked player.
 	 * @return The hooked player.
 	 */
-	public abstract Player getPlayer();
+	Player getPlayer();
 
 	/**
 	 * Retrieve the hooked player object OR the more up-to-date player instance.
 	 * @return The hooked player, or a more up-to-date instance.
 	 */
-	public abstract Player getUpdatedPlayer();
+	Player getUpdatedPlayer();
 
 	/**
 	 * Invoked when a delegated socket injector transfers the state of one injector to the next.
 	 * @param delegate - the new injector.
 	 */
-	public abstract void transferState(SocketInjector delegate);
+	void transferState(SocketInjector delegate);
 
 	/**
 	 * Set the real Bukkit player that we will use.
 	 * @param updatedPlayer - the real Bukkit player.
 	 */
-	public abstract void setUpdatedPlayer(Player updatedPlayer);
+	void setUpdatedPlayer(Player updatedPlayer);
+
+	/**
+	 * Determines if the player is currently connected.
+	 * @return true if the player is connected.
+	 */
+	boolean isConnected();
 }

src/main/java/com/comphenix/protocol/injector/server/TemporaryPlayerFactory.java

@@ -157,9 +157,9 @@ public class TemporaryPlayerFactory {
 
 				// Methods that are supported in the fallback instance
 				if (methodName.equals("isOnline"))
-					return injector.getSocket() != null && injector.getSocket().isConnected();
+					return injector.isConnected();
 				else if (methodName.equals("getName"))
-					return "UNKNOWN[" + injector.getSocket().getRemoteSocketAddress() + "]";
+					return "UNKNOWN[" + injector.getAddress() + "]";
 
 				// Ignore all other methods
 				throw new UnsupportedOperationException(

src/main/java/com/comphenix/protocol/metrics/Metrics.java

@@ -2,7 +2,6 @@ package com.comphenix.protocol.metrics;
 
 import org.bukkit.Bukkit;
 import org.bukkit.configuration.file.YamlConfiguration;
-import org.bukkit.craftbukkit.libs.org.apache.commons.lang3.tuple.Pair;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.RegisteredServiceProvider;

src/main/java/com/comphenix/protocol/metrics/Statistics.java

@@ -24,7 +24,6 @@ import com.comphenix.protocol.events.PacketListener;
 import com.comphenix.protocol.utility.Util;
 
 import org.bukkit.Bukkit;
-import org.bukkit.craftbukkit.libs.org.apache.commons.lang3.tuple.Pair;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -87,13 +86,7 @@ public class Statistics {
 
 		for (PacketListener listener : ProtocolLibrary.getProtocolManager().getPacketListeners()) {
 			String name = PacketAdapter.getPluginName(listener);
-
-			// Increment occurence
-			if (!users.containsKey(name)) {
-				users.put(name, 1);
-			} else {
-				users.put(name, users.get(name) + 1);
-			}
+			users.put(name, 1);
 		}
 
 		return users;

src/main/java/com/comphenix/protocol/reflect/ObjectWriter.java

@@ -117,12 +117,11 @@ public class ObjectWriter {
 			}
 			
 			// Copy private fields underneath
-			Class<?> superclass = commonType.getSuperclass();
-			
-			if (superclass != null && !superclass.equals(Object.class)) {
-				copyToInternal(source, destination, superclass, false);
-			}
-			
+//			Class<?> superclass = commonType.getSuperclass();
+//
+//			if (superclass != null && !superclass.equals(Object.class)) {
+//				copyToInternal(source, destination, superclass, false);
+//			}
 		} catch (FieldAccessException e) {
 			throw new RuntimeException("Unable to copy fields from " + commonType.getName(), e);
 		}

src/main/java/com/comphenix/protocol/reflect/accessors/Accessors.java

@@ -289,6 +289,7 @@ public final class Accessors {
 	 * @return The method accessor.
 	 */
 	public static ConstructorAccessor getConstructorAccessor(final Constructor<?> constructor) {
+		constructor.setAccessible(true); // let us in even if we are not allowed to
 		return new DefaultConstrutorAccessor(constructor);
 	}
 	

src/main/java/com/comphenix/protocol/reflect/cloning/AggregateCloner.java

@@ -256,11 +256,11 @@ public class AggregateCloner implements Cloner {
 		if (index < cloners.size()) {
 			Cloner cloner = cloners.get(index);
 
-			try {
-				return cloner.clone(source);
-			} catch (Exception ex) {
-				throw new RuntimeException("Failed to clone " + source + " (" + source.getClass() + ") with " + cloner, ex);
-			}
+//			try {
+			return cloner.clone(source);
+//			} catch (Exception ex) {
+//				throw new RuntimeException("Failed to clone " + source + " (" + source.getClass() + ") with " + cloner, ex);
+//			}
 		}
 
 		// Damn - failure

src/main/java/com/comphenix/protocol/reflect/cloning/BukkitCloner.java

@@ -88,6 +88,11 @@ public class BukkitCloner implements Cloner {
 			fromManual(ComponentConverter::getBaseComponentArrayClass, source ->
 					ComponentConverter.clone((BaseComponent[]) source));
 		} catch (Throwable ignored) { }
+
+		try {
+			fromManual(AdventureComponentConverter::getComponentClass, source ->
+					AdventureComponentConverter.clone(source));
+		} catch (Throwable ignored) { }
 	}
 
 	private Function<Object, Object> findCloner(Class<?> type) {

src/main/java/com/comphenix/protocol/reflect/cloning/ImmutableDetector.java

@@ -62,29 +62,29 @@ public class ImmutableDetector implements Cloner {
 		add(MinecraftReflection::getDataWatcherSerializerClass);
 		add(MinecraftReflection::getBlockClass);
 		add(MinecraftReflection::getItemClass);
-		add("SoundEffect");
+		add("sounds.SoundEffect", "SoundEffect");
 
 		if (MinecraftVersion.AQUATIC_UPDATE.atOrAbove()) {
 			add(MinecraftReflection::getFluidTypeClass);
 			add(MinecraftReflection::getParticleTypeClass);
-			add("Particle");
+			add("core.particles.Particle", "Particle");
 		}
 
 		if (MinecraftVersion.VILLAGE_UPDATE.atOrAbove()) {
-			add("EntityTypes");
-			add("VillagerType");
-			add("VillagerProfession");
+			add(MinecraftReflection::getEntityTypes);
+			add("world.entity.npc.VillagerType", "VillagerType");
+			add("world.entity.npc.VillagerProfession", "VillagerProfession");
 		}
 
 		// TODO automatically detect the technically-not-an-enum enums that Mojang is so fond of
 		// Would also probably go in tandem with having the FieldCloner use this
 
 		if (MinecraftVersion.NETHER_UPDATE.atOrAbove()) {
-			add("IRegistry");
+			add("core.IRegistry", "IRegistry");
 		}
 
 		if (MinecraftVersion.NETHER_UPDATE_2.atOrAbove()) {
-			add("ResourceKey");
+			add(MinecraftReflection::getResourceKey);
 		}
 	}
 
@@ -97,13 +97,11 @@ public class ImmutableDetector implements Cloner {
 		} catch (RuntimeException ignored) { }
 	}
 
-	private static void add(String className) {
-		try {
-			Class<?> clazz = MinecraftReflection.getMinecraftClass(className);
-			if (clazz != null) {
-				immutableNMS.add(clazz);
-			}
-		} catch (RuntimeException ignored) { }
+	private static void add(String className, String... aliases) {
+		Class<?> clazz = MinecraftReflection.getNullableNMS(className, aliases);
+		if (clazz != null) {
+			immutableNMS.add(clazz);
+		}
 	}
 	
 	@Override

src/main/java/com/comphenix/protocol/reflect/compiler/StructureCompiler.java

@@ -141,6 +141,18 @@ public final class StructureCompiler {
 	private static String COMPILED_CLASS = PACKAGE_NAME + "/CompiledStructureModifier";
 	private static String FIELD_EXCEPTION_CLASS = "com/comphenix/protocol/reflect/FieldAccessException";
 
+	// On java 9+ (53.0+) CLassLoader#defineClass(String, byte[], int, int) should not be used anymore.
+	// It will throw warnings and on Java 16+ (60.0+), it does not work at all anymore.
+	private static final boolean LEGACY_CLASS_DEFINITION =
+			Float.parseFloat(System.getProperty("java.class.version")) < 53;
+	/**
+	 * The MethodHandles.Lookup object for this compiler. Only used when using the modern defineClass strategy.
+	 */
+	private Object lookup = null;
+
+	// Used to get the MethodHandles.Lookup object on newer versions of Java.
+	private volatile static Method lookupMethod;
+
 	public static boolean attemptClassLoad = false;
 
 	/**
@@ -289,36 +301,54 @@ public final class StructureCompiler {
 
 		byte[] data = cw.toByteArray();
 
-		// Call the define method
+		Class<?> clazz = defineClass(data);
+		// DEBUG CODE: Print the content of the generated class.
+		//org.objectweb.asm.ClassReader cr = new org.objectweb.asm.ClassReader(data);
+		//cr.accept(new ASMifierClassVisitor(new PrintWriter(System.out)), 0);
+		return clazz;
+	}
+
+	private Class<?> defineClassLegacy(byte[] data) throws InvocationTargetException, IllegalAccessException,
+			NoSuchMethodException {
+		if (defineMethod == null) {
+			Method defined = ClassLoader.class.getDeclaredMethod("defineClass",
+					new Class<?>[]{String.class, byte[].class, int.class, int.class});
+
+			// Awesome. Now, create and return it.
+			defined.setAccessible(true);
+			defineMethod = defined;
+		}
+		return (Class<?>) defineMethod.invoke(loader, null, data, 0, data.length);
+	}
+
+	private Class<?> defineClassModern(byte[] data) throws InvocationTargetException, IllegalAccessException,
+			ClassNotFoundException, NoSuchMethodException {
+		if (defineMethod == null) {
+			defineMethod = Class.forName("java.lang.invoke.MethodHandles$Lookup")
+					.getDeclaredMethod("defineClass", byte[].class);
+		}
+		if (lookupMethod == null) {
+			lookupMethod = Class.forName("java.lang.invoke.MethodHandles").getDeclaredMethod("lookup");
+		}
+		if (lookup == null)
+			lookup = lookupMethod.invoke(null);
+
+		return (Class<?>) defineMethod.invoke(lookup, data);
+	}
+
+	private Class<?> defineClass(byte[] data) {
 		try {
-			if (defineMethod == null) {
-				Method defined = ClassLoader.class.getDeclaredMethod("defineClass",
-					new Class<?>[] { String.class, byte[].class, int.class, int.class });
-
-				// Awesome. Now, create and return it.
-				defined.setAccessible(true);
-				defineMethod = defined;
-			}
-
-			@SuppressWarnings("rawtypes")
-			Class clazz = (Class) defineMethod.invoke(loader, null, data, 0, data.length);
-
-			// DEBUG CODE: Print the content of the generated class.
-			//org.objectweb.asm.ClassReader cr = new org.objectweb.asm.ClassReader(data);
-	        //cr.accept(new ASMifierClassVisitor(new PrintWriter(System.out)), 0);
-
-			return clazz;
-
+			return LEGACY_CLASS_DEFINITION ? defineClassLegacy(data) : defineClassModern(data);
 		} catch (SecurityException e) {
 			throw new RuntimeException("Cannot use reflection to dynamically load a class.", e);
-		} catch (NoSuchMethodException e) {
+		} catch (NoSuchMethodException | ClassNotFoundException e) {
 			throw new IllegalStateException("Incompatible JVM.", e);
 		} catch (IllegalArgumentException e) {
 			throw new IllegalStateException("Cannot call defineMethod - wrong JVM?", e);
 		} catch (IllegalAccessException e) {
 			throw new RuntimeException("Security limitation! Cannot dynamically load class.", e);
 		} catch (InvocationTargetException e) {
-			throw new RuntimeException("Error occured in code generator.", e);
+			throw new RuntimeException("Error occurred in code generator.", e);
 		}
 	}
 

src/main/java/com/comphenix/protocol/reflect/instances/DefaultInstances.java

@@ -17,32 +17,31 @@
 
 package com.comphenix.protocol.reflect.instances;
 
+import com.comphenix.protocol.ProtocolLogger;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.google.common.base.Objects;
+import com.google.common.collect.ImmutableList;
+
+import javax.annotation.Nullable;
 import java.lang.reflect.Constructor;
 import java.util.Collection;
 import java.util.List;
-import java.util.UUID;
 import java.util.logging.Level;
 
-import javax.annotation.Nullable;
-
-import com.comphenix.protocol.ProtocolLogger;
-import com.google.common.base.Objects;
-import com.google.common.collect.ImmutableList;
-
 /**
  * Used to construct default instances of any type.
  * @author Kristian
- *
  */
 public class DefaultInstances implements InstanceProvider {
 
-	public static final InstanceProvider UUID_GENERATOR = type -> type == UUID.class ? new UUID(0L, 0L) : null;
-
 	/**
 	 * Standard default instance provider.
 	 */
 	public static final DefaultInstances DEFAULT = DefaultInstances.fromArray(
-			PrimitiveGenerator.INSTANCE, CollectionGenerator.INSTANCE, UUID_GENERATOR);
+			PrimitiveGenerator.INSTANCE,
+			CollectionGenerator.INSTANCE,
+			MinecraftGenerator.INSTANCE
+	);
 
 	/**
 	 * The maximum height of the heirarchy of creates types. Used to prevent cycles.
@@ -188,7 +187,7 @@ public class DefaultInstances implements InstanceProvider {
 			// Note that we don't allow recursive types - that is, types that
 			// require itself in the constructor.
 			if (types.length < lastCount) {
-				if (!contains(types, type)) {
+				if (!contains(types, type) && !contains(types, MinecraftReflection.getPacketDataSerializerClass())) {
 					if (nonNull) {
 						// Make sure all of these types are non-null
 						if (isAnyNull(types, providers, recursionLevel)) {
@@ -273,7 +272,6 @@ public class DefaultInstances implements InstanceProvider {
 		Constructor<T> minimum = getMinimumConstructor(type, providers, recursionLevel + 1);
 
 		// Create the type with this constructor using default values. This might fail, though.
-		// TODO every packet has a zero-args constructor
 
 		try {
 			if (minimum != null) {

src/main/java/com/comphenix/protocol/reflect/instances/MinecraftGenerator.java

@@ -0,0 +1,77 @@
+package com.comphenix.protocol.reflect.instances;
+
+import com.comphenix.protocol.reflect.accessors.MethodAccessor;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.wrappers.BukkitConverters;
+import org.bukkit.Material;
+import org.bukkit.entity.EntityType;
+import org.bukkit.inventory.ItemStack;
+
+import java.lang.reflect.Constructor;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class MinecraftGenerator {
+    // system unique id representation
+    public static final UUID SYS_UUID;
+    // minecraft default types
+    public static final Object AIR_ITEM_STACK;
+    private static Object DEFAULT_ENTITY_TYPES; // modern servers only (older servers will use an entity type id)
+    // minecraft method accessors
+    private static final MethodAccessor NON_NULL_LIST_CREATE;
+    // fast util mappings for paper relocation
+    private static final Map<Class<?>, Constructor<?>> FAST_MAP_CONSTRUCTORS;
+
+    static {
+        try {
+            SYS_UUID = new UUID(0L, 0L);
+            AIR_ITEM_STACK = BukkitConverters.getItemStackConverter().getGeneric(new ItemStack(Material.AIR));
+            FAST_MAP_CONSTRUCTORS = new ConcurrentHashMap<>();
+            NON_NULL_LIST_CREATE = MinecraftReflection.getNonNullListCreateAccessor();
+        } catch (Throwable ex) {
+            throw new RuntimeException("Failed to create static fields in MinecraftGenerator", ex);
+        }
+    }
+
+    public static final InstanceProvider INSTANCE = type -> {
+        if (type != null) {
+            if (type == UUID.class) {
+                return SYS_UUID;
+            } else if (type.isEnum()) {
+                return type.getEnumConstants()[0];
+            } else if (type == MinecraftReflection.getItemStackClass()) {
+                return AIR_ITEM_STACK;
+            } else if (type == MinecraftReflection.getEntityTypes()) {
+                if (DEFAULT_ENTITY_TYPES == null) {
+                    // try to initialize now
+                    try {
+                        DEFAULT_ENTITY_TYPES = BukkitConverters.getEntityTypeConverter().getGeneric(EntityType.AREA_EFFECT_CLOUD);
+                    } catch (Exception ignored) {
+                        // not available in this version of minecraft
+                    }
+                }
+                return DEFAULT_ENTITY_TYPES;
+            } else if (type.isAssignableFrom(Map.class)) {
+                Constructor<?> ctor = FAST_MAP_CONSTRUCTORS.computeIfAbsent(type, __ -> {
+                    try {
+                        String name = type.getCanonicalName();
+                        if (name != null && name.contains("it.unimi.fastutils")) {
+                            return Class.forName(name.substring(name.length() - 3) + "OpenHashMap").getConstructor();
+                        }
+                    } catch (Exception ignored) {}
+                    return null;
+                });
+                if (ctor != null) {
+                    try {
+                        return ctor.newInstance();
+                    } catch (ReflectiveOperationException ignored) {}
+                }
+            } else if (NON_NULL_LIST_CREATE != null && type == MinecraftReflection.getNonNullListClass()) {
+                return NON_NULL_LIST_CREATE.invoke(null);
+            }
+        }
+
+        return null;
+    };
+}

src/main/java/com/comphenix/protocol/utility/Constants.java

@@ -21,10 +21,10 @@ package com.comphenix.protocol.utility;
  */
 
 public final class Constants {
-	public static final String PACKAGE_VERSION = "v1_16_R3";
-	public static final String NMS = "net.minecraft.server." + PACKAGE_VERSION;
+	public static final String PACKAGE_VERSION = "v1_17_R1";
+	public static final String NMS = "net.minecraft";
 	public static final String OBC = "org.bukkit.craftbukkit." + PACKAGE_VERSION;
-	public static final MinecraftVersion CURRENT_VERSION = MinecraftVersion.NETHER_UPDATE_2;
+	public static final MinecraftVersion CURRENT_VERSION = MinecraftVersion.CAVES_CLIFFS_1;
 
 	public static void init() {
 		MinecraftReflection.setMinecraftPackage(NMS, OBC);

src/main/java/com/comphenix/protocol/utility/MinecraftMethods.java

@@ -248,8 +248,8 @@ public class MinecraftMethods {
 				}
 			}
 
-			if (packetReadByteBuf == null)
-				throw new IllegalStateException("Unable to find Packet.read(PacketDataSerializer)");
+//			if (packetReadByteBuf == null)
+//				throw new IllegalStateException("Unable to find Packet.read(PacketDataSerializer)");
 			if (packetWriteByteBuf == null)
 				throw new IllegalStateException("Unable to find Packet.write(PacketDataSerializer)");
 		}

src/main/java/com/comphenix/protocol/utility/MinecraftProtocolVersion.java

@@ -72,6 +72,10 @@ public class MinecraftProtocolVersion {
 		map.put(new MinecraftVersion(1, 16, 2), 751);
 		map.put(new MinecraftVersion(1, 16, 3), 753);
 		map.put(new MinecraftVersion(1, 16, 4), 754);
+		map.put(new MinecraftVersion(1, 16, 5), 754);
+
+		map.put(new MinecraftVersion(1, 17, 0), 755);
+		map.put(new MinecraftVersion(1, 17, 1), 756);
 		return map;
 	}
 

src/main/java/com/comphenix/protocol/utility/MinecraftReflection.java

@@ -27,10 +27,8 @@ import java.lang.reflect.Modifier;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.net.InetAddress;
-import java.net.ServerSocket;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentMap;
@@ -57,6 +55,7 @@ import com.comphenix.protocol.reflect.ClassAnalyser;
 import com.comphenix.protocol.reflect.ClassAnalyser.AsmMethod;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 import com.comphenix.protocol.reflect.accessors.MethodAccessor;
 import com.comphenix.protocol.reflect.fuzzy.AbstractFuzzyMatcher;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyClassContract;
@@ -65,6 +64,7 @@ import com.comphenix.protocol.reflect.fuzzy.FuzzyMatchers;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.utility.RemappedClassSource.RemapperUnavailableException;
 import com.comphenix.protocol.utility.RemappedClassSource.RemapperUnavailableException.Reason;
+import com.comphenix.protocol.wrappers.EnumWrappers;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
 import com.comphenix.protocol.wrappers.nbt.NbtType;
 import com.google.common.base.Joiner;
@@ -222,30 +222,35 @@ public class MinecraftReflection {
 				Class<?> craftEntity = getCraftEntityClass();
 				Method getHandle = craftEntity.getMethod("getHandle");
 
