Bump version to 0.4.9

Fix some MalformedJsonExceptions

README.md

@@ -1,18 +1,10 @@
-# ViaVersion 0.4.6
+# ViaVersion 0.4.9
 **Allows the connection of 1.8 clients to 1.9**
 
 This plugin modifies netty to allow connection of 1.9 clients to 1.8,
 
 **Don't use late bind*
 
-**As of this point it doesn't have everything, I need to fix:**
-
-Attempt to make boats nicer when they don't work
-
-Remap spawn eggs
-
-If you have a bug with entities, please report the full stack trace
-
 
 This took hours of work, so if you enjoy this consider looking into contacting me and supporting my projects.
 
@@ -24,6 +16,10 @@ Sources:
 
 **MCProtocolLib** (used for chunk reading & some of writing.)
 
+**OpenNBT** (used for slot rewriting)
+
+
+
 Contributors:
 --------
 
@@ -33,6 +29,7 @@ Contributors:
 **SanderGielisse**
 **Paulomart**
 **gigosaurus**
+**fillefilip8**
 
 **Chat: ** https://gitter.im/MylesIsCool/ViaVersion
 

pom.xml

@@ -1,14 +1,30 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>us.myles</groupId>
     <artifactId>ViaVersion</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <version>0.4.9</version>
     <build>
+        <finalName>ViaVersion-${version}</finalName>
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>1.4</version>
+                <configuration>
+                    <createDependencyReducedPom>false</createDependencyReducedPom>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
@@ -18,8 +34,19 @@
                 </configuration>
             </plugin>
         </plugins>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
     </build>
     <dependencies>
+        <dependency>
+            <groupId>org.spacehq</groupId>
+            <artifactId>opennbt</artifactId>
+            <version>1.0</version>
+        </dependency>
         <dependency>
             <groupId>org.bukkit</groupId>
             <artifactId>bukkit</artifactId>
@@ -50,5 +77,9 @@
             <id>spigot-repo</id>
             <url>https://hub.spigotmc.org/nexus/content/repositories/snapshots/</url>
         </repository>
-   </repositories>
+        <repository>
+            <id>spacehq-repo</id>
+            <url>https://repo.spacehq.org/content/repositories/releases/</url>
+        </repository>
+    </repositories>
 </project>

src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -12,12 +12,13 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.java.JavaPlugin;
-
 import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.ViaVersionAPI;
+import us.myles.ViaVersion.commands.ViaVersionCommand;
 import us.myles.ViaVersion.handlers.ViaVersionInitializer;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.lang.reflect.Field;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
@@ -33,12 +34,12 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
     @Override
     public void onEnable() {
         ViaVersion.setInstance(this);
-        if(System.getProperty("ViaVersion") != null){
+        if (System.getProperty("ViaVersion") != null) {
             getLogger().severe("ViaVersion is already loaded, we don't support reloads. Please reboot if you wish to update.");
             return;
         }
 
-        getLogger().info("ViaVersion enabled, injecting. (Allows 1.8 to be accessed via 1.9)");
+        getLogger().info("ViaVersion " + getDescription().getVersion() + " is now enabled, injecting. (Allows 1.8 to be accessed via 1.9)");
         try {
             injectPacketHandler();
             System.setProperty("ViaVersion", getDescription().getVersion());
@@ -52,24 +53,36 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
                 setPorted(e.getPlayer().getUniqueId(), false);
             }
         }, this);
+        getCommand("viaversion").setExecutor(new ViaVersionCommand());
     }
 