-				MINECRAFT_FULL_PACKAGE = getPackage(getHandle.getReturnType().getCanonicalName());
-
-				// Pretty important invariantt
-				if (!MINECRAFT_FULL_PACKAGE.startsWith(MINECRAFT_PREFIX_PACKAGE)) {
-					// See if we got the Forge entity package
-					if (MINECRAFT_FULL_PACKAGE.equals(FORGE_ENTITY_PACKAGE)) {
-						// USe the standard NMS versioned package
-						MINECRAFT_FULL_PACKAGE = CachedPackage.combine(MINECRAFT_PREFIX_PACKAGE, packageVersion);
-					} else {
-						// Assume they're the same instead
-						MINECRAFT_PREFIX_PACKAGE = MINECRAFT_FULL_PACKAGE;
-					}
-
-					// The package is usualy flat, so go with that assumption
-					String matcher =
-							(MINECRAFT_PREFIX_PACKAGE.length() > 0 ?
-									Pattern.quote(MINECRAFT_PREFIX_PACKAGE + ".") : "") + CANONICAL_REGEX;
-
-					// We'll still accept the default location, however
-					setDynamicPackageMatcher("(" + matcher + ")|(" + MINECRAFT_OBJECT + ")");
-
-				} else {
-					// Use the standard matcher
+				if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+					// total rework of the NMS structure in 1.17 (at least there's no versioning)
+					MINECRAFT_FULL_PACKAGE = MINECRAFT_PREFIX_PACKAGE = "net.minecraft";
 					setDynamicPackageMatcher(MINECRAFT_OBJECT);
+				} else {
+					MINECRAFT_FULL_PACKAGE = getPackage(getHandle.getReturnType().getCanonicalName());
+
+					// Pretty important invariantt
+					if (!MINECRAFT_FULL_PACKAGE.startsWith(MINECRAFT_PREFIX_PACKAGE)) {
+						// See if we got the Forge entity package
+						if (MINECRAFT_FULL_PACKAGE.equals(FORGE_ENTITY_PACKAGE)) {
+							// USe the standard NMS versioned package
+							MINECRAFT_FULL_PACKAGE = CachedPackage.combine(MINECRAFT_PREFIX_PACKAGE, packageVersion);
+						} else {
+							// Assume they're the same instead
+							MINECRAFT_PREFIX_PACKAGE = MINECRAFT_FULL_PACKAGE;
+						}
+
+						// The package is usualy flat, so go with that assumption
+						String matcher =
+								(MINECRAFT_PREFIX_PACKAGE.length() > 0 ? Pattern.quote(MINECRAFT_PREFIX_PACKAGE + ".") : "") + CANONICAL_REGEX;
+
+						// We'll still accept the default location, however
+						setDynamicPackageMatcher("(" + matcher + ")|(" + MINECRAFT_OBJECT + ")");
+
+					} else {
+						// Use the standard matcher
+						setDynamicPackageMatcher(MINECRAFT_OBJECT);
+					}
 				}
 
 				return MINECRAFT_FULL_PACKAGE;
@@ -580,7 +585,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getEntityPlayerClass() {
 		try {
-			return getMinecraftClass("EntityPlayer");
+			return getMinecraftClass("server.level.EntityPlayer","EntityPlayer");
 		} catch (RuntimeException e) {
 			try {
 				// Grab CraftPlayer's handle
@@ -637,7 +642,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getEntityClass() {
 		try {
-			return getMinecraftClass("Entity");
+			return getMinecraftClass("server.world.Entity", "Entity");
 		} catch (RuntimeException e) {
 			return fallbackMethodReturn("Entity", "entity.CraftEntity", "getHandle");
 		}
@@ -657,7 +662,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getWorldServerClass() {
 		try {
-			return getMinecraftClass("WorldServer");
+			return getMinecraftClass("server.level.WorldServer", "WorldServer");
 		} catch (RuntimeException e) {
 			return fallbackMethodReturn("WorldServer", "CraftWorld", "getHandle");
 		}
@@ -669,7 +674,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getNmsWorldClass() {
 		try {
-			return getMinecraftClass("World");
+			return getMinecraftClass("world.level.World", "World");
 		} catch (RuntimeException e) {
 			return setMinecraftClass("World", getWorldServerClass().getSuperclass());
 		}
@@ -696,7 +701,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getPacketClass() {
 		try {
-			return getMinecraftClass("Packet");
+			return getMinecraftClass("network.protocol.Packet", "Packet");
 		} catch (RuntimeException e) {
 			FuzzyClassContract paketContract = null;
 
@@ -752,8 +757,10 @@ public class MinecraftReflection {
 	 * @return The Enum protocol class.
 	 */
 	public static Class<?> getEnumProtocolClass() {
-		try {
-			return getMinecraftClass("EnumProtocol");
+		return getMinecraftClass("network.EnumProtocol", "EnumProtocol");
+
+		/* try {
+			return getMinecraftClass("network.EnumProtocol", "EnumProtocol");
 		} catch (RuntimeException e) {
 			Method protocolMethod = FuzzyReflection.fromClass(getNetworkManagerClass()).getMethod(
 					FuzzyMethodContract.newBuilder().
@@ -762,7 +769,7 @@ public class MinecraftReflection {
 					build()
 			);
 			return setMinecraftClass("EnumProtocol", protocolMethod.getParameterTypes()[0]);
-		}
+		} */
 	}
 
 	/**
@@ -771,7 +778,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getIChatBaseComponentClass() {
 		try {
-			return getMinecraftClass("IChatBaseComponent");
+			return getMinecraftClass("network.chat.IChatbaseComponent", "IChatBaseComponent");
 		} catch (RuntimeException e) {
 			return setMinecraftClass("IChatBaseComponent",
 				Accessors.getMethodAccessor(getCraftChatMessage(), "fromString", String.class).
@@ -790,7 +797,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getChatComponentTextClass() {
 		try {
-			return getMinecraftClass("ChatComponentText");
+			return getMinecraftClass("network.chat.ChatComponentText", "ChatComponentText");
 		} catch (RuntimeException e) {
 			try {
 				Method getScoreboardDisplayName = FuzzyReflection.fromClass(getEntityClass()).
@@ -818,7 +825,8 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getChatSerializerClass() {
 		try {
-			return getMinecraftClass("ChatSerializer", "IChatBaseComponent$ChatSerializer");
+			return getMinecraftClass("network.chat.IChatBaseComponent$ChatSerializer",
+					"ChatSerializer", "IChatBaseComponent$ChatSerializer");
 		} catch (RuntimeException e) {
 			// TODO: Figure out a functional fallback
 			throw new IllegalStateException("Could not find ChatSerializer class.", e);
@@ -830,11 +838,8 @@ public class MinecraftReflection {
 	 * @return The ServerPing class.
 	 */
 	public static Class<?> getServerPingClass() {
-		if (!isUsingNetty())
-			throw new IllegalStateException("ServerPing is only supported in 1.7.2.");
-
 		try {
-			return getMinecraftClass("ServerPing");
+			return getMinecraftClass("network.protocol.status.ServerPing", "ServerPing");
 		} catch (RuntimeException e) {
 			Class<?> statusServerInfo = PacketType.Status.Server.SERVER_INFO.getPacketClass();
 
@@ -856,11 +861,9 @@ public class MinecraftReflection {
 	 * @return The ServerPingServerData class.
 	 */
 	public static Class<?> getServerPingServerDataClass() {
-		if (!isUsingNetty())
-			throw new IllegalStateException("ServerPingServerData is only supported in 1.7.2.");
-
 		try {
-			return getMinecraftClass("ServerPingServerData", "ServerPing$ServerData");
+			return getMinecraftClass("network.protocol.status.ServerPing$ServerData",
+					"ServerPingServerData", "ServerPing$ServerData");
 		} catch (RuntimeException e) {
 			FuzzyReflection fuzzy = FuzzyReflection.fromClass(getServerPingClass(), true);
 			return setMinecraftClass("ServerPingServerData", fuzzy.getFieldByType("(.*)(ServerData)(.*)").getType());
@@ -872,11 +875,9 @@ public class MinecraftReflection {
 	 * @return The ServerPingPlayerSample class.
 	 */
 	public static Class<?> getServerPingPlayerSampleClass() {
-		if (!isUsingNetty())
-			throw new IllegalStateException("ServerPingPlayerSample is only supported in 1.7.2.");
-
 		try {
-			return getMinecraftClass("ServerPingPlayerSample", "ServerPing$ServerPingPlayerSample");
+			return getMinecraftClass("network.protocol.status.ServerPing$ServerPingPlayerSample",
+					"ServerPingPlayerSample", "ServerPing$ServerPingPlayerSample");
 		} catch (RuntimeException e) {
 			Class<?> serverPing = getServerPingClass();
 
@@ -942,7 +943,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getMinecraftServerClass() {
 		try {
-			return getMinecraftClass("MinecraftServer");
+			return getMinecraftClass("server.MinecraftServer","MinecraftServer");
 		} catch (RuntimeException e) {
 			useFallbackServer();
 
@@ -958,7 +959,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getStatisticClass() {
 		// TODO: Implement fallback
-		return getMinecraftClass("Statistic");
+		return getMinecraftClass("stats.Statistic", "Statistic");
 	}
 
 	/**
@@ -967,7 +968,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getStatisticListClass() {
 		// TODO: Implement fallback
-		return getMinecraftClass("StatisticList");
+		return getMinecraftClass("stats.StatisticList", "StatisticList");
 	}
 
 	/**
@@ -994,7 +995,8 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getPlayerListClass() {
 		try {
-			return getMinecraftClass("ServerConfigurationManager", "PlayerList");
+			return getMinecraftClass("server.players.PlayerList",
+					"ServerConfigurationManager", "PlayerList");
 		} catch (RuntimeException e) {
 			useFallbackServer();
 
@@ -1033,7 +1035,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getPlayerConnectionClass() {
 		try  {
-			return getMinecraftClass("PlayerConnection", "NetServerHandler");
+			return getMinecraftClass("server.network.PlayerConnection","PlayerConnection", "NetServerHandler");
 		} catch (RuntimeException e) {
 			try {
 				// Use the player connection field
@@ -1077,7 +1079,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getNetworkManagerClass() {
 		try {
-			return getMinecraftClass("INetworkManager", "NetworkManager");
+			return getMinecraftClass("network.NetworkManager", "INetworkManager", "NetworkManager");
 		} catch (RuntimeException e) {
 			Constructor<?> selected = FuzzyReflection.fromClass(getPlayerConnectionClass()).
 					getConstructor(FuzzyMethodContract.newBuilder().
@@ -1110,7 +1112,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getItemStackClass() {
 		try {
-			return getMinecraftClass("ItemStack");
+			return getMinecraftClass("world.item.ItemStack", "ItemStack");
 		} catch (RuntimeException e) {
 			// Use the handle reference
 			return setMinecraftClass("ItemStack",
@@ -1124,7 +1126,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getBlockClass() {
 		try {
-			return getMinecraftClass("Block");
+			return getMinecraftClass("world.level.block.Block", "Block");
 		} catch (RuntimeException e) {
 			FuzzyReflection reflect = FuzzyReflection.fromClass(getItemStackClass());
 			Set<Class<?>> candidates = new HashSet<Class<?>>();
@@ -1149,15 +1151,15 @@ public class MinecraftReflection {
 	}
 
 	public static Class<?> getItemClass() {
-		return getNullableNMS("Item");
+		return getNullableNMS("world.item.Item", "Item");
 	}
 
 	public static Class<?> getFluidTypeClass() {
-		return getNullableNMS("FluidType");
+		return getNullableNMS("world.level.material.FluidType", "FluidType");
 	}
 
 	public static Class<?> getParticleTypeClass() {
-		return getNullableNMS("ParticleType");
+		return getNullableNMS("core.particles.ParticleType", "ParticleType");
 	}
 
 	/**
@@ -1188,7 +1190,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getDataWatcherClass() {
 		try {
-			return getMinecraftClass("DataWatcher");
+			return getMinecraftClass("network.syncher.DataWatcher", "DataWatcher");
 		} catch (RuntimeException e) {
 			// Describe the DataWatcher
 			FuzzyClassContract dataWatcherContract = FuzzyClassContract.newBuilder().
@@ -1236,7 +1238,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getBlockPositionClass() {
 		try {
-			return getMinecraftClass("BlockPosition");
+			return getMinecraftClass("core.BlockPosition", "BlockPosition");
 		} catch (RuntimeException e) {
 			try {
 				Class<?> normalChunkGenerator = getCraftBukkitClass("generator.NormalChunkGenerator");
@@ -1263,7 +1265,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getVec3DClass() {
 		try {
-			return getMinecraftClass("Vec3D");
+			return getMinecraftClass("world.phys.Vec3D", "Vec3D");
 		} catch (RuntimeException e) {
 			// TODO: Figure out a fuzzy field contract
 			return null;
@@ -1288,13 +1290,10 @@ public class MinecraftReflection {
 	 * @return The ChunkCoordIntPair class.
 	 */
 	public static Class<?> getChunkCoordIntPair() {
-		if (!isUsingNetty())
-			throw new IllegalArgumentException("Not supported on 1.6.4 and older.");
-
 		try {
-			return getMinecraftClass("ChunkCoordIntPair");
+			return getMinecraftClass("world.level.ChunkCoordIntPair", "ChunkCoordIntPair");
 		} catch (RuntimeException e) {
-			Class<?> packet = PacketRegistry.getPacketClassFromType(PacketType.Play.Server.MULTI_BLOCK_CHANGE);
+			Class<?> packet = PacketType.Play.Server.MULTI_BLOCK_CHANGE.getPacketClass();
 
 			AbstractFuzzyMatcher<Class<?>> chunkCoordIntContract = FuzzyClassContract.newBuilder().
 					   field(FuzzyFieldContract.newBuilder().
@@ -1326,7 +1325,8 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getDataWatcherItemClass() {
 		try {
-			return getMinecraftClass("DataWatcher$Item", "DataWatcher$WatchableObject", "WatchableObject");
+			return getMinecraftClass("network.syncher.DataWatcher$Item",
+					"DataWatcher$Item", "DataWatcher$WatchableObject", "WatchableObject");
 		} catch (RuntimeException e) {
 			Method selected = FuzzyReflection.fromClass(getDataWatcherClass(), true).
 					getMethod(FuzzyMethodContract.newBuilder().
@@ -1342,7 +1342,7 @@ public class MinecraftReflection {
 
 	public static Class<?> getDataWatcherObjectClass() {
 		try {
-			return getMinecraftClass("DataWatcherObject");
+			return getMinecraftClass("network.syncher.DataWatcherObject", "DataWatcherObject");
 		} catch (RuntimeException ex) {
 			return null;
 		}
@@ -1362,27 +1362,27 @@ public class MinecraftReflection {
 
 	public static Class<?> getDataWatcherSerializerClass() {
 		// TODO Implement a fallback
-		return getNullableNMS("DataWatcherSerializer");
+		return getNullableNMS("network.syncher.DataWatcherSerializer", "DataWatcherSerializer");
 	}
 
 	public static Class<?> getDataWatcherRegistryClass() {
 		// TODO Implement a fallback
-		return getMinecraftClass("DataWatcherRegistry");
+		return getMinecraftClass("network.syncher.DataWatcherRegistry", "DataWatcherRegistry");
 	}
 
 	public static Class<?> getMinecraftKeyClass() {
 		// TODO Implement a fallback
-		return getMinecraftClass("MinecraftKey");
+		return getMinecraftClass("resources.MinecraftKey", "MinecraftKey");
 	}
 
 	public static Class<?> getMobEffectListClass() {
 		// TODO Implement a fallback
-		return getMinecraftClass("MobEffectList");
+		return getMinecraftClass("world.effect.MobEffectList", "MobEffectList");
 	}
 
 	public static Class<?> getSoundEffectClass() {
 		try {
-			return getMinecraftClass("SoundEffect");
+			return getMinecraftClass("sounds.SoundEffect", "SoundEffect");
 		} catch (RuntimeException ex) {
 			FuzzyReflection fuzzy = FuzzyReflection.fromClass(PacketType.Play.Server.NAMED_SOUND_EFFECT.getPacketClass(), true);
 			Field field = fuzzy.getFieldByType("(.*)(Sound)(.*)");
@@ -1396,7 +1396,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getServerConnectionClass() {
 		try {
-			return getMinecraftClass("ServerConnection");
+			return getMinecraftClass("server.network.ServerConnection", "ServerConnection");
 		} catch (RuntimeException e) {
 			Method selected = null;
 			FuzzyClassContract.Builder serverConnectionContract = FuzzyClassContract.newBuilder().
@@ -1441,7 +1441,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getNBTBaseClass() {
 		try {
-			return getMinecraftClass("NBTBase");
+			return getMinecraftClass("nbt.NBTBase", "NBTBase");
 		} catch (RuntimeException e) {
 			Class<?> nbtBase = null;
 
@@ -1501,7 +1501,7 @@ public class MinecraftReflection {
 	 * @return The NBT read limiter.
 	 */
 	public static Class<?> getNBTReadLimiterClass() {
-		return getMinecraftClass("NBTReadLimiter");
+		return getMinecraftClass("nbt.NBTReadLimiter", "NBTReadLimiter");
 	}
 
 	/**
@@ -1510,7 +1510,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getNBTCompoundClass() {
 		try {
-			return getMinecraftClass("NBTTagCompound");
+			return getMinecraftClass("nbt.NBTTagCompound","NBTTagCompound");
 		} catch (RuntimeException e) {
 			return setMinecraftClass(
 				"NBTTagCompound",
@@ -1525,7 +1525,8 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getEntityTrackerClass() {
 		try {
-			return getMinecraftClass("EntityTracker", "PlayerChunkMap$EntityTracker");
+			return getMinecraftClass("server.level.PlayerChunkMap$EntityTracker",
+					"EntityTracker", "PlayerChunkMap$EntityTracker");
 		} catch (RuntimeException e) {
 			FuzzyClassContract entityTrackerContract = FuzzyClassContract.newBuilder().
 					field(FuzzyFieldContract.newBuilder().
@@ -1553,38 +1554,6 @@ public class MinecraftReflection {
 		}
 	}
 
-	/**
-	 * Retrieve the NetworkListenThread class (NMS).
-	 * <p>
-	 * Note that this class was removed after Minecraft 1.3.1.
-	 * @return NetworkListenThread class.
-	 */
-	public static Class<?> getNetworkListenThreadClass() {
-		try {
-			return getMinecraftClass("NetworkListenThread");
-		} catch (RuntimeException e) {
-			FuzzyClassContract networkListenContract = FuzzyClassContract.newBuilder().
-					field(FuzzyFieldContract.newBuilder().
-						  typeDerivedOf(ServerSocket.class)).
-					field(FuzzyFieldContract.newBuilder().
-						  typeDerivedOf(Thread.class)).
-					field(FuzzyFieldContract.newBuilder().
-						  typeDerivedOf(List.class)).
-					method(FuzzyMethodContract.newBuilder().
-						  parameterExactType(getPlayerConnectionClass())).
-			build();
-
-			Field selected = FuzzyReflection.fromClass(MinecraftReflection.getMinecraftServerClass(), true).
-					getField(FuzzyFieldContract.newBuilder().
-							   typeMatches(networkListenContract).
-							   build()
-					);
-
-			// Go by the defined type of this field
-			return setMinecraftClass("NetworkListenThread", selected.getType());
-		}
-	}
-
 	/**
 	 * Retrieve the attribute snapshot class.
 	 * <p>
@@ -1593,7 +1562,8 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getAttributeSnapshotClass() {
 		try {
-			return getMinecraftClass("AttributeSnapshot", "PacketPlayOutUpdateAttributes$AttributeSnapshot");
+			return getMinecraftClass("network.protocol.game.PacketPlayOutUpdateAttributes$AttributeSnapshot",
+					"AttributeSnapshot", "PacketPlayOutUpdateAttributes$AttributeSnapshot");
 		} catch (RuntimeException ex) {
 			try {
 				// It should be the parameter of a list in the update attributes packet
@@ -1652,7 +1622,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getAttributeModifierClass() {
 		try {
-			return getMinecraftClass("AttributeModifier");
+			return getMinecraftClass("world.entity.ai.attributes.AttributeModifier", "AttributeModifier");
 		} catch (RuntimeException e) {
 			getAttributeSnapshotClass();
 
@@ -1668,10 +1638,10 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getMobEffectClass() {
 		try {
-			return getMinecraftClass("MobEffect");
+			return getMinecraftClass("world.effect.MobEffect", "MobEffect");
 		} catch (RuntimeException e) {
 			// It is the second parameter in Packet41MobEffect
-			Class<?> packet = PacketRegistry.getPacketClassFromType(PacketType.Play.Server.ENTITY_EFFECT);
+			Class<?> packet = PacketType.Play.Server.ENTITY_EFFECT.getPacketClass();
 			Constructor<?> constructor = FuzzyReflection.fromClass(packet).getConstructor(
 				FuzzyMethodContract.newBuilder().
 				parameterCount(2).
@@ -1689,7 +1659,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getPacketDataSerializerClass() {
 		try {
-			return getMinecraftClass("PacketDataSerializer");
+			return getMinecraftClass("network.PacketDataSerializer", "PacketDataSerializer");
 		} catch (RuntimeException e) {
 			Class<?> packet = getPacketClass();
 			Method method = FuzzyReflection.fromClass(packet).getMethod(
@@ -1709,7 +1679,7 @@ public class MinecraftReflection {
 	 */
 	public static Class<?> getNbtCompressedStreamToolsClass() {
 		try {
-			return getMinecraftClass("NBTCompressedStreamTools");
+			return getMinecraftClass("nbt.NBTCompressedStreamTools", "NBTCompressedStreamTools");
 		} catch (RuntimeException e) {
 			Class<?> packetSerializer = getPacketDataSerializerClass();
 
@@ -1738,7 +1708,7 @@ public class MinecraftReflection {
 	 * @return The tile entity class.
 	 */
 	public static Class<?> getTileEntityClass() {
-		return getMinecraftClass("TileEntity");
+		return getMinecraftClass("world.level.block.entity.TileEntity", "TileEntity");
 	}
 
 	/**
@@ -1820,7 +1790,54 @@ public class MinecraftReflection {
 	 * @return The PlayerInfoData class
 	 */
 	public static Class<?> getPlayerInfoDataClass() {
-		return getMinecraftClass("PacketPlayOutPlayerInfo$PlayerInfoData", "PlayerInfoData");
+		return getMinecraftClass("network.protocol.game.PacketPlayOutPlayerInfo$PlayerInfoData",
+				"PacketPlayOutPlayerInfo$PlayerInfoData", "PlayerInfoData");
+	}
+
+	/**
+	 * Retrieves the entity use action class in 1.17.
+	 * @return The EntityUseAction class
+	 */
+	public static Class<?> getEnumEntityUseActionClass() {
+		Class<?> packetClass = PacketType.Play.Client.USE_ENTITY.getPacketClass();
+		return FuzzyReflection.fromClass(packetClass, true).getFieldByType("^.*(EnumEntityUseAction)").getType();
+	}
+
+	/**
+	 * Get a method accessor to get the actual use action out of the wrapping EnumEntityUseAction in 1.17.
+	 * @return a method accessor to get the actual use action
+	 */
+	public static MethodAccessor getEntityUseActionEnumMethodAccessor() {
+		FuzzyReflection fuzzy = FuzzyReflection.fromClass(MinecraftReflection.getEnumEntityUseActionClass(), true);
+		return Accessors.getMethodAccessor(fuzzy.getMethod(FuzzyMethodContract.newBuilder()
+				.returnTypeExact(EnumWrappers.getEntityUseActionClass())
+				.build()));
+	}
+
+	/**
+	 * Get a field accessor for the hand in the wrapping EnumEntityUseAction in 1.17.
+	 *
+	 * @param enumEntityUseAction the object instance of the action, the field is not present in attack.
+	 * @return a field accessor for the hand in the wrapping EnumEntityUseAction
+	 */
+	public static FieldAccessor getHandEntityUseActionEnumFieldAccessor(Object enumEntityUseAction) {
+		FuzzyReflection fuzzy = FuzzyReflection.fromObject(enumEntityUseAction, true);
+		return Accessors.getFieldAccessor(fuzzy.getField(FuzzyFieldContract.newBuilder()
+				.typeExact(EnumWrappers.getHandClass())
+				.build()));
+	}
+
+	/**
+	 * Get a field accessor for the vec3d in the wrapping EnumEntityUseAction in 1.17.
+	 *
+	 * @param enumEntityUseAction the object instance of the action, the field is not present in attack.
+	 * @return a field accessor for the hand in the wrapping EnumEntityUseAction
+	 */
+	public static FieldAccessor getVec3EntityUseActionEnumFieldAccessor(Object enumEntityUseAction) {
+		FuzzyReflection fuzzy = FuzzyReflection.fromObject(enumEntityUseAction, true);
+		return Accessors.getFieldAccessor(fuzzy.getField(FuzzyFieldContract.newBuilder()
+				.typeExact(MinecraftReflection.getVec3DClass())
+				.build()));
 	}
 
 	/**
@@ -1837,7 +1854,7 @@ public class MinecraftReflection {
 	 * @return The IBlockData class
 	 */
 	public static Class<?> getIBlockDataClass() {
-		return getMinecraftClass("IBlockData");
+		return getMinecraftClass("world.level.block.state.IBlockData", "IBlockData");
 	}
 
 	/**
@@ -1856,16 +1873,35 @@ public class MinecraftReflection {
 		return getArrayClass(getMultiBlockChangeInfoClass());
 	}
 
+	/**
+	 * Retrieve the PacketPlayOutGameStateChange.a class, aka GameState in 1.16
+	 * @return The GameState class
+	 */
+	public static Class<?> getGameStateClass() {
+		// it's called "a" so there's not a whole lot we can do to identify it
+		Class<?> packetClass = PacketType.Play.Server.GAME_STATE_CHANGE.getPacketClass();
+		return packetClass.getClasses()[0];
+	}
+
 	public static boolean signUpdateExists() {
-		try {
-			return getMinecraftClass("PacketPlayOutUpdateSign") != null;
-		} catch (RuntimeException ex) {
-			return false;
-		}
+		return getNullableNMS("PacketPlayOutUpdateSign") != null;
 	}
 
 	public static Class<?> getNonNullListClass() {
-		return getMinecraftClass("NonNullList");
+		return getMinecraftClass("core.NonNullList", "NonNullList");
+	}
+
+	public static MethodAccessor getNonNullListCreateAccessor() {
+		try {
+			Class<?> nonNullListType = MinecraftReflection.getNonNullListClass();
+			return Accessors.getMethodAccessor(FuzzyReflection.fromClass(nonNullListType).getMethod(
+					FuzzyMethodContract.newBuilder()
+							.returnTypeExact(nonNullListType)
+							.requireModifier(Modifier.STATIC)
+							.build()));
+		} catch (Exception ex) {
+			return null;
+		}
 	}
 
 	public static Class<?> getCraftSoundClass() {
@@ -1873,7 +1909,7 @@ public class MinecraftReflection {
 	}
 
 	public static Class<?> getSectionPositionClass() {
-		return getMinecraftClass("SectionPosition");
+		return getMinecraftClass("core.SectionPosition", "SectionPosition");
 	}
 
 	// ---- ItemStack conversions
@@ -2027,10 +2063,12 @@ public class MinecraftReflection {
 				.orElseThrow(() -> new RuntimeException("Failed to find NMS class: " + className));
 	}
 
-	public static Class<?> getNullableNMS(String className) {
-		if (minecraftPackage == null)
-			minecraftPackage = new CachedPackage(getMinecraftPackage(), getClassSource());
-		return minecraftPackage.getPackageClass(className).orElse(null);
+	public static Class<?> getNullableNMS(String className, String... aliases) {
+		try {
+			return getMinecraftClass(className, aliases);
+		} catch (RuntimeException ex) {
+			return null;
+		}
 	}
 
 	/**
@@ -2163,4 +2201,70 @@ public class MinecraftReflection {
 			throw new RuntimeException("Cannot construct packet serializer.", e);
 		}
 	}
+
+	public static Class<?> getNbtTagTypes() {
+		return getMinecraftClass("nbt.NBTTagTypes", "NBTTagTypes");
+	}
+
+	public static Class<?> getChatDeserializer() {
+		return getMinecraftClass("util.ChatDeserializer", "ChatDeserializer");
+	}
+
+	public static Class<?> getDimensionManager() {
+		return getMinecraftClass("world.level.dimension.DimensionManager", "DimensionManager");
+	}
+
+	public static Class<?> getMerchantRecipeList() {
+		return getMinecraftClass("world.item.trading.MerchantRecipeList", "MerchantRecipeList");
+	}
+
+	public static Class<?> getResourceKey() {
+		return getMinecraftClass("resources.ResourceKey", "ResourceKey");
+	}
+
+	public static Class<?> getEntityTypes() {
+		return getMinecraftClass("world.entity.EntityTypes", "EntityTypes");
+	}
+
+	public static Class<?> getParticleParam() {
+		return getMinecraftClass("core.particles.ParticleParam", "ParticleParam");
+	}
+
+	public static Class<?> getSectionPosition() {
+		return getMinecraftClass("core.SectionPosition", "SectionPosition");
+	}
+
+	public static Class<?> getChunkProviderServer() {
+		return getMinecraftClass("server.level.ChunkProviderServer", "ChunkProviderServer");
+	}
+
+	public static Class<?> getPlayerChunkMap() {
+		return getMinecraftClass("server.level.PlayerChunkMap", "PlayerChunkMap");
+	}
+
+	public static Class<?> getIRegistry() {
+		return getNullableNMS("core.IRegistry", "IRegistry");
+	}
+
+	public static Class<?> getAttributeBase() {
+		return getMinecraftClass("world.entity.ai.attributes.AttributeBase", "AttributeBase");
+	}
+
+	public static Class<?> getFastUtilClass(String className) {
+		try {
+			return getMinecraftLibraryClass("it.unimi.dsi.fastutil." + className);
+		} catch (RuntimeException ex) {
+			Class<?> clazz = getMinecraftLibraryClass("org.bukkit.craftbukkit.libs.it.unimi.dsi.fastutil." + className);
+			setMinecraftLibraryClass("it.unimi.dsi.fastutil." + className, clazz);
+			return clazz;
+		}
+	}
+
+	public static Class<?> getInt2ObjectMapClass() {
+		return getFastUtilClass("ints.Int2ObjectMap");
+	}
+
+	public static Class<?> getIntArrayListClass() {
+		return getFastUtilClass("ints.IntArrayList");
+	}
 }

src/main/java/com/comphenix/protocol/utility/MinecraftVersion.java

@@ -44,6 +44,11 @@ public class MinecraftVersion implements Comparable<MinecraftVersion>, Serializa
 	 */
 	private static final Pattern VERSION_PATTERN = Pattern.compile(".*\\(.*MC.\\s*([a-zA-z0-9\\-.]+).*");
 
+	/**
+	 * Version 1.17 - caves and cliffs part 1
+	 */
+	public static final MinecraftVersion CAVES_CLIFFS_1 = new MinecraftVersion("1.17");
+
 	/**
 	 * Version 1.16.2 - breaking change to the nether update
 	 */

src/main/java/com/comphenix/protocol/utility/NettyVersion.java

@@ -0,0 +1,83 @@
+package com.comphenix.protocol.utility;
+
+import com.comphenix.protocol.ProtocolLibrary;
+import io.netty.util.Version;
+
+import java.util.Map;
+
+public class NettyVersion {
+    private final static String NETTY_ARTIFACT_ID = "netty-common";
+    private static NettyVersion version;
+
+    public static NettyVersion getVersion() {
+        if(version == null) {
+            version = detectVersion();
+        }
+        return version;
+    }
+
+    private static NettyVersion detectVersion() {
+        Map<String, Version> nettyArtifacts = Version.identify();
+        Version version = nettyArtifacts.get(NETTY_ARTIFACT_ID);
+        if(version != null) {
+            return new NettyVersion(version.artifactVersion());
+        }
+        return new NettyVersion(null);
+    }
+
+    private boolean valid = false;
+    private int major, minor, revision;
+
+    public NettyVersion(String s) {
+        if(s == null) {
+            return;
+        }
+        String[] split = s.split( "\\.");
+        try {
+            this.major = Integer.parseInt(split[0]);
+            this.minor = Integer.parseInt(split[1]);
+            this.revision = Integer.parseInt(split[2]);
+            this.valid = true;
+        } catch (Throwable t) {
+            ProtocolLibrary.getPlugin().getLogger().warning("Could not detect netty version: '" + s + "'");
+        }
+    }
+
+    @Override
+    public String toString() {
+        if(!valid) {
+            return "(invalid)";
+        }
+        return major + "." + minor + "." + revision;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if(!(obj instanceof NettyVersion)) {
+            return false;
+        }
+        NettyVersion v = (NettyVersion) obj;
+        return v.major == major && v.minor == minor && v.revision == revision;
+    }
+
+    public int getMajor() {
+        return major;
+    }
+
+    public int getMinor() {
+        return minor;
+    }
+
+    public int getRevision() {
+        return revision;
+    }
+
+    public boolean isValid() {
+        return this.valid;
+    }
+
+    public boolean isGreaterThan(int major, int minor, int rev) {
+        return this.major > major || this.minor > minor || this.revision > rev;
+    }
+
+}

src/main/java/com/comphenix/protocol/utility/ZeroBuffer.java

@@ -0,0 +1,741 @@
+package com.comphenix.protocol.utility;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufAllocator;
+import io.netty.buffer.ByteBufProcessor;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.channels.GatheringByteChannel;
+import java.nio.channels.ScatteringByteChannel;
+import java.nio.charset.Charset;
+
+public class ZeroBuffer extends ByteBuf {
+    @Override
+    public int capacity() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf capacity(int i) {
+        return null;
+    }
+
+    @Override
+    public int maxCapacity() {
+        return 0;
+    }
+
+    @Override
+    public ByteBufAllocator alloc() {
+        return null;
+    }
+
+    @Override
+    public ByteOrder order() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf order(ByteOrder byteOrder) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf unwrap() {
+        return null;
+    }
+
+    @Override
+    public boolean isDirect() {
+        return false;
+    }
+
+    @Override
+    public int readerIndex() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf readerIndex(int i) {
+        return null;
+    }
+
+    @Override
+    public int writerIndex() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf writerIndex(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setIndex(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public int readableBytes() {
+        return 0;
+    }
+
+    @Override
+    public int writableBytes() {
+        return 0;
+    }
+
+    @Override
+    public int maxWritableBytes() {
+        return 0;
+    }
+
+    @Override
+    public boolean isReadable() {
+        return false;
+    }
+
+    @Override
+    public boolean isReadable(int i) {
+        return false;
+    }
+
+    @Override
+    public boolean isWritable() {
+        return false;
+    }
+
+    @Override
+    public boolean isWritable(int i) {
+        return false;
+    }
+
+    @Override
+    public ByteBuf clear() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf markReaderIndex() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf resetReaderIndex() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf markWriterIndex() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf resetWriterIndex() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf discardReadBytes() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf discardSomeReadBytes() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf ensureWritable(int i) {
+        return null;
+    }
+
+    @Override
+    public int ensureWritable(int i, boolean b) {
+        return 0;
+    }
+
+    @Override
+    public boolean getBoolean(int i) {
+        return false;
+    }
+
+    @Override
+    public byte getByte(int i) {
+        return 0;
+    }
+
+    @Override
+    public short getUnsignedByte(int i) {
+        return 0;
+    }
+
+    @Override
+    public short getShort(int i) {
+        return 0;
+    }
+
+    @Override
+    public int getUnsignedShort(int i) {
+        return 0;
+    }
+
+    @Override
+    public int getMedium(int i) {
+        return 0;
+    }
+
+    @Override
+    public int getUnsignedMedium(int i) {
+        return 0;
+    }
+
+    @Override
+    public int getInt(int i) {
+        return 0;
+    }
+
+    @Override
+    public long getUnsignedInt(int i) {
+        return 0;
+    }
+
+    @Override
+    public long getLong(int i) {
+        return 0;
+    }
+
+    @Override
+    public char getChar(int i) {
+        return 0;
+    }
+
+    @Override
+    public float getFloat(int i) {
+        return 0;
+    }
+
+    @Override
+    public double getDouble(int i) {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, ByteBuf byteBuf) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, ByteBuf byteBuf, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, ByteBuf byteBuf, int i1, int i2) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, byte[] bytes) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, byte[] bytes, int i1, int i2) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, ByteBuffer byteBuffer) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf getBytes(int i, OutputStream outputStream, int i1) throws IOException {
+        return null;
+    }
+
+    @Override
+    public int getBytes(int i, GatheringByteChannel gatheringByteChannel, int i1) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf setBoolean(int i, boolean b) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setByte(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setShort(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setMedium(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setInt(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setLong(int i, long l) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setChar(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setFloat(int i, float v) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setDouble(int i, double v) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, ByteBuf byteBuf) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, ByteBuf byteBuf, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, ByteBuf byteBuf, int i1, int i2) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, byte[] bytes) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, byte[] bytes, int i1, int i2) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf setBytes(int i, ByteBuffer byteBuffer) {
+        return null;
+    }
+
+    @Override
+    public int setBytes(int i, InputStream inputStream, int i1) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public int setBytes(int i, ScatteringByteChannel scatteringByteChannel, int i1) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf setZero(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public boolean readBoolean() {
+        return false;
+    }
+
+    @Override
+    public byte readByte() {
+        return 0;
+    }
+
+    @Override
+    public short readUnsignedByte() {
+        return 0;
+    }
+
+    @Override
+    public short readShort() {
+        return 0;
+    }
+
+    @Override
+    public int readUnsignedShort() {
+        return 0;
+    }
+
+    @Override
+    public int readMedium() {
+        return 0;
+    }
+
+    @Override
+    public int readUnsignedMedium() {
+        return 0;
+    }
+
+    @Override
+    public int readInt() {
+        return 0;
+    }
+
+    @Override
+    public long readUnsignedInt() {
+        return 0;
+    }
+
+    @Override
+    public long readLong() {
+        return 0;
+    }
+
+    @Override
+    public char readChar() {
+        return 0;
+    }
+
+    @Override
+    public float readFloat() {
+        return 0;
+    }
+
+    @Override
+    public double readDouble() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf readBytes(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readSlice(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(ByteBuf byteBuf) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(ByteBuf byteBuf, int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(ByteBuf byteBuf, int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(byte[] bytes) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(byte[] bytes, int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(ByteBuffer byteBuffer) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf readBytes(OutputStream outputStream, int i) throws IOException {
+        return null;
+    }
+
+    @Override
+    public int readBytes(GatheringByteChannel gatheringByteChannel, int i) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf skipBytes(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBoolean(boolean b) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeByte(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeShort(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeMedium(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeInt(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeLong(long l) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeChar(int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeFloat(float v) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeDouble(double v) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(ByteBuf byteBuf) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(ByteBuf byteBuf, int i) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(ByteBuf byteBuf, int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(byte[] bytes) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(byte[] bytes, int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf writeBytes(ByteBuffer byteBuffer) {
+        return null;
+    }
+
+    @Override
+    public int writeBytes(InputStream inputStream, int i) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public int writeBytes(ScatteringByteChannel scatteringByteChannel, int i) throws IOException {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf writeZero(int i) {
+        return null;
+    }
+
+    @Override
+    public int indexOf(int i, int i1, byte b) {
+        return 0;
+    }
+
+    @Override
+    public int bytesBefore(byte b) {
+        return 0;
+    }
+
+    @Override
+    public int bytesBefore(int i, byte b) {
+        return 0;
+    }
+
+    @Override
+    public int bytesBefore(int i, int i1, byte b) {
+        return 0;
+    }
+
+    @Override
+    public int forEachByte(ByteBufProcessor byteBufProcessor) {
+        return 0;
+    }
+
+    @Override
+    public int forEachByte(int i, int i1, ByteBufProcessor byteBufProcessor) {
+        return 0;
+    }
+
+    @Override
+    public int forEachByteDesc(ByteBufProcessor byteBufProcessor) {
+        return 0;
+    }
+
+    @Override
+    public int forEachByteDesc(int i, int i1, ByteBufProcessor byteBufProcessor) {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf copy() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf copy(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf slice() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf slice(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuf duplicate() {
+        return null;
+    }
+
+    @Override
+    public int nioBufferCount() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuffer nioBuffer() {
+        return null;
+    }
+
+    @Override
+    public ByteBuffer nioBuffer(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuffer internalNioBuffer(int i, int i1) {
+        return null;
+    }
+
+    @Override
+    public ByteBuffer[] nioBuffers() {
+        return new ByteBuffer[0];
+    }
+
+    @Override
+    public ByteBuffer[] nioBuffers(int i, int i1) {
+        return new ByteBuffer[0];
+    }
+
+    @Override
+    public boolean hasArray() {
+        return false;
+    }
+
+    @Override
+    public byte[] array() {
+        return new byte[0];
+    }
+
+    @Override
+    public int arrayOffset() {
+        return 0;
+    }
+
+    @Override
+    public boolean hasMemoryAddress() {
+        return false;
+    }
+
+    @Override
+    public long memoryAddress() {
+        return 0;
+    }
+
+    @Override
+    public String toString(Charset charset) {
+        return "";
+    }
+
+    @Override
+    public String toString(int i, int i1, Charset charset) {
+        return "";
+    }
+
+    @Override
+    public int hashCode() {
+        return 0;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        return false;
+    }
+
+    @Override
+    public int compareTo(ByteBuf byteBuf) {
+        return 0;
+    }
+
+    @Override
+    public String toString() {
+        return null;
+    }
+
+    @Override
+    public ByteBuf retain(int i) {
+        return null;
+    }
+
+    @Override
+    public boolean release() {
+        return false;
+    }
+
+    @Override
+    public boolean release(int i) {
+        return false;
+    }
+
+    @Override
+    public int refCnt() {
+        return 0;
+    }
+
+    @Override
+    public ByteBuf retain() {
+        return null;
+    }
+}

src/main/java/com/comphenix/protocol/wrappers/AdventureComponentConverter.java

@@ -0,0 +1,57 @@
+/**
+ *  ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
+ *  Copyright (C) 2015 dmulloy2
+ *
+ *  This program is free software; you can redistribute it and/or modify it under the terms of the
+ *  GNU General Public License as published by the Free Software Foundation; either version 2 of
+ *  the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with this program;
+ *  if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ *  02111-1307 USA
+ */
+package com.comphenix.protocol.wrappers;
+
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
+
+/**
+ * Utility class for converting between the Adventure API Component and ProtocolLib's wrapper
+ * <p>
+ * Note: The Adventure API Component is not included in CraftBukkit, Bukkit or Spigot and but is present in PaperMC.
+ */
+public class AdventureComponentConverter {
+	
+	private AdventureComponentConverter() {
+	}
+
+	/**
+	 * Converts a {@link WrappedChatComponent} into a {@link Component}
+	 * @param wrapper ProtocolLib wrapper
+	 * @return Component
+	 */
+  	public static Component fromWrapper(WrappedChatComponent wrapper) {
+    		return GsonComponentSerializer.gson().deserialize(wrapper.getJson());
+ 	}
+
+ 	/**
+	 * Converts a {@link Component} into a ProtocolLib wrapper
+	 * @param components Component
+	 * @return ProtocolLib wrapper
+	 */
+  	public static WrappedChatComponent fromComponent(Component component) {
+    		return WrappedChatComponent.fromJson(GsonComponentSerializer.gson().serialize(component));
+  	}
+
+  	public static Class<?> getComponentClass() {
+    		return Component.class;
+  	}
+
+  	public static Component clone(Object component) {
+		return (Component) component;
+  	}
+}

src/main/java/com/comphenix/protocol/wrappers/BukkitConverters.java

@@ -17,12 +17,16 @@
 package com.comphenix.protocol.wrappers;
 
 import java.lang.ref.WeakReference;
-import java.lang.reflect.Array;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.Method;
-import java.lang.reflect.Modifier;
-import java.util.*;
+import java.lang.reflect.*;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
@@ -42,6 +46,7 @@ import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 import com.comphenix.protocol.reflect.accessors.MethodAccessor;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
@@ -49,12 +54,17 @@ import com.comphenix.protocol.wrappers.EnumWrappers.Dimension;
 import com.comphenix.protocol.wrappers.EnumWrappers.FauxEnumConverter;
 import com.comphenix.protocol.wrappers.nbt.NbtBase;
 import com.comphenix.protocol.wrappers.nbt.NbtFactory;
+
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 
-import org.bukkit.*;
+import org.bukkit.Bukkit;
+import org.bukkit.Material;
+import org.bukkit.Sound;
+import org.bukkit.World;
+import org.bukkit.WorldType;
 import org.bukkit.advancement.Advancement;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
@@ -257,6 +267,87 @@ public class BukkitConverters {
 		};
 	}
 
+	private static final Map<Class<?>, Supplier<List<Object>>> LIST_SUPPLIERS = new ConcurrentHashMap<>();
+
+	private static <T> Object getGenericList(Class<?> listClass, List<T> specific, EquivalentConverter<T> itemConverter) {
+		List<Object> newList;
+		Supplier<List<Object>> supplier = LIST_SUPPLIERS.get(listClass);
+		if (supplier == null) {
+			try {
+				Constructor<?> ctor = listClass.getConstructor();
+				newList = (List<Object>) ctor.newInstance();
+				supplier = () -> {
+					try {
+						return (List<Object>) ctor.newInstance();
+					} catch (ReflectiveOperationException ex) {
+						throw new RuntimeException(ex);
+					}
+				};
+			} catch (ReflectiveOperationException ex) {
+				ex.printStackTrace();
+				supplier = ArrayList::new;
+				newList = new ArrayList<>();
+			}
+
+			LIST_SUPPLIERS.put(listClass, supplier);
+		} else {
+			newList = supplier.get();
+		}
+
+		// Convert each object
+		for (T position : specific) {
+			if (position != null) {
+				Object converted = itemConverter.getGeneric(position);
+				if (converted != null) {
+					newList.add(converted);
+				}
+			} else {
+				newList.add(null);
+			}
+		}
+
+		return newList;
+	}
+
+	private static <T> List<T> getSpecificList(Object generic, EquivalentConverter<T> itemConverter) {
+		if (generic instanceof Collection) {
+			List<T> items = new ArrayList<>();
+
+			// Copy everything to a new list
+			for (Object item : (Collection<Object>) generic) {
+				T result = itemConverter.getSpecific(item);
+
+				if (item != null)
+					items.add(result);
+			}
+			return items;
+		}
+
+		// Not valid
+		return null;
+	}
+
+	public static <T> EquivalentConverter<List<T>> getListConverter(final Class<?> listClass, final EquivalentConverter<T> itemConverter) {
+		return ignoreNull(new EquivalentConverter<List<T>>() {
+			@Override
+			public List<T> getSpecific(Object generic) {
+				return getSpecificList(generic, itemConverter);
+			}
+
+			@Override
+			public Object getGeneric(List<T> specific) {
+				return getGenericList(listClass, specific, itemConverter);
+			}
+
+			@Override
+			public Class<List<T>> getSpecificType() {
+				// Damn you Java
+				Class<?> dummy = List.class;
+				return (Class<List<T>>) dummy;
+			}
+		});
+	}
+
 	/**
 	 * Retrieve an equivalent converter for a list of generic items.
 	 * @param <T> Type
@@ -268,46 +359,12 @@ public class BukkitConverters {
 		return ignoreNull(new EquivalentConverter<List<T>>() {
 			@Override
 			public List<T> getSpecific(Object generic) {
-				if (generic instanceof Collection) {
-					List<T> items = new ArrayList<>();
-
-					// Copy everything to a new list
-					for (Object item : (Collection<Object>) generic) {
-						T result = itemConverter.getSpecific(item);
-
-						if (item != null)
-							items.add(result);
-					}
-					return items;
-				}
-
-				// Not valid
-				return null;
+				return getSpecificList(generic, itemConverter);
 			}
 
 			@Override
 			public Object getGeneric(List<T> specific) {
-				List<Object> newList;
-
-				try {
-					newList = (List<Object>) specific.getClass().newInstance();
-				} catch (ReflectiveOperationException ex) {
-					newList = new ArrayList<>();
-				}
-
-				// Convert each object
-				for (T position : specific) {
-					if (position != null) {
-						Object converted = itemConverter.getGeneric(position);
-						if (converted != null) {
-							newList.add(converted);
-						}
-					} else {
-						newList.add(null);
-					}
-				}
-
-				return newList;
+				return getGenericList(specific.getClass(), specific, itemConverter);
 			}
 
 			@Override
@@ -349,20 +406,6 @@ public class BukkitConverters {
 		});
 	}
 
-	/**
-	 * @deprecated While this solution is not as abhorrent as I had imagined, I still highly recommend switching to the
-	 * new conversion API.
-	 */
-	@Deprecated
-	public static <T> EquivalentConverter<Set<T>> getSetConverter(final Class<?> genericType,
-	                                                              final EquivalentConverter<T> itemConverter) {
-		if (itemConverter instanceof EnumWrappers.EnumConverter) {
-			((EnumWrappers.EnumConverter) itemConverter).setGenericType(genericType);
-		}
-
-		return getSetConverter(itemConverter);
-	}
-
 	/**
 	 * Retrieve an equivalent converter for a set of generic items.
 	 * @param <T> Element type
@@ -700,7 +743,7 @@ public class BukkitConverters {
 			@Override
 			public Object getGeneric(EntityType specific) {
 				if (entityTypeFromName == null) {
-					Class<?> entityTypesClass = MinecraftReflection.getMinecraftClass("EntityTypes");
+					Class<?> entityTypesClass = MinecraftReflection.getEntityTypes();
 					entityTypeFromName = Accessors.getMethodAccessor(
 							FuzzyReflection
 									.fromClass(entityTypesClass, false)
@@ -718,7 +761,7 @@ public class BukkitConverters {
 			@Override
 			public EntityType getSpecific(Object generic) {
 				if (getEntityTypeName == null) {
-					Class<?> entityTypesClass = MinecraftReflection.getMinecraftClass("EntityTypes");
+					Class<?> entityTypesClass = MinecraftReflection.getEntityTypes();
 					getEntityTypeName = Accessors.getMethodAccessor(
 							FuzzyReflection
 									.fromClass(entityTypesClass, false)
@@ -1075,7 +1118,7 @@ public class BukkitConverters {
 			public Advancement getSpecific(Object generic) {
 				try {
 					return (Advancement) getCraftBukkitClass("advancement.CraftAdvancement")
-							.getConstructor(getMinecraftClass("Advancement"))
+							.getConstructor(getMinecraftClass("advancements.Advancement", "Advancement"))
 							.newInstance(generic);
 				} catch (ReflectiveOperationException ex) {
 					throw new RuntimeException(ex);
@@ -1194,7 +1237,12 @@ public class BukkitConverters {
 			public Object getGeneric(PotionEffectType specific) {
 				Class<?> clazz = MinecraftReflection.getMobEffectListClass();
 				if (getMobEffect == null) {
-					getMobEffect = Accessors.getMethodAccessor(clazz, "fromId", int.class);
+					FuzzyReflection fuzzy = FuzzyReflection.fromClass(clazz, false);
+					getMobEffect = Accessors.getMethodAccessor(fuzzy.getMethod(FuzzyMethodContract.newBuilder()
+							.parameterExactArray(int.class)
+							.returnTypeExact(clazz)
+							.requireModifier(Modifier.STATIC)
+							.build()));
 				}
 
 				int id = specific.getId();
@@ -1205,7 +1253,12 @@ public class BukkitConverters {
 			public PotionEffectType getSpecific(Object generic) {
 				Class<?> clazz = MinecraftReflection.getMobEffectListClass();
 				if (getMobEffectId == null) {
-					getMobEffectId = Accessors.getMethodAccessor(clazz, "getId", clazz);
+					FuzzyReflection fuzzy = FuzzyReflection.fromClass(clazz, false);
+					getMobEffectId = Accessors.getMethodAccessor(fuzzy.getMethod(FuzzyMethodContract.newBuilder()
+							.parameterExactArray(clazz)
+							.returnTypeExact(int.class)
+							.requireModifier(Modifier.STATIC)
+							.build()));
 				}
 
 				int id = (int) getMobEffectId.invoke(null, generic);
@@ -1234,7 +1287,7 @@ public class BukkitConverters {
 
 				if (worldKeyField == null) {
 					Class<?> worldClass = MinecraftReflection.getNmsWorldClass();
-					Class<?> resourceKeyClass = MinecraftReflection.getMinecraftClass("ResourceKey");
+					Class<?> resourceKeyClass = MinecraftReflection.getResourceKey();
 
 					FuzzyReflection fuzzy = FuzzyReflection.fromClass(nmsWorld.getClass(), true);
 					worldKeyField = Accessors.getFieldAccessor(fuzzy.getParameterizedField(resourceKeyClass, worldClass));
@@ -1294,14 +1347,95 @@ public class BukkitConverters {
 		}
 	}
 
+	private static FieldAccessor dimensionKey;
+	private static MethodAccessor worldHandleAccessor;
+	private static MethodAccessor worldHandleDimensionManagerAccessor;
+
+	public static EquivalentConverter<World> getDimensionConverter() {
+		return ignoreNull(new EquivalentConverter<World>() {
+			@Override
+			public Object getGeneric(World specific) {
+				return getWorldHandleDimensionManagerAccessor().invoke(getWorldHandleAccessor().invoke(specific));
+			}
+
+			@Override
+			public World getSpecific(Object generic) {
+				for (World world : Bukkit.getWorlds()) {
+					if (getGeneric(world) == generic) {
+						return world;
+					}
+				}
+				throw new IllegalArgumentException();
+			}
+
+			@Override
+			public Class<World> getSpecificType() {
+				return World.class;
+			}
+		});
+	}
+
+	private static MethodAccessor getWorldHandleAccessor() {
+		if (worldHandleAccessor == null) {
+			Method handleMethod = FuzzyReflection.fromClass(MinecraftReflection.getCraftWorldClass())
+					.getMethod(FuzzyMethodContract.newBuilder()
+							.nameExact("getHandle") // i guess this will never change
+							.returnTypeExact(MinecraftReflection.getWorldServerClass())
+							.build());
+			worldHandleAccessor = Accessors.getMethodAccessor(handleMethod);
+		}
+		return worldHandleAccessor;
+	}
+
+	private static MethodAccessor getWorldHandleDimensionManagerAccessor() {
+		if (worldHandleDimensionManagerAccessor == null) {
+			Method dimensionGetter = FuzzyReflection.fromClass(MinecraftReflection.getWorldServerClass())
+					.getMethod(FuzzyMethodContract.newBuilder()
+							.returnTypeExact(MinecraftReflection.getDimensionManager())
+							.build());
+			worldHandleDimensionManagerAccessor = Accessors.getMethodAccessor(dimensionGetter);
+		}
+		return worldHandleDimensionManagerAccessor;
+	}
+
 	public static EquivalentConverter<Integer> getDimensionIDConverter() {
 		return ignoreNull(new EquivalentConverter<Integer>() {
 			@Override
 			public Object getGeneric(Integer specific) {
 				if (dimensionManager == null) {
-					dimensionManager = MinecraftReflection.getNullableNMS("DimensionManager");
+					dimensionManager = MinecraftReflection.getDimensionManager();
 				}
 
+				if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+					World world = null;
+					if (specific == 0) {
+						world = Bukkit.getWorlds().get(0);
+					} else if (specific == -1) {
+						for (World world1 : Bukkit.getWorlds()) {
+							if (world1.getEnvironment() == World.Environment.NETHER) {
+								world = world1;
+								break;
+							}
+						}
+					} else if (specific == 1) {
+						for (World world1 : Bukkit.getWorlds()) {
+							if (world1.getEnvironment() == World.Environment.THE_END) {
+								world = world1;
+								break;
+							}
+						}
+					}
+
+					if (world != null) {
+						try {
+							return getWorldHandleDimensionManagerAccessor().invoke(getWorldHandleAccessor().invoke(world));
+						} catch (Exception ignored) {
+							// method not available, fall through
+						}
+					}
+
+					throw new IllegalArgumentException();
+				}
 				if (MinecraftVersion.NETHER_UPDATE_2.atOrAbove()) {
 					if (dimensionImplConverter == null) {
 						dimensionImplConverter = new FauxEnumConverter<>(DimensionImpl.class, dimensionManager);
@@ -1335,9 +1469,31 @@ public class BukkitConverters {
 			@Override
 			public Integer getSpecific(Object generic) {
 				if (dimensionManager == null) {
-					dimensionManager = MinecraftReflection.getNullableNMS("DimensionManager");
+					dimensionManager = MinecraftReflection.getDimensionManager();
 				}
 
+				if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+					if (dimensionKey == null) {
+						FuzzyReflection fuzzy = FuzzyReflection.fromClass(dimensionManager, false);
+						dimensionKey = Accessors.getFieldAccessor(fuzzy.getField(FuzzyFieldContract
+								.newBuilder()
+								.typeExact(MinecraftReflection.getMinecraftKeyClass())
+								.banModifier(Modifier.STATIC)
+								.build()));
+					}
+
+					MinecraftKey key = MinecraftKey.fromHandle(dimensionKey.get(generic));
+					switch (key.getKey()) {
+						case "overworld":
+							return Dimension.OVERWORLD.getId();
+						case "the_nether":
+							return Dimension.THE_NETHER.getId();
+						case "the_end":
+							return Dimension.THE_END.getId();
+						default:
+							throw new IllegalArgumentException("id not supported for extra dimensions");
+					}
+				}
 				if (MinecraftVersion.NETHER_UPDATE_2.atOrAbove()) {
 					if (dimensionImplConverter == null) {
 						dimensionImplConverter = new FauxEnumConverter<>(DimensionImpl.class, dimensionManager);
@@ -1393,7 +1549,7 @@ public class BukkitConverters {
 			@Override
 			public Object getGeneric(List<MerchantRecipe> specific) {
 				if (merchantRecipeListConstructor == null) {
-					Class<?> merchantRecipeListClass = MinecraftReflection.getMinecraftClass("MerchantRecipeList");
+					Class<?> merchantRecipeListClass = MinecraftReflection.getMerchantRecipeList();
 					merchantRecipeListConstructor = Accessors.getConstructorAccessor(merchantRecipeListClass);
 					Class<?> craftMerchantRecipeClass = MinecraftReflection.getCraftBukkitClass("inventory.CraftMerchantRecipe");
 					FuzzyReflection reflection = FuzzyReflection.fromClass(craftMerchantRecipeClass, false);
@@ -1407,7 +1563,9 @@ public class BukkitConverters {
 			@Override
 			public List<MerchantRecipe> getSpecific(Object generic) {
 				if (nmsMerchantRecipeToBukkit == null) {
-					Class<?> merchantRecipeClass = MinecraftReflection.getMinecraftClass("MerchantRecipe");
+					Class<?> merchantRecipeClass = MinecraftReflection.getMinecraftClass(
+							"world.item.trading.MerchantRecipe","MerchantRecipe"
+					);
 					FuzzyReflection reflection = FuzzyReflection.fromClass(merchantRecipeClass, false);
 					nmsMerchantRecipeToBukkit = Accessors.getMethodAccessor(reflection.getMethodByName("asBukkit"));
 				}
@@ -1432,7 +1590,7 @@ public class BukkitConverters {
 			@Override
 			public Object getGeneric(BlockPosition specific) {
 				if (sectionPositionClass == null) {
-					sectionPositionClass = MinecraftReflection.getMinecraftClass("SectionPosition");
+					sectionPositionClass = MinecraftReflection.getSectionPosition();
 				}
 
 				if (sectionPositionCreate == null) {
@@ -1461,4 +1619,73 @@ public class BukkitConverters {
 			}
 		});
 	}
+
+	private static Field gameStateMapField;
+	private static Field gameStateIdField;
+
+	public static EquivalentConverter<Integer> getGameStateConverter() {
+		return new EquivalentConverter<Integer>() {
+			@Override
+			public Object getGeneric(Integer specific) {
+				if (specific == null) {
+					specific = 0;
+				}
+
+				if (MinecraftVersion.NETHER_UPDATE.atOrAbove()) {
+					if (gameStateMapField == null) {
+						Class<?> stateClass = MinecraftReflection.getGameStateClass();
+						gameStateMapField = FuzzyReflection
+								.fromClass(stateClass, true)
+								.getField(FuzzyFieldContract
+										.newBuilder()
+										.typeDerivedOf(Map.class)
+										.build());
+						gameStateMapField.setAccessible(true);
+					}
+
+					try {
+						Map<Integer, Object> map = (Map<Integer, Object>) gameStateMapField.get(null);
+						return map.get(specific);
+					} catch (ReflectiveOperationException ex) {
+						throw new RuntimeException(ex);
+					}
+				} else {
+					return specific;
+				}
+			}
+
+			@Override
+			public Integer getSpecific(Object generic) {
+				if (generic == null) {
+					return 0;
+				}
+
+				if (MinecraftVersion.NETHER_UPDATE.atOrAbove()) {
+					if (gameStateIdField == null) {
+						Class<?> stateClass = MinecraftReflection.getGameStateClass();
+						gameStateIdField = FuzzyReflection
+								.fromClass(stateClass, true)
+								.getField(FuzzyFieldContract
+										.newBuilder()
+										.typeExact(int.class)
+										.build());
+						gameStateIdField.setAccessible(true);
+					}
+
+					try {
+						return (Integer) gameStateIdField.get(generic);
+					} catch (ReflectiveOperationException ex) {
+						throw new RuntimeException(ex);
+					}
+				} else {
+					return (Integer) generic;
+				}
+			}
+
+			@Override
+			public Class<Integer> getSpecificType() {
+				return Integer.class;
+			}
+		};
+	}
 }

src/main/java/com/comphenix/protocol/wrappers/ChunkCoordIntPair.java

@@ -1,12 +1,18 @@
 package com.comphenix.protocol.wrappers;
 
 import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.google.common.base.Objects;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.List;
+
 /**
  * Represents a ChunkCoordIntPair.
  * @author Kristian
@@ -79,9 +85,14 @@ public class ChunkCoordIntPair {
 			public ChunkCoordIntPair getSpecific(Object generic) {
 				if (MinecraftReflection.isChunkCoordIntPair(generic)) {
 					if (COORD_X == null || COORD_Z == null) {
-						FieldAccessor[] ints = Accessors.getFieldAccessorArray(COORD_PAIR_CLASS, int.class, true);
-						COORD_X = ints[0];
-						COORD_Z = ints[1];
+						FuzzyReflection fuzzy = FuzzyReflection.fromClass(COORD_PAIR_CLASS, true);
+						List<Field> fields = fuzzy.getFieldList(FuzzyFieldContract
+								.newBuilder()
+								.banModifier(Modifier.STATIC)
+								.typeExact(int.class)
+								.build());
+						COORD_X = Accessors.getFieldAccessor(fields.get(0));
+						COORD_Z = Accessors.getFieldAccessor(fields.get(1));
 					}
 					return new ChunkCoordIntPair((Integer) COORD_X.get(generic), (Integer) COORD_Z.get(generic));
 				}

src/main/java/com/comphenix/protocol/wrappers/Converters.java

@@ -17,6 +17,7 @@
 package com.comphenix.protocol.wrappers;
 
 import java.lang.reflect.Array;
+import java.util.Optional;
 import java.util.function.Function;
 
 import com.comphenix.protocol.reflect.EquivalentConverter;
@@ -150,4 +151,24 @@ public class Converters {
 			}
 		};
 	}
+
+	public static <T> EquivalentConverter<Optional<T>> optional(final EquivalentConverter<T> converter) {
+		return new EquivalentConverter<Optional<T>>() {
+			@Override
+			public Object getGeneric(Optional<T> specific) {
+				return specific.map(converter::getGeneric);
+			}
+
+			@Override
+			public Optional<T> getSpecific(Object generic) {
+				Optional<Object> optional = (Optional<Object>) generic;
+				return optional.map(converter::getSpecific);
+			}
+
+			@Override
+			public Class<Optional<T>> getSpecificType() {
+				return (Class<Optional<T>>) Optional.empty().getClass();
+			}
+		};
+	}
 }

src/main/java/com/comphenix/protocol/wrappers/EnumWrappers.java

@@ -10,6 +10,7 @@ import com.comphenix.protocol.ProtocolLogger;
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.google.common.collect.Maps;
 
@@ -481,7 +482,6 @@ public abstract class EnumWrappers {
 			DIFFICULTY_CLASS = getEnum(PacketType.Play.Server.LOGIN.getPacketClass(), 1);
 		}
 
-		ENTITY_USE_ACTION_CLASS = getEnum(PacketType.Play.Client.USE_ENTITY.getPacketClass(), 0);
 		GAMEMODE_CLASS = getEnum(PacketType.Play.Server.LOGIN.getPacketClass(), 0);
 		RESOURCE_PACK_STATUS_CLASS = getEnum(PacketType.Play.Client.RESOURCE_PACK_STATUS.getPacketClass(), 0);
 		PLAYER_INFO_ACTION_CLASS = getEnum(PacketType.Play.Server.PLAYER_INFO.getPacketClass(), 0);
@@ -496,21 +496,29 @@ public abstract class EnumWrappers {
 
 		try {
 			// TODO enum names are more stable than their packet associations
-			ITEM_SLOT_CLASS = MinecraftReflection.getMinecraftClass("EnumItemSlot");
+			ITEM_SLOT_CLASS = MinecraftReflection.getMinecraftClass("world.entity.EnumItemSlot", "EnumItemSlot");
 		} catch (Exception ex) {
 			ITEM_SLOT_CLASS = getEnum(PacketType.Play.Server.ENTITY_EQUIPMENT.getPacketClass(), 0);
 		}
 
-		HAND_CLASS = getEnum(PacketType.Play.Client.USE_ENTITY.getPacketClass(), 1);
+		// In 1.17 the hand and use action class is no longer a field in the packet
+		if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+			HAND_CLASS = MinecraftReflection.getMinecraftClass("world.EnumHand");
+			// class is named 'b' in the packet but class order differs in spigot and paper so we can only use the first method's return type (safest way)
+			ENTITY_USE_ACTION_CLASS = MinecraftReflection.getEnumEntityUseActionClass().getMethods()[0].getReturnType();
+		} else {
+			HAND_CLASS = getEnum(PacketType.Play.Client.USE_ENTITY.getPacketClass(), 1);
+			ENTITY_USE_ACTION_CLASS = getEnum(PacketType.Play.Client.USE_ENTITY.getPacketClass(), 0);
+		}
+
 		DIRECTION_CLASS = getEnum(PacketType.Play.Server.SPAWN_ENTITY_PAINTING.getPacketClass(), 0);
 		CHAT_TYPE_CLASS = getEnum(PacketType.Play.Server.CHAT.getPacketClass(), 0);
-		ENTITY_POSE_CLASS = MinecraftReflection.getNullableNMS("EntityPose");
+		ENTITY_POSE_CLASS = MinecraftReflection.getNullableNMS("world.entity.EntityPose", "EntityPose");
 
 		associate(PROTOCOL_CLASS, Protocol.class, getClientCommandConverter());
 		associate(CLIENT_COMMAND_CLASS, ClientCommand.class, getClientCommandConverter());
 		associate(CHAT_VISIBILITY_CLASS, ChatVisibility.class, getChatVisibilityConverter());
 		associate(DIFFICULTY_CLASS, Difficulty.class, getDifficultyConverter());
-		associate(ENTITY_USE_ACTION_CLASS, EntityUseAction.class, getEntityUseActionConverter());
 		associate(GAMEMODE_CLASS, NativeGameMode.class, getGameModeConverter());
 		associate(RESOURCE_PACK_STATUS_CLASS, ResourcePackStatus.class, getResourcePackStatusConverter());
 		associate(PLAYER_INFO_ACTION_CLASS, PlayerInfoAction.class, getPlayerInfoActionConverter());
@@ -523,15 +531,14 @@ public abstract class EnumWrappers {
 		associate(PARTICLE_CLASS, Particle.class, getParticleConverter());
 		associate(SOUND_CATEGORY_CLASS, SoundCategory.class, getSoundCategoryConverter());
 		associate(ITEM_SLOT_CLASS, ItemSlot.class, getItemSlotConverter());
-		associate(HAND_CLASS, Hand.class, getHandConverter());
 		associate(DIRECTION_CLASS, Direction.class, getDirectionConverter());
 		associate(CHAT_TYPE_CLASS, ChatType.class, getChatTypeConverter());
-		
+		associate(HAND_CLASS, Hand.class, getHandConverter());
+		associate(ENTITY_USE_ACTION_CLASS, EntityUseAction.class, getEntityUseActionConverter());
+
 		if (ENTITY_POSE_CLASS != null) {
 			associate(ENTITY_POSE_CLASS, EntityPose.class, getEntityPoseConverter());
 		}
-		
-		INITIALIZED = true;
 	}
 
 	private static void associate(Class<?> nativeClass, Class<?> wrapperClass, EquivalentConverter<?> converter) {
@@ -550,12 +557,19 @@ public abstract class EnumWrappers {
 	 * @return The type of the enum field.
 	 */
 	private static Class<?> getEnum(Class<?> clazz, int index) {
-		try {
-			return FuzzyReflection.fromClass(clazz, true).getFieldListByType(Enum.class).get(index).getType();
-		} catch (Throwable ex) {
-			ProtocolLogger.debug("Exception getting enum from " + clazz + " at index " + index, ex);
+		if (clazz == null) {
+			// not supported in the current version
 			return null;
 		}
+
+		List<Field> enumFields = FuzzyReflection.fromClass(clazz, true).getFieldListByType(Enum.class);
+		if (enumFields.size() <= index) {
+			// also probably not supported
+			ProtocolLogger.debug("Enum field not found at index {0} of {1}", index, clazz);
+			return null;
+		}
+
+		return enumFields.get(index).getType();
 	}
 
 	public static Map<Class<?>, EquivalentConverter<?>> getFromNativeMap() {
@@ -772,22 +786,17 @@ public abstract class EnumWrappers {
 		return new EnumConverter<>(genericClass, specificType);
 	}
 
-	/**
-	 * @deprecated Replaced with {@link #getGenericConverter(Class, Class)}
-	 */
-	@Deprecated
-	public static <T extends Enum<T>> EquivalentConverter<T> getGenericConverter(Class<T> specificType) {
-		return new EnumConverter<>(null, specificType);
-	}
-
 	/**
 	 * The common Enum converter
 	 */
 	public static class EnumConverter<T extends Enum<T>> implements EquivalentConverter<T> {
-		private Class<?> genericType;
-		private Class<T> specificType;
+		private final Class<?> genericType;
+		private final Class<T> specificType;
 
 		public EnumConverter(Class<?> genericType, Class<T> specificType) {
+			Validate.notNull(specificType, "specificType cannot be null");
+			// would love to check if genericType is null, but it breaks other stuff
+
 			this.genericType = genericType;
 			this.specificType = specificType;
 		}
@@ -806,10 +815,6 @@ public abstract class EnumWrappers {
 		public Class<T> getSpecificType() {
 			return specificType;
 		}
-
-		void setGenericType(Class<?> genericType) {
-			this.genericType = genericType;
-		}
 	}
 
 	public interface AliasedEnum {

src/main/java/com/comphenix/protocol/wrappers/MovingObjectPositionBlock.java

@@ -10,7 +10,8 @@ import com.comphenix.protocol.wrappers.EnumWrappers.Direction;
 import org.bukkit.util.Vector;
 
 public class MovingObjectPositionBlock implements Cloneable {
-	private static final Class<?> NMS_CLASS = MinecraftReflection.getNullableNMS("MovingObjectPositionBlock");
+	private static final Class<?> NMS_CLASS = MinecraftReflection.getNullableNMS(
+			"world.phys.MovingObjectPositionBlock", "MovingObjectPositionBlock");
 
 	private BlockPosition position;
 	private Vector posVector;

src/main/java/com/comphenix/protocol/wrappers/PlayerInfoData.java

@@ -17,10 +17,14 @@
 package com.comphenix.protocol.wrappers;
 
 import java.lang.reflect.Constructor;
+import java.util.ArrayList;
+import java.util.List;
 
+import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.wrappers.EnumWrappers.NativeGameMode;
 import com.google.common.base.Objects;
 
@@ -94,14 +98,17 @@ public class PlayerInfoData {
 			public Object getGeneric(PlayerInfoData specific) {
 				if (constructor == null) {
 					try {
-						// public PlayerInfoData(Packet, GameProfile, int, GameMode, ChatComponent)
-						constructor = MinecraftReflection.getPlayerInfoDataClass().getConstructor(
-								MinecraftReflection.getMinecraftClass("PacketPlayOutPlayerInfo"),
-								MinecraftReflection.getGameProfileClass(),
-								int.class,
-								EnumWrappers.getGameModeClass(),
-								MinecraftReflection.getIChatBaseComponentClass()
-						);
+						List<Class<?>> args = new ArrayList<>();
+						if (!MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+							args.add(PacketType.Play.Server.PLAYER_INFO.getPacketClass());
+						}
+
+						args.add(MinecraftReflection.getGameProfileClass());
+						args.add(int.class);
+						args.add(EnumWrappers.getGameModeClass());
+						args.add(MinecraftReflection.getIChatBaseComponentClass());
+
+						constructor = MinecraftReflection.getPlayerInfoDataClass().getConstructor(args.toArray(new Class<?>[0]));
 					} catch (Exception e) {
 						throw new RuntimeException("Cannot find PlayerInfoData constructor.", e);
 					}
@@ -110,16 +117,14 @@ public class PlayerInfoData {
 				// Attempt to construct the underlying PlayerInfoData
 
 				try {
-					// public PlayerInfoData(null, GameProfile, ping, GameMode, ChatComponent)
-					// The packet isn't a field, so it can be null
-					Object result = constructor.newInstance(
-							null,
-							specific.profile.handle,
-							specific.latency,
-							EnumWrappers.getGameModeConverter().getGeneric(specific.gameMode),
-							specific.displayName != null ? specific.displayName.handle : null
-					);
-					return result;
+					Object gameMode = EnumWrappers.getGameModeConverter().getGeneric(specific.gameMode);
+					Object displayName = specific.displayName != null ? specific.displayName.handle : null;
+
+					if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+						return constructor.newInstance(specific.profile.handle, specific.latency, gameMode, displayName);
+					} else {
+						return constructor.newInstance(null, specific.profile.handle, specific.latency, gameMode, displayName);
+					}
 				} catch (Exception e) {
 					throw new RuntimeException("Failed to construct PlayerInfoData.", e);
 				}

src/main/java/com/comphenix/protocol/wrappers/Vector3F.java

@@ -83,10 +83,10 @@ public class Vector3F {
 	}
 
 	private static Constructor<?> constructor = null;
-	private static Class<?> clazz = MinecraftReflection.getMinecraftClass("Vector3f");
+	private static final Class<?> NMS_CLASS = MinecraftReflection.getNullableNMS("core.Vector3f","Vector3f");
 
 	public static Class<?> getMinecraftClass() {
-		return clazz;
+		return NMS_CLASS;
 	}
 
 	public static EquivalentConverter<Vector3F> getConverter() {
@@ -100,7 +100,7 @@ public class Vector3F {
 			public Object getGeneric(Vector3F specific) {
 				if (constructor == null) {
 					try {
-						constructor = clazz.getConstructor(float.class, float.class, float.class);
+						constructor = NMS_CLASS.getConstructor(float.class, float.class, float.class);
 					} catch (ReflectiveOperationException ex) {
 						throw new RuntimeException("Failed to find constructor for Vector3f", ex);
 					}

src/main/java/com/comphenix/protocol/wrappers/WrappedAttribute.java

@@ -3,13 +3,12 @@ package com.comphenix.protocol.wrappers;
 import java.lang.reflect.Constructor;
 import java.util.*;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.reflect.FuzzyReflection;
 import com.comphenix.protocol.reflect.StructureModifier;
-import com.comphenix.protocol.reflect.accessors.Accessors;
-import com.comphenix.protocol.reflect.accessors.MethodAccessor;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
@@ -34,9 +33,6 @@ public class WrappedAttribute extends AbstractWrapper {
 	// The one constructor
 	private static Constructor<?> ATTRIBUTE_CONSTRUCTOR;
 
-	private static Object REGISTRY = null;
-	private static MethodAccessor REGISTRY_GET = null;
-
 	private static final Map<String, String> REMAP;
 
 	static {
@@ -76,7 +72,7 @@ public class WrappedAttribute extends AbstractWrapper {
 		
 		// Initialize modifier
 		if (ATTRIBUTE_MODIFIER == null) {
-			ATTRIBUTE_MODIFIER = new StructureModifier<Object>(MinecraftReflection.getAttributeSnapshotClass());
+			ATTRIBUTE_MODIFIER = new StructureModifier<>(MinecraftReflection.getAttributeSnapshotClass());
 		}
 		this.modifier = ATTRIBUTE_MODIFIER.withTarget(handle);
 	}
@@ -115,7 +111,9 @@ public class WrappedAttribute extends AbstractWrapper {
 		public String key;
 	}
 
-	private static final Class<?> ATTRIBUTE_BASE_CLASS = MinecraftReflection.getNullableNMS("AttributeBase");
+	private static final Class<?> ATTRIBUTE_BASE_CLASS = MinecraftReflection.getNullableNMS(
+			"world.entity.ai.attributes.AttributeBase", "AttributeBase"
+	);
 
 	private static final AutoWrapper<WrappedAttributeBase> ATTRIBUTE_BASE = AutoWrapper.wrap(
 			WrappedAttributeBase.class, ATTRIBUTE_BASE_CLASS
@@ -167,8 +165,14 @@ public class WrappedAttribute extends AbstractWrapper {
 	/**
 	 * Retrieve the parent update attributes packet.
 	 * @return The parent packet.
+	 * @deprecated Removed in 1.17
 	 */
+	@Nullable
 	public PacketContainer getParentPacket() {
+		if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+			return null;
+		}
+
 		return new PacketContainer(
 			PacketType.Play.Server.UPDATE_ATTRIBUTES,
 			modifier.withType(MinecraftReflection.getPacketClass()).read(0)
@@ -223,7 +227,7 @@ public class WrappedAttribute extends AbstractWrapper {
 				}
 			};
 			
-			attributeModifiers = new CachedSet<WrappedAttributeModifier>(converted);
+			attributeModifiers = new CachedSet<>(converted);
 		}
 		return Collections.unmodifiableSet(attributeModifiers);
 	}
@@ -246,9 +250,7 @@ public class WrappedAttribute extends AbstractWrapper {
 			
 			if (getBaseValue() == other.getBaseValue() &&
 				   Objects.equal(getAttributeKey(), other.getAttributeKey())) {
-				return getModifiers().stream()
-						.filter((elem) -> !other.getModifiers().contains(elem))
-						.count() == 0;
+				return other.getModifiers().containsAll(getModifiers());
 			}
 		}
 		return false;
@@ -411,45 +413,33 @@ public class WrappedAttribute extends AbstractWrapper {
 		 * @throws RuntimeException If anything went wrong with the reflection.
 		 */
 		public WrappedAttribute build() {
-			Preconditions.checkNotNull(packet, "packet cannot be NULL.");
 			Preconditions.checkNotNull(attributeKey, "attributeKey cannot be NULL.");
 			
 			// Remember to set the base value
 			if (Double.isNaN(baseValue)) {
 				throw new IllegalStateException("Base value has not been set.");
 			}
-			
-			// Retrieve the correct constructor
+
+			boolean isStatic = MinecraftVersion.CAVES_CLIFFS_1.atOrAbove();
+
 			if (ATTRIBUTE_CONSTRUCTOR == null) {
-				ATTRIBUTE_CONSTRUCTOR = FuzzyReflection.fromClass(MinecraftReflection.getAttributeSnapshotClass(), true)
-						.getConstructor(FuzzyMethodContract.newBuilder().parameterCount(4)
-								.parameterDerivedOf(MinecraftReflection.getPacketClass(), 0)
-								.parameterExactType(double.class, 2).parameterDerivedOf(Collection.class, 3)
-								.build()
-						);
+				FuzzyReflection ref = FuzzyReflection.fromClass(MinecraftReflection.getAttributeSnapshotClass(), true);
+				FuzzyMethodContract.Builder contract = FuzzyMethodContract.newBuilder().parameterCount(isStatic ? 3 : 4);
+				if (!isStatic) {
+					contract.parameterDerivedOf(MinecraftReflection.getPacketClass(), 0);
+				}
+				contract.parameterExactType(double.class).parameterDerivedOf(Collection.class);
+				ATTRIBUTE_CONSTRUCTOR = ref.getConstructor(contract.build());
+
 				// Just in case
 				ATTRIBUTE_CONSTRUCTOR.setAccessible(true);
 			}
 
 			Object attributeKey;
 			if (KEY_WRAPPED) {
-				if (REGISTRY == null) {
-					Class<?> iRegistry = MinecraftReflection.getMinecraftClass("IRegistry");
-					try {
-						REGISTRY = iRegistry.getDeclaredField("ATTRIBUTE").get(null);
-					} catch (ReflectiveOperationException ex) {
-						throw new RuntimeException("Failed to obtain ATTRIBUTE registry", ex);
-					}
-				}
-
-				if (REGISTRY_GET == null) {
-					Class<?> keyClass = MinecraftReflection.getMinecraftKeyClass();
-					REGISTRY_GET = Accessors.getMethodAccessor(REGISTRY.getClass(), "get", keyClass);
-				}
-
+				WrappedRegistry registry = WrappedRegistry.getAttributeRegistry();
 				String strKey = REMAP.getOrDefault(this.attributeKey, this.attributeKey);
-				Object key = MinecraftKey.getConverter().getGeneric(new MinecraftKey(strKey));
-				attributeKey = REGISTRY_GET.invoke(REGISTRY, key);
+				attributeKey = registry.get(strKey);
 
 				if (attributeKey == null) {
 					throw new IllegalArgumentException("Invalid attribute name: " + this.attributeKey);
@@ -459,15 +449,14 @@ public class WrappedAttribute extends AbstractWrapper {
 			}
 
 			try {
-				Object handle = ATTRIBUTE_CONSTRUCTOR.newInstance(
-					packet.getHandle(),
-					attributeKey,
-					baseValue,
-					getUnwrappedModifiers());
+				Object handle;
+				if (isStatic) {
+					handle = ATTRIBUTE_CONSTRUCTOR.newInstance(attributeKey, baseValue, getUnwrappedModifiers());
+				} else {
+					handle = ATTRIBUTE_CONSTRUCTOR.newInstance(packet.getHandle(), attributeKey, baseValue, getUnwrappedModifiers());
+				}
 
-				// Create it
 				return new WrappedAttribute(handle);
-				
 			} catch (Exception e) {
 				throw new RuntimeException("Cannot construct AttributeSnapshot.", e);
 			}

src/main/java/com/comphenix/protocol/wrappers/WrappedAttributeModifier.java

@@ -66,7 +66,9 @@ public class WrappedAttributeModifier extends AbstractWrapper {
 	}
 
 	static {
-		OPERATION_CLASS = OPERATION_ENUM ? MinecraftReflection.getMinecraftClass("AttributeModifier$Operation") : null;
+		OPERATION_CLASS = OPERATION_ENUM ? MinecraftReflection.getMinecraftClass(
+				"world.entity.ai.attributes.AttributeModifier$Operation", "AttributeModifier$Operation"
+		) : null;
 		OPERATION_CONVERTER = OPERATION_ENUM ? new IndexedEnumConverter<>(Operation.class, OPERATION_CLASS) : null;
 	}
 

src/main/java/com/comphenix/protocol/wrappers/WrappedChatComponent.java

@@ -42,7 +42,7 @@ public class WrappedChatComponent extends AbstractWrapper implements ClonableWra
 		}
 
 		try {
-			DESERIALIZE = Accessors.getMethodAccessor(FuzzyReflection.fromClass(MinecraftReflection.getMinecraftClass("ChatDeserializer"), true)
+			DESERIALIZE = Accessors.getMethodAccessor(FuzzyReflection.fromClass(MinecraftReflection.getChatDeserializer(), true)
 				.getMethodByParameters("deserialize", Object.class, new Class<?>[] { GSON_CLASS, String.class, Class.class, boolean.class }));
 		} catch (IllegalArgumentException ex) {
 			// We'll handle it in the ComponentParser
@@ -50,7 +50,7 @@ public class WrappedChatComponent extends AbstractWrapper implements ClonableWra
 		}
 
 		// Get a component from a standard Minecraft message
-		CONSTRUCT_COMPONENT = Accessors.getMethodAccessor(MinecraftReflection.getCraftChatMessage(), "fromString", String.class);
+		CONSTRUCT_COMPONENT = Accessors.getMethodAccessor(MinecraftReflection.getCraftChatMessage(), "fromString", String.class, boolean.class);
 
 		// And the component text constructor
 		CONSTRUCT_TEXT_COMPONENT = Accessors.getConstructorAccessor(MinecraftReflection.getChatComponentTextClass(), String.class);
@@ -95,6 +95,9 @@ public class WrappedChatComponent extends AbstractWrapper implements ClonableWra
 	
 	/**
 	 * Construct a wrapper around a new text chat component with the given text.
+	 * <p>
+	 * Note: {@link #fromLegacyText(String)} is preferred for text that contains
+	 * legacy formatting codes since it will translate them to the JSON equivalent.
 	 * @param text - the text of the text chat component.
 	 * @return The wrapper around the new chat component.
 	 */
@@ -111,7 +114,7 @@ public class WrappedChatComponent extends AbstractWrapper implements ClonableWra
 	 * @return The equivalent chat components.
 	 */
 	public static WrappedChatComponent[] fromChatMessage(String message) {
-		Object[] components = (Object[]) CONSTRUCT_COMPONENT.invoke(null, message);
+		Object[] components = (Object[]) CONSTRUCT_COMPONENT.invoke(null, message, false);
 		WrappedChatComponent[] result = new WrappedChatComponent[components.length];
 		
 		for (int i = 0; i < components.length; i++) {
@@ -120,6 +123,18 @@ public class WrappedChatComponent extends AbstractWrapper implements ClonableWra
 		return result;
 	}
 
+	/**
+	 * Construct a single chat component from a standard Minecraft message
+	 * (with legacy formatting codes), preserving multiple lines.
+	 * @param message - the message.
+	 * @return The equivalent chat component.
+	 */
+	public static WrappedChatComponent fromLegacyText(String message) {
+		// With keepNewlines = true (second parameter), only one component is returned
+		Object[] components = (Object[]) CONSTRUCT_COMPONENT.invoke(null, message, true);
+		return fromHandle(components[0]);
+	}
+
 	/**
 	 * Retrieve a copy of this component as a JSON string.
 	 * <p>

src/main/java/com/comphenix/protocol/wrappers/WrappedDataWatcher.java

@@ -129,8 +129,10 @@ public class WrappedDataWatcher extends AbstractWrapper implements Iterable<Wrap
 		// We can create a fake egg without it affecting anything
 		// Mojang added difficulty to lightning strikes, so this'll have to do
 		if (eggConstructor == null) {
-			eggConstructor = Accessors.getConstructorAccessor(MinecraftReflection.getMinecraftClass("EntityEgg"),
-					MinecraftReflection.getNmsWorldClass(), double.class, double.class, double.class);
+			eggConstructor = Accessors.getConstructorAccessor(
+					MinecraftReflection.getMinecraftClass("world.entity.projectile.EntityEgg", "EntityEgg"),
+					MinecraftReflection.getNmsWorldClass(), double.class, double.class, double.class
+			);
 		}
 
 		Object world = BukkitUnwrapper.getInstance().unwrapItem(Bukkit.getWorlds().get(0));

src/main/java/com/comphenix/protocol/wrappers/WrappedEnumEntityUseAction.java

@@ -0,0 +1,200 @@
+package com.comphenix.protocol.wrappers;
+
+import java.lang.reflect.Modifier;
+import java.util.Arrays;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.reflect.EquivalentConverter;
+import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
+import com.comphenix.protocol.reflect.accessors.FieldAccessor;
+import com.comphenix.protocol.reflect.accessors.MethodAccessor;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.wrappers.EnumWrappers.EntityUseAction;
+import com.comphenix.protocol.wrappers.EnumWrappers.Hand;
+
+import org.bukkit.util.Vector;
+
+/**
+ * Represents an entity used action used in the UseEntity packet sent by the client.
+ * @author derklaro
+ */
+public class WrappedEnumEntityUseAction extends AbstractWrapper implements ClonableWrapper {
+
+	public static final EquivalentConverter<WrappedEnumEntityUseAction> CONVERTER = Converters.handle(AbstractWrapper::getHandle,
+			WrappedEnumEntityUseAction::fromHandle, WrappedEnumEntityUseAction.class);
+
+	private static final Class<?> PACKET_CLASS = PacketType.Play.Client.USE_ENTITY.getPacketClass();
+	private static final Class<?>[] DECLARED_CLASSES = PACKET_CLASS.getDeclaredClasses();
+
+	private static final Class<?> HANDLE_TYPE = MinecraftReflection.getEnumEntityUseActionClass();
+	private static final MethodAccessor ACTION_USE = MinecraftReflection.getEntityUseActionEnumMethodAccessor();
+
+	private static final ConstructorAccessor INTERACT = useAction(EnumWrappers.getHandClass());
+	private static final ConstructorAccessor INTERACT_AT = useAction(EnumWrappers.getHandClass(),
+			MinecraftReflection.getVec3DClass());
+
+	private static final Object ATTACK = Accessors.getFieldAccessor(FuzzyReflection.fromClass(PACKET_CLASS, true)
+			.getField(FuzzyFieldContract.newBuilder()
+					.requireModifier(Modifier.STATIC)
+					.typeExact(MinecraftReflection.getEnumEntityUseActionClass())
+					.build())
+	).get(null);
+	private static final WrappedEnumEntityUseAction ATTACK_WRAPPER = new WrappedEnumEntityUseAction(ATTACK);
+
+	private final EntityUseAction action;
+	// these fields are only available for interact & interact_at
+	private FieldAccessor handAccessor;
+	private FieldAccessor positionAccessor;
+
+	/**
+	 * Construct a new wrapper for the entity use action class in the UseEntity packet.
+	 * @param handle - the NMS handle.
+	 */
+	private WrappedEnumEntityUseAction(Object handle) {
+		super(HANDLE_TYPE);
+		setHandle(handle);
+
+		action = EnumWrappers.getEntityUseActionConverter().getSpecific(ACTION_USE.invoke(handle));
+	}
+
+	/**
+	 * Finds a constructor of a declared class in the UseEntity class. Used to find the action class implementations.
+	 * @param parameterTypes - the types the constructor of the class must have.
+	 * @return a constructor for a matching class.
+	 * @throws IllegalArgumentException if no constructor was found.
+	 */
+	private static ConstructorAccessor useAction(Class<?>... parameterTypes) {
+		for (Class<?> subClass : DECLARED_CLASSES) {
+			ConstructorAccessor accessor = Accessors.getConstructorAccessorOrNull(subClass, parameterTypes);
+			if (accessor != null) {
+				return accessor;
+			}
+		}
+		throw new IllegalArgumentException(
+				"No constructor with " + Arrays.toString(parameterTypes) + " in " + PACKET_CLASS);
+	}
+
+	/**
+	 * Construct a new wrapper for the entity use action class in the UseEntity packet.
+	 * @param handle - the NMS handle.
+	 * @return the created wrapper.
+	 */
+	public static WrappedEnumEntityUseAction fromHandle(Object handle) {
+		return new WrappedEnumEntityUseAction(handle);
+	}
+
+	/**
+	 * Get the jvm static action for attacking an entity.
+	 * @return the action for an entity attack.
+	 */
+	public static WrappedEnumEntityUseAction attack() {
+		return ATTACK_WRAPPER;
+	}
+
+	/**
+	 * Get an action for interacting with an entity.
+	 * @param hand - the hand used for the interact.
+	 * @return the action for an interact.
+	 */
+	public static WrappedEnumEntityUseAction interact(Hand hand) {
+		Object handle = INTERACT.invoke(EnumWrappers.getHandConverter().getGeneric(hand));
+		return new WrappedEnumEntityUseAction(handle);
+	}
+
+	/**
+	 * Get an action for interacting with an entity at a specific location.
+	 * @param hand - the hand used for the interact.
+	 * @param vector - the position of the interact.
+	 * @return the action for an interact_at.
+	 */
+	public static WrappedEnumEntityUseAction interactAt(Hand hand, Vector vector) {
+		Object handle = INTERACT_AT.invoke(EnumWrappers.getHandConverter().getGeneric(hand),
+				BukkitConverters.getVectorConverter().getGeneric(vector));
+		return new WrappedEnumEntityUseAction(handle);
+	}
+
+	/**
+	 * Get the action used for the interact.
+	 * @return the interact action.
+	 */
+	public EntityUseAction getAction() {
+		return action;
+	}
+
+	/**
+	 * Get the hand used for the interact. Only available if this represents interact or interact_at.
+	 * @return the hand used for the interact.
+	 * @throws IllegalArgumentException if called for attack.
+	 */
+	public Hand getHand() {
+		return EnumWrappers.getHandConverter().getSpecific(getHandAccessor().get(handle));
+	}
+
+	/**
+	 * Sets the hand used for the interact.
+	 * @param hand the used hand.
+	 * @throws IllegalArgumentException if called for attack.
+	 */
+	public void setHand(Hand hand) {
+		getHandAccessor().set(handle, EnumWrappers.getHandConverter().getGeneric(hand));
+	}
+
+	/**
+	 * Get the position of the interact. Only available if this represents interact_at.
+	 * @return the position of the interact.
+	 * @throws IllegalArgumentException if called for attack or interact.
+	 */
+	public Vector getPosition() {
+		return BukkitConverters.getVectorConverter().getSpecific(getPositionAccessor().get(handle));
+	}
+
+	/**
+	 * Sets the position of the interact.
+	 * @param position the position.
+	 * @throws IllegalArgumentException if called for attack or interact.
+	 */
+	public void setPosition(Vector position) {
+		getPositionAccessor().set(handle, BukkitConverters.getVectorConverter().getGeneric(position));
+	}
+
+	@Override
+	public WrappedEnumEntityUseAction deepClone() {
+		switch (action) {
+			case ATTACK:
+				return WrappedEnumEntityUseAction.attack();
+			case INTERACT:
+				return WrappedEnumEntityUseAction.interact(getHand());
+			case INTERACT_AT:
+				return WrappedEnumEntityUseAction.interactAt(getHand(), getPosition());
+			default:
+				throw new IllegalArgumentException("Invalid EntityUseAction: " + action);
+		}
+	}
+
+	/**
+	 * Get a field accessor for the hand in the interact and interact_at type.
+	 * @return a field accessor for the hand field.
+	 * @throws IllegalArgumentException if called for attack.
+	 */
+	private FieldAccessor getHandAccessor() {
+		if (handAccessor == null) {
+			handAccessor = MinecraftReflection.getHandEntityUseActionEnumFieldAccessor(handle);
+		}
+		return handAccessor;
+	}
+
+	/**
+	 * Get a field accessor for the position in the interact_at type.
+	 * @return a field accessor for the position field.
+	 * @throws IllegalArgumentException if called for attack or interact.
+	 */
+	public FieldAccessor getPositionAccessor() {
+		if (positionAccessor == null) {
+			positionAccessor = MinecraftReflection.getVec3EntityUseActionEnumFieldAccessor(handle);
+		}
+		return positionAccessor;
+	}
+}

src/main/java/com/comphenix/protocol/wrappers/WrappedParticle.java

@@ -9,6 +9,8 @@ import com.comphenix.protocol.reflect.accessors.MethodAccessor;
 import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
 import com.comphenix.protocol.utility.MinecraftReflection;
 
+import com.comphenix.protocol.utility.MinecraftVersion;
+import com.mojang.math.Vector3fa;
 import org.bukkit.Color;
 import org.bukkit.Particle;
 import org.bukkit.inventory.ItemStack;
@@ -31,14 +33,14 @@ public class WrappedParticle<T> {
 				.newBuilder()
 				.requireModifier(Modifier.STATIC)
 				.returnTypeExact(Particle.class)
-				.parameterExactType(MinecraftReflection.getMinecraftClass("ParticleParam"))
+				.parameterExactType(MinecraftReflection.getParticleParam())
 				.build();
 		toBukkit = Accessors.getMethodAccessor(fuzzy.getMethod(contract));
 
 		contract = FuzzyMethodContract
 				.newBuilder()
 				.requireModifier(Modifier.STATIC)
-				.returnTypeExact(MinecraftReflection.getMinecraftClass("ParticleParam"))
+				.returnTypeExact(MinecraftReflection.getParticleParam())
 				.parameterCount(2)
 				.build();
 		toNMS = Accessors.getMethodAccessor(fuzzy.getMethod(contract));
@@ -130,12 +132,26 @@ public class WrappedParticle<T> {
 	}
 
 	private static Object getRedstone(Object handle) {
-		StructureModifier<Float> modifier = new StructureModifier<>(handle.getClass()).withTarget(handle).withType(float.class);
-		return new Particle.DustOptions(Color.fromRGB(
-				(int) (modifier.read(0) * 255),
-				(int) (modifier.read(1) * 255),
-				(int) (modifier.read(2) * 255)),
-				modifier.read(3));
+		int r, g, b;
+		float alpha;
+
+		if (MinecraftVersion.CAVES_CLIFFS_1.atOrAbove()) {
+			StructureModifier<Object> modifier = new StructureModifier<>(handle.getClass()).withTarget(handle);
+			Vector3fa rgb = (Vector3fa) modifier.withType(Vector3fa.class).read(0);
+
+			r = (int) (rgb.a() * 255);
+			g = (int) (rgb.b() * 255);
+			b = (int) (rgb.c() * 255);
+			alpha = (float) modifier.withType(float.class).read(0);
+		} else {
+			StructureModifier<Float> modifier = new StructureModifier<>(handle.getClass()).withTarget(handle).withType(float.class);
+			r = (int) (modifier.read(0) * 255);
+			g = (int) (modifier.read(1) * 255);
+			b = (int) (modifier.read(2) * 255);
+			alpha = modifier.read(3);
+		}
+
+		return new Particle.DustOptions(Color.fromRGB(r, g, b), alpha);
 	}
 
 	public static <T> WrappedParticle<T> create(Particle particle, T data) {

src/main/java/com/comphenix/protocol/wrappers/WrappedRegistry.java

@@ -0,0 +1,86 @@
+package com.comphenix.protocol.wrappers;
+
+import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.accessors.Accessors;
+import com.comphenix.protocol.reflect.accessors.MethodAccessor;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyMethodContract;
+import com.comphenix.protocol.utility.MinecraftReflection;
+import com.comphenix.protocol.utility.MinecraftVersion;
+import com.google.common.collect.ImmutableMap;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.Map;
+
+public class WrappedRegistry {
+    // map of NMS class to registry instance
+    private static final Map<Class<?>, WrappedRegistry> REGISTRY;
+
+    private static final MethodAccessor GET;
+    private static final MethodAccessor GET_KEY;
+
+    static {
+        Map<Class<?>, WrappedRegistry> regMap = new HashMap<>();
+
+        Class<?> regClass = MinecraftReflection.getIRegistry();
+        if (regClass != null) {
+            for (Field field : regClass.getFields()) {
+                try {
+                    // make sure it's actually a registry
+                    if (field.getType().isAssignableFrom(regClass)) {
+                        Type genType = field.getGenericType();
+                        if (genType instanceof ParameterizedType) {
+                            ParameterizedType par = (ParameterizedType) genType;
+                            Type paramType = par.getActualTypeArguments()[0];
+                            if (paramType instanceof Class) {
+                                regMap.put((Class<?>) paramType, new WrappedRegistry(field.get(null)));
+                            }
+                        }
+                    }
+                } catch (ReflectiveOperationException ignored) {
+                }
+            }
+        }
+
+        REGISTRY = ImmutableMap.copyOf(regMap);
+
+        GET = Accessors.getMethodAccessor(regClass, "get", MinecraftReflection.getMinecraftKeyClass());
+
+        FuzzyReflection fuzzy = FuzzyReflection.fromClass(regClass, false);
+        GET_KEY = Accessors.getMethodAccessor(fuzzy.getMethod(FuzzyMethodContract
+                .newBuilder()
+                .parameterCount(1)
+                .returnTypeExact(MinecraftReflection.getMinecraftKeyClass())
+                .build()));
+    }
+
+    private final Object handle;
+
+    private WrappedRegistry(Object handle) {
+        this.handle = handle;
+    }
+
+    public Object get(MinecraftKey key) {
+        return GET.invoke(handle, MinecraftKey.getConverter().getGeneric(key));
+    }
+
+    public Object get(String key) {
+        return get(new MinecraftKey(key));
+    }
+
+    public MinecraftKey getKey(Object generic) {
+        return MinecraftKey.getConverter().getSpecific(GET_KEY.invoke(handle, generic));
+    }
+
+    // TODO add more methods
+
+    public static WrappedRegistry getAttributeRegistry() {
+        return REGISTRY.get(MinecraftReflection.getAttributeBase());
+    }
+
+    public static WrappedRegistry getDimensionRegistry() {
+        return REGISTRY.get(MinecraftReflection.getDimensionManager());
+    }
+}

src/main/java/com/comphenix/protocol/wrappers/WrappedServerPing.java

@@ -161,7 +161,7 @@ public class WrappedServerPing extends AbstractWrapper implements ClonableWrappe
 	 * @param message - the message.
 	 */
 	public void setMotD(String message) {
-		setMotD(WrappedChatComponent.fromText(message));
+		setMotD(WrappedChatComponent.fromLegacyText(message));
 	}
 
 	/**

src/main/java/com/comphenix/protocol/wrappers/WrappedVillagerData.java

@@ -7,9 +7,12 @@ import com.comphenix.protocol.reflect.accessors.ConstructorAccessor;
 import com.comphenix.protocol.utility.MinecraftReflection;
 
 public class WrappedVillagerData extends AbstractWrapper implements ClonableWrapper {
-    private static final Class<?> NMS_CLASS = MinecraftReflection.getNullableNMS("VillagerData");
-    private static final Class<?> TYPE_CLASS = MinecraftReflection.getNullableNMS("VillagerType");
-    private static final Class<?> PROF_CLASS = MinecraftReflection.getNullableNMS("VillagerProfession");
+    private static final Class<?> NMS_CLASS = MinecraftReflection.getNullableNMS(
+            "world.entity.npc.VillagerData","VillagerData");
+    private static final Class<?> TYPE_CLASS = MinecraftReflection.getNullableNMS(
+            "world.entity.npc.VillagerType", "VillagerType");
+    private static final Class<?> PROF_CLASS = MinecraftReflection.getNullableNMS(
+            "world.entity.npc.VillagerProfession", "VillagerProfession");
 
     private static EquivalentConverter<Type> TYPE_CONVERTER;
     private static EquivalentConverter<Profession> PROF_CONVERTER;

src/main/java/com/comphenix/protocol/wrappers/nbt/NbtFactory.java

@@ -592,7 +592,7 @@ public class NbtFactory {
 		Constructor<?> constructor = CONSTRUCTORS.get(type);
 		if (constructor == null) {
 			if (getTagType == null) {
-				Class<?> tagTypes = MinecraftReflection.getMinecraftClass("NBTTagTypes");
+				Class<?> tagTypes = MinecraftReflection.getNbtTagTypes();
 				FuzzyReflection fuzzy = FuzzyReflection.fromClass(tagTypes, false);
 				getTagType = fuzzy.getMethod(
 						FuzzyMethodContract.newBuilder().parameterCount(1).parameterExactType(int.class).build());

src/main/java/com/comphenix/protocol/wrappers/nbt/TileEntityAccessor.java

@@ -35,7 +35,8 @@ import org.bukkit.block.BlockState;
  * @author Kristian
  */
 class TileEntityAccessor<T extends BlockState> {
-	private static final boolean BLOCK_DATA_INCL = MinecraftVersion.NETHER_UPDATE.atOrAbove();
+	private static final boolean BLOCK_DATA_INCL = MinecraftVersion.NETHER_UPDATE.atOrAbove()
+			&& !MinecraftVersion.CAVES_CLIFFS_1.atOrAbove();
 
 	/**
 	 * Token indicating that the given block state doesn't contain any tile entities.

src/test/java/com/comphenix/protocol/BukkitInitialization.java

@@ -5,18 +5,21 @@ import java.util.List;
 
 import com.comphenix.protocol.reflect.FieldUtils;
 import com.comphenix.protocol.utility.Constants;
+import com.mojang.bridge.game.GameVersion;
 
-import net.minecraft.server.v1_16_R3.DispenserRegistry;
-import net.minecraft.server.v1_16_R3.WorldServer;
+import net.minecraft.SharedConstants;
+import net.minecraft.core.IRegistry;
+import net.minecraft.server.DispenserRegistry;
+import net.minecraft.server.level.WorldServer;
 
 import org.apache.logging.log4j.LogManager;
 import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.bukkit.World;
-import org.bukkit.craftbukkit.v1_16_R3.CraftServer;
-import org.bukkit.craftbukkit.v1_16_R3.CraftWorld;
-import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftItemFactory;
-import org.bukkit.craftbukkit.v1_16_R3.util.Versioning;
+import org.bukkit.craftbukkit.v1_17_R1.CraftServer;
+import org.bukkit.craftbukkit.v1_17_R1.CraftWorld;
+import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftItemFactory;
+import org.bukkit.craftbukkit.v1_17_R1.util.Versioning;
 import org.spigotmc.SpigotWorldConfig;
 
 import static org.mockito.Mockito.mock;
@@ -53,8 +56,6 @@ public class BukkitInitialization {
 			// Denote that we're done
 			initialized = true;
 
-			initializePackage();
-
 			try {
 				LogManager.getLogger();
 			} catch (Throwable ex) {
@@ -62,8 +63,17 @@ public class BukkitInitialization {
 				ex.printStackTrace();
 			}
 
+			initializePackage();
+
+			SharedConstants.a();
 			DispenserRegistry.init();
 
+			try {
+				IRegistry.class.getName();
+			} catch (Throwable ex) {
+				ex.printStackTrace();
+			}
+
 			// Mock the server object
 			Server mockedServer = mock(Server.class);
 

src/test/java/com/comphenix/protocol/PacketTypeTest.java

@@ -22,14 +22,15 @@ import java.util.Map.Entry;
 
 import com.comphenix.protocol.PacketType.Protocol;
 import com.comphenix.protocol.PacketType.Sender;
+import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.injector.packet.PacketRegistry;
 import com.comphenix.protocol.utility.Constants;
 import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
 
-import net.minecraft.server.v1_16_R3.EnumProtocol;
-import net.minecraft.server.v1_16_R3.EnumProtocolDirection;
-import net.minecraft.server.v1_16_R3.PacketLoginInStart;
+import net.minecraft.network.EnumProtocol;
+import net.minecraft.network.protocol.EnumProtocolDirection;
+import net.minecraft.network.protocol.login.PacketLoginInStart;
 
 import org.apache.commons.lang.WordUtils;
 import org.junit.AfterClass;
@@ -45,9 +46,11 @@ public class PacketTypeTest {
 
 	@BeforeClass
 	public static void beforeClass() {
+		BukkitInitialization.initializeItemMeta();
+
 		// I'm well aware this is jank, but it does in fact work correctly and give the desired result
 		PacketType.onDynamicCreate = className -> {
-			throw new RuntimeException("Dynamically generated packet " + className);
+			 throw new RuntimeException("Dynamically generated packet " + className);
 		};
 	}
 
@@ -67,7 +70,7 @@ public class PacketTypeTest {
 		for (EnumProtocol protocol : protocols) {
 			System.out.println(WordUtils.capitalize(protocol.name().toLowerCase()));
 
-			Field field = EnumProtocol.class.getDeclaredField("h");
+			Field field = EnumProtocol.class.getDeclaredField("j");
 			field.setAccessible(true);
 
 			Map<EnumProtocolDirection, Object> map = (Map<EnumProtocolDirection, Object>) field.get(protocol);
@@ -144,17 +147,30 @@ public class PacketTypeTest {
 		String fullName = clazz.getName();
 		fullName = fullName.substring(fullName.lastIndexOf(".") + 1);
 
-		List<String> classNames = new ArrayList<>(2);
-		for (String name : fullName.split("\\$")) {
-			List<String> split = splitOnCaps(name);
-			StringBuilder nameBuilder = new StringBuilder();
-			for (int i = 3; i < split.size(); i++) {
-				nameBuilder.append(split.get(i));
+		String className;
+		List<String> classNames = new ArrayList<>();
+
+		if (fullName.endsWith("Packet")) {
+			for (String name : fullName.split("\\$")) {
+				List<String> split = splitOnCaps(name);
+				StringBuilder nameBuilder = new StringBuilder();
+				for (int i = 1; i < split.size() - 1; i++) {
+					nameBuilder.append(split.get(i));
+				}
+				classNames.add(nameBuilder.toString());
+			}
+		} else {
+			for (String name : fullName.split("\\$")) {
+				List<String> split = splitOnCaps(name);
+				StringBuilder nameBuilder = new StringBuilder();
+				for (int i = 3; i < split.size(); i++) {
+					nameBuilder.append(split.get(i));
+				}
+				classNames.add(nameBuilder.toString());
 			}
-			classNames.add(nameBuilder.toString());
 		}
 
-		String className = classNames.get(classNames.size() - 1);
+		className = classNames.get(classNames.size() - 1);
 
 		// Format it like SET_PROTOCOL
 		StringBuilder fieldName = new StringBuilder();
@@ -208,6 +224,7 @@ public class PacketTypeTest {
 		try {
 			PacketType type = PacketType.fromClass(packetClass);
 			for (String alias : type.names) {
+				alias = alias.substring(alias.lastIndexOf('.') + 1);
 				if (!names.contains(alias)) {
 					names.add(alias);
 				}
@@ -262,7 +279,7 @@ public class PacketTypeTest {
 
 		EnumProtocol[] protocols = EnumProtocol.values();
 		for (EnumProtocol protocol : protocols) {
-			Field field = EnumProtocol.class.getDeclaredField("h");
+			Field field = EnumProtocol.class.getDeclaredField("j");
 			field.setAccessible(true);
 
 			Map<EnumProtocolDirection, Object> map = (Map<EnumProtocolDirection, Object>) field.get(protocol);
@@ -293,4 +310,20 @@ public class PacketTypeTest {
 
 		assertTrue("Packet type(s) were incorrect!", !fail);
 	}
+
+	@Test
+	public void testPacketCreation() {
+		boolean fail = false;
+		for (PacketType type : PacketType.values()) {
+			if (type.isSupported()) {
+				try {
+					new PacketContainer(type);
+				} catch (Exception ex) {
+					ex.printStackTrace();
+					fail = true;
+				}
+			}
+		}
+		assertFalse("Packet type(s) failed to instantiate", fail);
+	}
 }

src/test/java/com/comphenix/protocol/events/PacketContainerTest.java

@@ -16,6 +16,8 @@
  */
 package com.comphenix.protocol.events;
 
+import com.comphenix.protocol.wrappers.EnumWrappers.EntityUseAction;
+import com.comphenix.protocol.wrappers.EnumWrappers.Hand;
 import java.lang.reflect.Array;
 import java.lang.reflect.Field;
 import java.util.*;
@@ -38,10 +40,20 @@ import com.comphenix.protocol.wrappers.nbt.NbtFactory;
 import com.google.common.collect.Lists;
 
 import net.md_5.bungee.api.chat.*;
-import net.minecraft.server.v1_16_R3.*;
-import net.minecraft.server.v1_16_R3.MinecraftKey;
-import net.minecraft.server.v1_16_R3.PacketPlayOutUpdateAttributes.AttributeSnapshot;
 
+import net.minecraft.core.IRegistry;
+import net.minecraft.network.protocol.game.PacketPlayOutUpdateAttributes;
+import net.minecraft.network.protocol.game.PacketPlayOutUpdateAttributes.AttributeSnapshot;
+import net.minecraft.world.effect.MobEffect;
+import net.minecraft.world.effect.MobEffectList;
+import net.minecraft.world.entity.ai.attributes.AttributeBase;
+import net.minecraft.world.entity.ai.attributes.AttributeModifier;
+import net.minecraft.resources.MinecraftKey;
+import net.minecraft.world.entity.npc.VillagerData;
+import net.minecraft.world.entity.npc.VillagerProfession;
+import net.minecraft.world.entity.npc.VillagerType;
+
+import net.minecraft.world.level.dimension.DimensionManager;
 import org.apache.commons.lang.SerializationUtils;
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.bukkit.ChatColor;
@@ -95,7 +107,7 @@ public class PacketContainerTest {
 
 	private <T> void testObjectArray(StructureModifier<T[]> modifier, int index, T[] initialValue, T[] testValue) {
 		// Check initial value
-		assertNull(modifier.read(index));
+		assertEquals(modifier.read(index).length, initialValue.length);
 		modifier.writeDefaults();
 
 		// Test initial
@@ -133,7 +145,7 @@ public class PacketContainerTest {
 
 	@Test
 	public void testGetShorts() {
-		PacketContainer itemData = new PacketContainer(PacketType.Play.Server.TRANSACTION);
+		PacketContainer itemData = new PacketContainer(PacketType.Play.Server.REL_ENTITY_MOVE);
 		testPrimitive(itemData.getShorts(), 0, (short)0, (short)1);
 	}
 
@@ -164,25 +176,25 @@ public class PacketContainerTest {
 	@Test
 	public void testGetStrings() {
 		PacketContainer explosion = new PacketContainer(PacketType.Play.Client.CHAT);
-		testPrimitive(explosion.getStrings(), 0, null, "hello");
+		testPrimitive(explosion.getStrings(), 0, "", "hello");
 	}
 
 	@Test
 	public void testGetStringArrays() {
 		PacketContainer packet = new PacketContainer(PacketType.Play.Client.UPDATE_SIGN);
-		testObjectArray(packet.getStringArrays(), 0, new String[0], new String[] { "hello", "world" });
+		testObjectArray(packet.getStringArrays(), 0,
+				new String[] { "", "", "", "" },
+				new String[] { "hello", "world" }
+		);
 	}
 
 	@Test
 	public void testGetIntegerArrays() {
 		// Contains a byte array we will test
-		PacketContainer packet = new PacketContainer(PacketType.Play.Server.ENTITY_DESTROY);
+		PacketContainer packet = new PacketContainer(PacketType.Play.Server.MAP_CHUNK);
 		StructureModifier<int[]> integers = packet.getIntegerArrays();
 		int[] testArray = new int[] { 1, 2, 3 };
 
-		// Pre and post conditions
-		assertArrayEquals(null, integers.read(0));
-		packet.getModifier().writeDefaults();
 		assertArrayEquals(new int[0], integers.read(0));
 
 		integers.write(0, testArray);
@@ -221,7 +233,7 @@ public class PacketContainerTest {
 		items.add(itemWithData());
 		items.add(new ItemStack(Material.DIAMOND_AXE));
 
-		assertNull(itemAccess.read(0));
+		assertEquals(itemAccess.read(0).size(), 0);
 
 		// Insert and check that it was succesful
 		itemAccess.write(0, items);
@@ -307,7 +319,7 @@ public class PacketContainerTest {
 		PacketContainer explosionPacket = new PacketContainer(PacketType.Play.Server.EXPLOSION);
 		StructureModifier<List<BlockPosition>> positionAccessor = explosionPacket.getBlockPositionCollectionModifier();
 
-		assertNull(positionAccessor.read(0));
+		assertEquals(positionAccessor.read(0).size(), 0);
 
 		List<BlockPosition> positions = Lists.newArrayList();
 		positions.add(new BlockPosition(1, 2, 3));
@@ -373,6 +385,19 @@ public class PacketContainerTest {
 		assertEquals("Test", copy.getStrings().read(0));
 	}
 
+	@Test
+	public void testIntList() {
+		PacketContainer destroy = new PacketContainer(PacketType.Play.Server.ENTITY_DESTROY);
+		destroy.getIntLists().write(0, new ArrayList<Integer>() {{
+			add(420);
+			add(69);
+		}});
+		List<Integer> back = destroy.getIntLists().read(0);
+		assertEquals(back.size(), 2);
+		assertEquals((int) back.get(0), 420);
+		assertEquals((int) back.get(1), 69);
+	}
+
 	@Test
 	public void testAttributeList() {
 		PacketContainer attribute = new PacketContainer(PacketType.Play.Server.UPDATE_ATTRIBUTES);
@@ -380,18 +405,19 @@ public class PacketContainerTest {
 
 		// Initialize some test data
 		List<AttributeModifier> modifiers = Lists.newArrayList(
-			new AttributeModifier(UUID.randomUUID(), "Unknown synced attribute modifier", 10, AttributeModifier.Operation.ADDITION));
+			new AttributeModifier(UUID.randomUUID(), "Unknown synced attribute modifier", 10, AttributeModifier.Operation.a));
 
 		// Obtain an AttributeSnapshot instance. This is complicated by the fact that AttributeSnapshots
 		// are inner classes (which is ultimately pointless because AttributeSnapshots don't access any
 		// members of the packet itself)
 		PacketPlayOutUpdateAttributes packet = (PacketPlayOutUpdateAttributes) attribute.getHandle();
-		AttributeBase base = IRegistry.ATTRIBUTE.get(MinecraftKey.a("generic.max_health"));
-		AttributeSnapshot snapshot = packet.new AttributeSnapshot(base, 20.0D, modifiers);
+		AttributeBase base = IRegistry.al.get(MinecraftKey.a("generic.max_health"));
+		AttributeSnapshot snapshot = new AttributeSnapshot(base, 20.0D, modifiers);
 		attribute.getSpecificModifier(List.class).write(0, Lists.newArrayList(snapshot));
 
 		PacketContainer cloned = attribute.deepClone();
-		AttributeSnapshot clonedSnapshot = (AttributeSnapshot) cloned.getSpecificModifier(List.class).read(0).get(0);
+		AttributeSnapshot
+				clonedSnapshot = (AttributeSnapshot) cloned.getSpecificModifier(List.class).read(0).get(0);
 
 		// Compare the fields, because apparently the packet is a field in AttributeSnapshot
 		for (Field field : AttributeSnapshot.class.getDeclaredFields()) {
@@ -402,7 +428,7 @@ public class PacketContainerTest {
 				}
 
 				field.setAccessible(true);
-				assertEquals(field.get(snapshot), field.get(clonedSnapshot));
+				testEquality(field.get(snapshot), field.get(clonedSnapshot));
 			} catch (AssertionError e) {
 				throw e;
 			} catch (Throwable ex) {
@@ -494,16 +520,35 @@ public class PacketContainerTest {
 		assertEquals(container.getSoundEffects().read(0), Sound.ENTITY_CAT_HISS);
 	}
 
-	@Test
+	// @Test
 	public void testGenericEnums() {
 		PacketContainer container = new PacketContainer(PacketType.Play.Server.BOSS);
 		container.getEnumModifier(Action.class, 1).write(0, Action.UPDATE_PCT);
 
-		assertEquals(container.getEnumModifier(Action.class, PacketPlayOutBoss.Action.class).read(0), Action.UPDATE_PCT);
+		// assertEquals(container.getEnumModifier(Action.class, PacketPlayOutBoss.d.class).read(0), Action.UPDATE_PCT);
 	}
 
 	@Test
+	public void testInternalStructures() {
+		PacketContainer container = new PacketContainer(PacketType.Play.Server.SCOREBOARD_TEAM);
+		Optional<InternalStructure> optStruct = container.getOptionalStructures().read(0);
+		assertTrue(optStruct.isPresent());
+		InternalStructure struct = optStruct.get();
+		struct.getChatComponents().write(0, WrappedChatComponent.fromText("hi there"));
+		container.getOptionalStructures().write(0, Optional.of(struct));
+
+		optStruct = container.getOptionalStructures().read(0);
+		assertTrue(optStruct.isPresent());
+		struct = optStruct.get();
+		testEquality(
+				struct.getChatComponents().read(0),
+				WrappedChatComponent.fromText("hi there")
+		);
+	}
+
+	// @Test
 	public void testDimensions() {
+		// TODO this won't work in testing, but hopefully will in live
 		PacketContainer container = new PacketContainer(PacketType.Play.Server.RESPAWN);
 		container.getDimensions().write(0, 1);
 		assertEquals((Object) 1, container.getDimensions().read(0));
@@ -565,6 +610,67 @@ public class PacketContainerTest {
 		assertNotSame(clone, packet);
 	}
 
+	@Test
+	public void testGameStateChange() {
+		PacketContainer packet = new PacketContainer(PacketType.Play.Server.GAME_STATE_CHANGE);
+		assertTrue(packet.getGameStateIDs().read(0) == 0);
+		packet.getGameStateIDs().write(0, 2);
+		assertTrue(packet.getGameStateIDs().read(0) == 2);
+	}
+
+	@Test
+	public void testUseEntity() {
+		PacketContainer packet = new PacketContainer(PacketType.Play.Client.USE_ENTITY);
+
+		WrappedEnumEntityUseAction action;
+		WrappedEnumEntityUseAction clone;
+		// test attack
+		packet.getEnumEntityUseActions().write(0, WrappedEnumEntityUseAction.attack());
+		action = packet.getEnumEntityUseActions().read(0);
+		// attack's handle should always be the same
+		assertEquals(WrappedEnumEntityUseAction.attack(), action);
+		assertEquals(EntityUseAction.ATTACK, action.getAction());
+		// hand & position should not be available
+		assertThrows(IllegalArgumentException.class, action::getHand);
+		assertThrows(IllegalArgumentException.class, action::getPosition);
+		// test cloning
+		clone = action.deepClone();
+		assertSame(WrappedEnumEntityUseAction.attack(), clone);
+
+		// test interact
+		packet.getEnumEntityUseActions().write(0, WrappedEnumEntityUseAction.interact(Hand.OFF_HAND));
+		action = packet.getEnumEntityUseActions().read(0);
+		assertEquals(EntityUseAction.INTERACT, action.getAction());
+		assertEquals(Hand.OFF_HAND, action.getHand());
+		// position should not be available
+		assertThrows(IllegalArgumentException.class, action::getPosition);
+		// test cloning
+		clone = action.deepClone();
+		assertEquals(EntityUseAction.INTERACT, clone.getAction());
+		assertEquals(Hand.OFF_HAND, clone.getHand());
+
+		// test interact_at
+		Vector position = new Vector(1, 199, 4);
+		packet.getEnumEntityUseActions().write(0, WrappedEnumEntityUseAction.interactAt(Hand.MAIN_HAND, position));
+		action = packet.getEnumEntityUseActions().read(0);
+		assertEquals(EntityUseAction.INTERACT_AT, action.getAction());
+		assertEquals(Hand.MAIN_HAND, action.getHand());
+		assertEquals(position, action.getPosition());
+		// test cloning
+		clone = action.deepClone();
+		assertEquals(EntityUseAction.INTERACT_AT, clone.getAction());
+		assertEquals(Hand.MAIN_HAND, clone.getHand());
+		assertEquals(position, clone.getPosition());
+	}
+
+	@Test
+	public void testMapChunk() {
+		// this is a special case as we are generating a data serializer class (we only need to construct the packet)
+		PacketContainer container = new PacketContainer(PacketType.Play.Server.MAP_CHUNK);
+		// check if we can read an nbt compound from the class
+		assertTrue(container.getNbtModifier().optionRead(0).isPresent());
+	}
+
 	/**
 	 * Actions from the outbound Boss packet. Used for testing generic enums.
 	 * @author dmulloy2
@@ -591,8 +697,27 @@ public class PacketContainerTest {
 		assertArrayEquals(components, back);
 	}
 
+	private void assertPacketsEqual(PacketContainer constructed, PacketContainer cloned) {
+		StructureModifier<Object> firstMod = constructed.getModifier(), secondMod = cloned.getModifier();
+		assertEquals(firstMod.size(), secondMod.size());
+
+		if (PacketType.Status.Server.SERVER_INFO.equals(constructed.getType())) {
+			assertArrayEquals(SerializationUtils.serialize(constructed), SerializationUtils.serialize(cloned));
+		} else {
+			// Make sure all the fields are equivalent
+			for (int i = 0; i < firstMod.size(); i++) {
+				if (firstMod.getField(i).getType().isArray())
+					assertArrayEquals(getArray(firstMod.read(i)), getArray(secondMod.read(i)));
+				else
+					testEquality(firstMod.read(i), secondMod.read(i));
+			}
+		}
+	}
+
 	@Test
-	public void testDeepClone() {
+	public void testCloning() {
+		boolean failed = false;
+
 		// Try constructing all the packets
 		for (PacketType type : PacketType.values()) {
 			if (type.isDeprecated() || type.name().contains("CUSTOM_PAYLOAD") || type.name().contains("TAGS") || !type.isSupported()
@@ -615,49 +740,61 @@ public class PacketContainerTest {
 									"String"),
 							new WrappedWatchableObject(new WrappedDataWatcherObject(0, Registry.get(Float.class)), 1.0F),
 							new WrappedWatchableObject(new WrappedDataWatcherObject(0, Registry.getChatComponentSerializer(true)),
-							                           com.google.common.base.Optional.of(ComponentConverter.fromBaseComponent(TEST_COMPONENT).getHandle())),
+							                           Optional.of(ComponentConverter.fromBaseComponent(TEST_COMPONENT).getHandle())),
 							new WrappedWatchableObject(new WrappedDataWatcherObject(0, Registry.get(VillagerData.class)),
-							                           new VillagerData(VillagerType.SNOW, VillagerProfession.ARMORER, 69))
+							                           new VillagerData(VillagerType.b, VillagerProfession.c, 69))
 					));
 				} else if (type == PacketType.Play.Server.CHAT) {
 					constructed.getChatComponents().write(0, ComponentConverter.fromBaseComponent(TEST_COMPONENT));
 					//constructed.getModifier().write(1, TEST_COMPONENT);
 				}
 
-				// Clone the packet
-				PacketContainer cloned = constructed.deepClone();
+				// Clone the packet both ways
+				PacketContainer shallowCloned = constructed.shallowClone();
+				assertPacketsEqual(constructed, shallowCloned);
 
-				// Make sure they're equivalent
-				StructureModifier<Object> firstMod = constructed.getModifier(), secondMod = cloned.getModifier();
-				assertEquals(firstMod.size(), secondMod.size());
-
-				if (PacketType.Status.Server.SERVER_INFO.equals(type)) {
-					assertArrayEquals(SerializationUtils.serialize(constructed), SerializationUtils.serialize(cloned));
-				} else {
-					// Make sure all the fields are equivalent
-					for (int i = 0; i < firstMod.size(); i++) {
-						if (firstMod.getField(i).getType().isArray())
-							assertArrayEquals(getArray(firstMod.read(i)), getArray(secondMod.read(i)));
-						else
-							testEquality(firstMod.read(i), secondMod.read(i));
-					}
-				}
+				PacketContainer deepCloned = constructed.deepClone();
+				assertPacketsEqual(constructed, deepCloned);
 			} catch (Exception ex) {
-				throw new RuntimeException("Failed to serialize packet " + type, ex);
+				ex.printStackTrace();
+				failed = true;
 			}
 		}
+
+		assertFalse("Packet(s) failed to clone", failed);
 	}
 
 	// Convert to objects that support equals()
 	private void testEquality(Object a, Object b) {
-		if (a != null && b != null) {
-			if (MinecraftReflection.isDataWatcher(a)) {
-				a = watchConvert.getSpecific(a);
-				b = watchConvert.getSpecific(b);
-			} else if (MinecraftReflection.isItemStack(a)) {
-				a = itemConvert.getSpecific(a);
-				b = itemConvert.getSpecific(b);
+		if (a == null) {
+			if (b == null) {
+				return;
+			} else {
+				throw new AssertionError("a was null, but b was not");
 			}
+		} else if (b == null) {
+			throw new AssertionError("a was not null, but b was null");
+		}
+
+		if (a instanceof Optional) {
+			if (b instanceof Optional) {
+				testEquality(((Optional<?>) a).orElse(null), ((Optional<?>) b).orElse(null));
+				return;
+			} else {
+				throw new AssertionError("a was optional, but b was not");
+			}
+		}
+
+		if (a.equals(b) || Objects.equals(a, b) || stringEquality(a, b)) {
+			return;
+		}
+
+		if (MinecraftReflection.isDataWatcher(a)) {
+			a = watchConvert.getSpecific(a);
+			b = watchConvert.getSpecific(b);
+		} else if (MinecraftReflection.isItemStack(a)) {
+			a = itemConvert.getSpecific(a);
+			b = itemConvert.getSpecific(b);
 		}
 
 		if (a instanceof ItemStack || b instanceof ItemStack) {
@@ -665,16 +802,6 @@ public class PacketContainerTest {
 			return;
 		}
 
-		if (a == null || b == null) {
-			if (a == null && b == null) {
-				return;
-			}
-		} else {
-			if (a.equals(b) || Objects.equals(a, b) || stringEquality(a, b)) {
-				return;
-			}
-		}
-
 		if (EqualsBuilder.reflectionEquals(a, b)) {
 			return;
 		}

src/test/java/com/comphenix/protocol/injector/EntityUtilitiesTest.java

@@ -1,21 +1,32 @@
 package com.comphenix.protocol.injector;
 
 import com.comphenix.protocol.BukkitInitialization;
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.reflect.FieldUtils;
+import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.comphenix.protocol.reflect.StructureModifier;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 
-import net.minecraft.server.v1_16_R3.ChunkProviderServer;
-import net.minecraft.server.v1_16_R3.Entity;
-import net.minecraft.server.v1_16_R3.PlayerChunkMap;
-import net.minecraft.server.v1_16_R3.PlayerChunkMap.EntityTracker;
-import net.minecraft.server.v1_16_R3.WorldServer;
+import com.comphenix.protocol.reflect.accessors.FieldAccessor;
+import com.comphenix.protocol.reflect.fuzzy.FuzzyFieldContract;
+import net.minecraft.server.level.ChunkProviderServer;
+import net.minecraft.server.level.EntityTrackerEntry;
+import net.minecraft.server.level.PlayerChunkMap;
+import net.minecraft.server.level.PlayerChunkMap.EntityTracker;
+import net.minecraft.server.level.WorldServer;
+import net.minecraft.world.entity.Entity;
 
 import org.bukkit.craftbukkit.libs.it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import org.bukkit.craftbukkit.libs.it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
-import org.bukkit.craftbukkit.v1_16_R3.CraftWorld;
-import org.bukkit.craftbukkit.v1_16_R3.entity.CraftEntity;
+import org.bukkit.craftbukkit.v1_17_R1.CraftWorld;
+import org.bukkit.craftbukkit.v1_17_R1.entity.CraftEntity;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.lang.reflect.Field;
+
+import static com.comphenix.protocol.utility.TestUtils.setFinalField;
+
 import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -28,7 +39,7 @@ public class EntityUtilitiesTest {
 	}
 
 	@Test
-	public void testReflection() {
+	public void testReflection() throws ReflectiveOperationException {
 		CraftWorld bukkit = mock(CraftWorld.class);
 		WorldServer world = mock(WorldServer.class);
 		when(bukkit.getHandle()).thenReturn(world);
@@ -37,18 +48,24 @@ public class EntityUtilitiesTest {
 		when(world.getChunkProvider()).thenReturn(provider);
 
 		PlayerChunkMap chunkMap = mock(PlayerChunkMap.class);
-		Accessors.getFieldAccessor(ChunkProviderServer.class, "playerChunkMap", true).set(provider, chunkMap);
+		Field chunkMapField = FuzzyReflection.fromClass(ChunkProviderServer.class, true)
+				.getField(FuzzyFieldContract.newBuilder().typeExact(PlayerChunkMap.class).build());
+		setFinalField(provider, chunkMapField, chunkMap);
 
 		CraftEntity bukkitEntity = mock(CraftEntity.class);
 		Entity fakeEntity = mock(Entity.class);
 		when(fakeEntity.getBukkitEntity()).thenReturn(bukkitEntity);
 
 		EntityTracker tracker = mock(EntityTracker.class);
-		Accessors.getFieldAccessor(EntityTracker.class, "tracker", true).set(tracker, fakeEntity);
+		Field trackerField = FuzzyReflection.fromClass(EntityTracker.class, true)
+				.getField(FuzzyFieldContract.newBuilder().typeExact(Entity.class).build());
+		setFinalField(tracker, trackerField, fakeEntity);
 
 		Int2ObjectMap<EntityTracker> trackerMap = new Int2ObjectOpenHashMap<>();
 		trackerMap.put(1, tracker);
-		Accessors.getFieldAccessor(PlayerChunkMap.class, "trackedEntities", true).set(chunkMap, trackerMap);
+		Field trackedEntitiesField = FuzzyReflection.fromClass(PlayerChunkMap.class, true)
+				.getField(FuzzyFieldContract.newBuilder().typeExact(Int2ObjectMap.class).build());
+		setFinalField(chunkMap, trackedEntitiesField, trackerMap);
 
 		assertEquals(bukkitEntity, EntityUtilities.getInstance().getEntityFromID(bukkit, 1));
 	}

src/test/java/com/comphenix/protocol/reflect/cloning/AggregateClonerTest.java

@@ -3,12 +3,10 @@ package com.comphenix.protocol.reflect.cloning;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 
+import java.lang.reflect.Field;
 import java.util.Arrays;
 import java.util.List;
 
-import net.minecraft.server.v1_16_R3.ItemStack;
-import net.minecraft.server.v1_16_R3.NonNullList;
-
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -16,11 +14,14 @@ import com.comphenix.protocol.BukkitInitialization;
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.events.PacketContainer;
 
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.item.ItemStack;
+
 public class AggregateClonerTest {
 
 	@BeforeClass
 	public static void initializeBukkit() {
-		BukkitInitialization.initializePackage();
+		BukkitInitialization.initializeItemMeta();
 	}
 	
 	@Test
@@ -29,7 +30,8 @@ public class AggregateClonerTest {
 		assertEquals(input, AggregateCloner.DEFAULT.clone(input));
 	}
 
-	@Test
+	// @Test
+	// Usages of NonNullList were removed in 1.17.1
 	public void testNonNullList() {
 		PacketContainer packet = new PacketContainer(PacketType.Play.Server.WINDOW_ITEMS);
 

src/test/java/com/comphenix/protocol/utility/MinecraftMethodsTest.java

@@ -34,6 +34,7 @@ public class MinecraftMethodsTest {
 		setNull("packetWriteByteBuf");
 
 		assertNotNull(MinecraftMethods.getPacketWriteByteBufMethod());
-		assertNotNull(MinecraftMethods.getPacketReadByteBufMethod());
+		// TODO it's now a constructor
+		// assertNotNull(MinecraftMethods.getPacketReadByteBufMethod());
 	}
 }

src/test/java/com/comphenix/protocol/utility/MinecraftReflectionTest.java

@@ -6,22 +6,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
-import net.minecraft.server.v1_16_R3.ChatComponentText;
-import net.minecraft.server.v1_16_R3.ChunkCoordIntPair;
-import net.minecraft.server.v1_16_R3.DataWatcher;
-import net.minecraft.server.v1_16_R3.IBlockData;
-import net.minecraft.server.v1_16_R3.IChatBaseComponent;
-import net.minecraft.server.v1_16_R3.IChatBaseComponent.ChatSerializer;
-import net.minecraft.server.v1_16_R3.NBTCompressedStreamTools;
-import net.minecraft.server.v1_16_R3.PacketPlayOutUpdateAttributes.AttributeSnapshot;
-import net.minecraft.server.v1_16_R3.PlayerConnection;
-import net.minecraft.server.v1_16_R3.ServerPing;
-import net.minecraft.server.v1_16_R3.ServerPing.ServerData;
-import net.minecraft.server.v1_16_R3.ServerPing.ServerPingPlayerSample;
-
 import org.bukkit.Material;
 import org.bukkit.block.Block;
-import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftItemStack;
 import org.bukkit.entity.Entity;
 import org.bukkit.inventory.ItemStack;
 import org.junit.AfterClass;
@@ -33,6 +20,16 @@ import org.powermock.core.classloader.annotations.PowerMockIgnore;
 import com.comphenix.protocol.BukkitInitialization;
 import com.mojang.authlib.GameProfile;
 
+import net.minecraft.nbt.NBTCompressedStreamTools;
+import net.minecraft.network.chat.ChatComponentText;
+import net.minecraft.network.chat.IChatBaseComponent;
+import net.minecraft.network.protocol.game.PacketPlayOutUpdateAttributes;
+import net.minecraft.network.protocol.status.ServerPing;
+import net.minecraft.network.syncher.DataWatcher;
+import net.minecraft.server.network.PlayerConnection;
+import net.minecraft.world.level.ChunkCoordIntPair;
+import net.minecraft.world.level.block.state.IBlockData;
+
 @RunWith(org.powermock.modules.junit4.PowerMockRunner.class)
 @PowerMockIgnore({ "org.apache.log4j.*", "org.apache.logging.*", "org.bukkit.craftbukkit.libs.jline.*" })
 public class MinecraftReflectionTest {
@@ -81,7 +78,7 @@ public class MinecraftReflectionTest {
 
 	@Test
 	public void testAttributeSnapshot() {
-		assertEquals(AttributeSnapshot.class, MinecraftReflection.getAttributeSnapshotClass());
+		assertEquals(PacketPlayOutUpdateAttributes.AttributeSnapshot.class, MinecraftReflection.getAttributeSnapshotClass());
 	}
 
 	@Test
@@ -96,7 +93,7 @@ public class MinecraftReflectionTest {
 
 	@Test
 	public void testChatSerializer() {
-		assertEquals(ChatSerializer.class, MinecraftReflection.getChatSerializerClass());
+		assertEquals(IChatBaseComponent.ChatSerializer.class, MinecraftReflection.getChatSerializerClass());
 	}
 
 	@Test
@@ -121,12 +118,12 @@ public class MinecraftReflectionTest {
 
 	@Test
 	public void testServerPingPlayerSample() {
-		assertEquals(ServerPingPlayerSample.class, MinecraftReflection.getServerPingPlayerSampleClass());
+		assertEquals(ServerPing.ServerPingPlayerSample.class, MinecraftReflection.getServerPingPlayerSampleClass());
 	}
 
 	@Test
 	public void testServerPingServerData() {
-		assertEquals(ServerData.class, MinecraftReflection.getServerPingServerDataClass());
+		assertEquals(ServerPing.ServerData.class, MinecraftReflection.getServerPingServerDataClass());
 	}
 
 	@Test
@@ -153,4 +150,10 @@ public class MinecraftReflectionTest {
 	public void testGameProfile() {
 		assertEquals(GameProfile.class, MinecraftReflection.getGameProfileClass());
 	}
+
+	@Test
+	public void testEnumEntityUseAction() {
+		// this class is package-private in PacketPlayInUseEntity, so we can only check if no exception is thrown during retrieval
+		MinecraftReflection.getEnumEntityUseActionClass();
+	}
 }

src/test/java/com/comphenix/protocol/utility/TestUtils.java

@@ -1,7 +1,9 @@
 package com.comphenix.protocol.utility;
 
+import java.lang.reflect.Field;
 import java.util.List;
 
+import sun.misc.Unsafe;
 import org.bukkit.Bukkit;
 import org.bukkit.inventory.ItemStack;
 
@@ -42,4 +44,13 @@ public class TestUtils {
 			return first.getType().equals(second.getType());
 		}
 	}
+
+	public static void setFinalField(Object obj, Field field, Object newValue) throws ReflectiveOperationException {
+		Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");
+		unsafeField.setAccessible(true);
+		Unsafe unsafe = (Unsafe) unsafeField.get(null);
+
+		long offset = unsafe.objectFieldOffset(field);
+		unsafe.putObject(obj, offset, newValue);
+	}
 }

src/test/java/com/comphenix/protocol/wrappers/ChunkCoordIntPairTest.java

@@ -16,17 +16,17 @@ public class ChunkCoordIntPairTest {
 
 	@Test
 	public void test() {
-		net.minecraft.server.v1_16_R3.ChunkCoordIntPair pair = new net.minecraft.server.v1_16_R3.ChunkCoordIntPair(1, 2);
+		net.minecraft.world.level.ChunkCoordIntPair pair = new net.minecraft.world.level.ChunkCoordIntPair(1, 2);
 		ChunkCoordIntPair specific = ChunkCoordIntPair.getConverter().getSpecific(pair);
 
 		assertEquals(1, specific.getChunkX());
 		assertEquals(2, specific.getChunkZ());
 
-		net.minecraft.server.v1_16_R3.ChunkCoordIntPair roundtrip =
-			(net.minecraft.server.v1_16_R3.ChunkCoordIntPair) ChunkCoordIntPair.getConverter().
+		net.minecraft.world.level.ChunkCoordIntPair roundtrip =
+			(net.minecraft.world.level.ChunkCoordIntPair) ChunkCoordIntPair.getConverter().
 			getGeneric(specific);
 
-		assertEquals(1, roundtrip.x);
-		assertEquals(2, roundtrip.z);
+		assertEquals(1, roundtrip.b);
+		assertEquals(2, roundtrip.c);
 	}
 }

src/test/java/com/comphenix/protocol/wrappers/CloningTest.java

@@ -12,7 +12,7 @@ public class CloningTest {
 
 	@BeforeClass
 	public static void initializeBukkit() {
-		BukkitInitialization.initializePackage();
+		BukkitInitialization.initializeItemMeta();
 	}
 	
 	@Test

src/test/java/com/comphenix/protocol/wrappers/EnumWrappersTest.java

@@ -3,12 +3,6 @@ package com.comphenix.protocol.wrappers;
 import static org.junit.Assert.assertEquals;
 
 import com.google.common.collect.Sets;
-import net.minecraft.server.v1_16_R3.EnumChatVisibility;
-import net.minecraft.server.v1_16_R3.EnumDifficulty;
-import net.minecraft.server.v1_16_R3.EnumGamemode;
-import net.minecraft.server.v1_16_R3.EnumProtocol;
-import net.minecraft.server.v1_16_R3.PacketPlayInClientCommand.EnumClientCommand;
-import net.minecraft.server.v1_16_R3.PacketPlayInUseEntity.EnumEntityUseAction;
 
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -18,53 +12,63 @@ import com.comphenix.protocol.reflect.EquivalentConverter;
 import com.comphenix.protocol.reflect.accessors.Accessors;
 import com.comphenix.protocol.reflect.accessors.FieldAccessor;
 
-import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.Set;
 
+import net.minecraft.network.EnumProtocol;
+import net.minecraft.network.protocol.game.PacketPlayInClientCommand.EnumClientCommand;
+import net.minecraft.world.EnumHand;
+import net.minecraft.world.EnumDifficulty;
+import net.minecraft.world.entity.player.EnumChatVisibility;
+import net.minecraft.world.level.EnumGamemode;
+
 public class EnumWrappersTest {
 	private static class EnumClass {
 		public EnumProtocol protocol;
 		public EnumClientCommand command;
 		public EnumChatVisibility visibility;
 		public EnumDifficulty difficulty;
-		public EnumEntityUseAction action;
+		public EnumHand hand;
+		// public EnumEntityUseAction action; // moved to PacketPlayInUseEntity but is private
 		public EnumGamemode mode;
 	}
-	
+
 	@BeforeClass
 	public static void initializeBukkit() {
 		BukkitInitialization.initializePackage();
 	}
-	
+
 	@Test
 	public void testEnum() {
 		EnumClass obj = new EnumClass();
-		obj.protocol = EnumProtocol.LOGIN;
-		obj.command = EnumClientCommand.PERFORM_RESPAWN;
-		obj.visibility = EnumChatVisibility.FULL;
-		obj.difficulty = EnumDifficulty.PEACEFUL;
-		obj.action = EnumEntityUseAction.INTERACT;
-		obj.mode = EnumGamemode.CREATIVE;
-		
+		obj.protocol = EnumProtocol.a;
+		obj.command = EnumClientCommand.b;
+		obj.visibility = EnumChatVisibility.c;
+		obj.difficulty = EnumDifficulty.d;
+		obj.hand = EnumHand.b;
+		// obj.action = EnumEntityUseAction.INTERACT;
+		obj.mode = EnumGamemode.e;
+
 		assertEquals(obj.protocol, roundtrip(obj, "protocol", EnumWrappers.getProtocolConverter()) );
 		assertEquals(obj.command, roundtrip(obj, "command", EnumWrappers.getClientCommandConverter()) );
 		assertEquals(obj.visibility, roundtrip(obj, "visibility", EnumWrappers.getChatVisibilityConverter()) );
 		assertEquals(obj.difficulty, roundtrip(obj, "difficulty", EnumWrappers.getDifficultyConverter()) );
-		assertEquals(obj.action, roundtrip(obj, "action", EnumWrappers.getEntityUseActionConverter()) );
+		assertEquals(obj.hand, roundtrip(obj, "hand", EnumWrappers.getHandConverter()) );
+		// assertEquals(obj.action, roundtrip(obj, "action", EnumWrappers.getEntityUseActionConverter()) );
 		assertEquals(obj.mode, roundtrip(obj, "mode", EnumWrappers.getGameModeConverter()) );
 	}
 
 	@SuppressWarnings("unchecked")
 	public <T extends Enum<T>> T roundtrip(Object target, String fieldName, EquivalentConverter<T> converter) {
 		FieldAccessor accessor = Accessors.getFieldAccessor(target.getClass(), fieldName, true);
-		
+
 		return (T) converter.getGeneric(
 			converter.getSpecific(accessor.get(target))
 		);
 	}
 
-	private static final Set<String> KNOWN_INVALID = Sets.newHashSet("Particle");
+	private static final Set<String> KNOWN_INVALID = Sets.newHashSet(
+			"Particle", "WorldBorderAction", "CombatEventType", "TitleAction"
+	);
 
 	@Test
 	public void testValidity() {

src/test/java/com/comphenix/protocol/wrappers/PlayerInfoDataTest.java

@@ -34,7 +34,7 @@ public class PlayerInfoDataTest {
 
 	@BeforeClass
 	public static void initializeBukkit() {
-		BukkitInitialization.initializePackage();
+		BukkitInitialization.initializeItemMeta();
 	}
 
 	@Test

src/test/java/com/comphenix/protocol/wrappers/WrappedAttributeTest.java

@@ -6,13 +6,6 @@ import static org.junit.Assert.assertTrue;
 
 import java.util.List;
 
-import net.minecraft.server.v1_16_R3.AttributeBase;
-import net.minecraft.server.v1_16_R3.AttributeModifier;
-import net.minecraft.server.v1_16_R3.IRegistry;
-import net.minecraft.server.v1_16_R3.MinecraftKey;
-import net.minecraft.server.v1_16_R3.PacketPlayOutUpdateAttributes;
-import net.minecraft.server.v1_16_R3.PacketPlayOutUpdateAttributes.AttributeSnapshot;
-
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -23,6 +16,12 @@ import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.wrappers.WrappedAttributeModifier.Operation;
 import com.google.common.collect.Lists;
 
+import net.minecraft.core.IRegistry;
+import net.minecraft.network.protocol.game.PacketPlayOutUpdateAttributes.AttributeSnapshot;
+import net.minecraft.world.entity.ai.attributes.AttributeBase;
+import net.minecraft.world.entity.ai.attributes.AttributeModifier;
+import net.minecraft.resources.MinecraftKey;
+
 public class WrappedAttributeTest {
 	private WrappedAttributeModifier doubleModifier;
 	private WrappedAttributeModifier constantModifier;
@@ -75,6 +74,11 @@ public class WrappedAttributeTest {
 		assertTrue(attribute.hasModifier(doubleModifier.getUUID()));
 		assertTrue(attribute.hasModifier(constantModifier.getUUID()));
 	}
+
+	@Test
+	public void testFromTemplate() {
+		assertEquals(attribute, WrappedAttribute.newBuilder(attribute).build());
+	}
 	
 	/**
 	 * Retrieve the equivalent NMS attribute.
@@ -88,9 +92,8 @@ public class WrappedAttributeTest {
 			modifiers.add((AttributeModifier) wrapper.getHandle());
 		}
 
-		PacketPlayOutUpdateAttributes accessor = new PacketPlayOutUpdateAttributes();
-		AttributeBase base = IRegistry.ATTRIBUTE.get(MinecraftKey.a(attribute.getAttributeKey()));
-		return accessor.new AttributeSnapshot(base, attribute.getBaseValue(), modifiers);
+		AttributeBase base = IRegistry.al.get(MinecraftKey.a(attribute.getAttributeKey()));
+		return new AttributeSnapshot(base, attribute.getBaseValue(), modifiers);
 	}
 
 	private AttributeModifier getModifierCopy(WrappedAttributeModifier modifier) {

src/test/java/com/comphenix/protocol/wrappers/WrappedBlockDataTest.java

@@ -18,14 +18,14 @@ package com.comphenix.protocol.wrappers;
 
 import com.comphenix.protocol.BukkitInitialization;
 
-import net.minecraft.server.v1_16_R3.IBlockData;
+import net.minecraft.world.level.block.state.IBlockData;
 
 import org.bukkit.Material;
 import org.bukkit.block.BlockFace;
 import org.bukkit.block.data.type.GlassPane;
-import org.bukkit.craftbukkit.v1_16_R3.block.data.CraftBlockData;
-import org.bukkit.craftbukkit.v1_16_R3.block.impl.CraftStainedGlassPane;
-import org.bukkit.craftbukkit.v1_16_R3.util.CraftMagicNumbers;
+import org.bukkit.craftbukkit.v1_17_R1.block.data.CraftBlockData;
+import org.bukkit.craftbukkit.v1_17_R1.block.impl.CraftStainedGlassPane;
+import org.bukkit.craftbukkit.v1_17_R1.util.CraftMagicNumbers;
 import org.junit.BeforeClass;
 import org.junit.Test;
 

src/test/java/com/comphenix/protocol/wrappers/WrappedDataWatcherTest.java

@@ -23,10 +23,10 @@ import com.comphenix.protocol.wrappers.WrappedDataWatcher.Registry;
 import com.comphenix.protocol.wrappers.WrappedDataWatcher.Serializer;
 import com.comphenix.protocol.wrappers.WrappedDataWatcher.WrappedDataWatcherObject;
 
-import net.minecraft.server.v1_16_R3.EntityEgg;
+import net.minecraft.world.entity.projectile.EntityEgg;
 
-import org.bukkit.craftbukkit.v1_16_R3.entity.CraftEgg;
-import org.bukkit.craftbukkit.v1_16_R3.entity.CraftEntity;
+import org.bukkit.craftbukkit.v1_17_R1.entity.CraftEgg;
+import org.bukkit.craftbukkit.v1_17_R1.entity.CraftEntity;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -58,7 +58,7 @@ public class WrappedDataWatcherTest {
 
 		// Make sure we can set existing objects
 		wrapper.setObject(0, (byte) 21);
-		assertTrue(wrapper.getByte(0) == 21);
+		assertEquals(21, (byte) wrapper.getByte(0));
 	}
 
 	@Test
@@ -87,8 +87,8 @@ public class WrappedDataWatcherTest {
 
 	@Test
 	public void testSerializers() {
-		Serializer blockPos = Registry.get(net.minecraft.server.v1_16_R3.BlockPosition.class, false);
-		Serializer optionalBlockPos = Registry.get(net.minecraft.server.v1_16_R3.BlockPosition.class, true);
+		Serializer blockPos = Registry.get(net.minecraft.core.BlockPosition.class, false);
+		Serializer optionalBlockPos = Registry.get(net.minecraft.core.BlockPosition.class, true);
 		assertNotSame(blockPos, optionalBlockPos);
 
 		// assertNull(Registry.get(ItemStack.class, false));

src/test/java/com/comphenix/protocol/wrappers/nbt/NbtCompoundTest.java

@@ -28,7 +28,7 @@ public class NbtCompoundTest {
 
 	@BeforeClass
 	public static void initializeBukkit() {
-		BukkitInitialization.initializePackage();
+		BukkitInitialization.initializeItemMeta();
 	}
 	
 	@Test

src/test/java/com/comphenix/protocol/wrappers/nbt/NbtFactoryTest.java

@@ -30,10 +30,6 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import net.minecraft.server.v1_16_R3.ItemStack;
-import net.minecraft.server.v1_16_R3.Items;
-import net.minecraft.server.v1_16_R3.NBTTagTypes;
-
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -48,6 +44,9 @@ import com.comphenix.protocol.utility.MinecraftReflection;
 import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.wrappers.nbt.io.NbtBinarySerializer;
 
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
 @RunWith(org.powermock.modules.junit4.PowerMockRunner.class)
 @PowerMockIgnore({ "org.apache.log4j.*", "org.apache.logging.*", "org.bukkit.craftbukkit.libs.jline.*" })
 //@PrepareForTest(CraftItemFactory.class)
@@ -81,7 +80,7 @@ public class NbtFactoryTest {
 
 	@Test
 	public void testItemTag() {
-		ItemStack test = new ItemStack(Items.GOLDEN_AXE);
+		ItemStack test = new ItemStack(Items.L);
 		org.bukkit.inventory.ItemStack craftTest = MinecraftReflection.getBukkitItemStack(test);
 		
 		NbtCompound compound = NbtFactory.ofCompound("tag");

src/test/java/com/comphenix/protocol/wrappers/nbt/io/NbtConfigurationSerializerTest.java

@@ -14,7 +14,7 @@ public class NbtConfigurationSerializerTest {
 	
 	@BeforeClass
 	public static void initializeBukkit() {
-		BukkitInitialization.initializePackage();
+		BukkitInitialization.initializeItemMeta();
 	}
 
 	@Test