     public void injectPacketHandler() throws Exception {
         Class<?> serverClazz = ReflectionUtil.nms("MinecraftServer");
         Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
         Object connection = serverClazz.getDeclaredMethod("getServerConnection").invoke(server);
-
-        List<ChannelFuture> futures = ReflectionUtil.get(connection, "g", List.class);
-        if (futures.size() == 0) {
-            throw new Exception("Could not find server to inject (Please ensure late-bind in your spigot.yml is false)");
+        // loop through all fields checking if list
+        boolean injected = false;
+        for (Field field : connection.getClass().getDeclaredFields()) {
+            field.setAccessible(true);
+            Object value = field.get(connection);
+            if (value instanceof List) {
+                for (Object o : (List) value) {
+                    if (o instanceof ChannelFuture) {
+                        ChannelFuture future = (ChannelFuture) o;
+                        ChannelPipeline pipeline = future.channel().pipeline();
+                        ChannelHandler bootstrapAcceptor = pipeline.first();
+                        ChannelInitializer<SocketChannel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
+                        ChannelInitializer newInit = new ViaVersionInitializer(oldInit);
+                        ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
+                        injected = true;
+                    } else {
+                        break; // not the right list.
+                    }
+                }
+            }
         }
-
-        for (ChannelFuture future : futures) {
-            ChannelPipeline pipeline = future.channel().pipeline();
-            ChannelHandler bootstrapAcceptor = pipeline.first();
-            ChannelInitializer<SocketChannel> oldInit = ReflectionUtil.get(bootstrapAcceptor, "childHandler", ChannelInitializer.class);
-            ChannelInitializer newInit = new ViaVersionInitializer(oldInit);
-            ReflectionUtil.set(bootstrapAcceptor, "childHandler", newInit);
+        if (!injected) {
+            throw new Exception("Could not find server to inject (Please ensure late-bind in your spigot.yml is false)");
         }
     }
 
@@ -78,6 +91,11 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         return portedPlayers.contains(player.getUniqueId());
     }
 
+    @Override
+    public String getVersion() {
+        return getDescription().getVersion();
+    }
+
     public void setPorted(UUID id, boolean value) {
         if (value) {
             portedPlayers.add(id);

src/main/java/us/myles/ViaVersion/api/ViaVersionAPI.java

@@ -3,6 +3,11 @@ package us.myles.ViaVersion.api;
 import org.bukkit.entity.Player;
 
 public interface ViaVersionAPI {
-
+    /**
+     * Is player using 1.9?
+     * @param player
+     * @return
+     */
     boolean isPorted(Player player);
+    String getVersion();
 }

src/main/java/us/myles/ViaVersion/commands/ViaVersionCommand.java

@@ -0,0 +1,48 @@
+package us.myles.ViaVersion.commands;
+
+import org.bukkit.Bukkit;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import us.myles.ViaVersion.api.ViaVersion;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by fillefilip8 on 2016-03-03.
+ */
+public class ViaVersionCommand implements CommandExecutor {
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
+        if (sender.hasPermission("viaversion.admin")) {
+            if (args.length == 0) {
+                sender.sendMessage(color("&aViaVersion &c" + ViaVersion.getInstance().getVersion()));
+                sender.sendMessage(color("&6Commands:"));
+                sender.sendMessage(color("&2/viaversion list &7- &6Shows lists of all 1.9 clients and 1.8 clients."));
+            } else if (args.length == 1) {
+                if (args[0].equalsIgnoreCase("list")) {
+                    List<String> portedPlayers = new ArrayList<String>();
+                    List<String> normalPlayers = new ArrayList<String>();
+                    for (Player p : Bukkit.getOnlinePlayers()) {
+                        if (ViaVersion.getInstance().isPorted(p)) {
+                            portedPlayers.add(p.getName());
+                        } else {
+                            normalPlayers.add(p.getName());
+                        }
+                    }
+
+                    sender.sendMessage(color("&8[&61.9&8]: &b" + portedPlayers.toString()));
+                    sender.sendMessage(color("&8[&61.8&8]: &b" + normalPlayers.toString()));
+                }
+            }
+
+        }
+        return false;
+    }
+    public String color(String string){
+        return string.replace("&", "§");
+    }
+}

src/main/java/us/myles/ViaVersion/handlers/ViaDecodeHandler.java

@@ -31,6 +31,7 @@ public class ViaDecodeHandler extends ByteToMessageDecoder {
                 ByteBuf newPacket = ctx.alloc().buffer();
                 try {
                     incomingTransformer.transform(id, bytebuf, newPacket);
+                    bytebuf.readBytes(bytebuf.readableBytes());
                     bytebuf = newPacket;
                 } catch (CancelException e) {
                     bytebuf.readBytes(bytebuf.readableBytes());
@@ -44,13 +45,7 @@ public class ViaDecodeHandler extends ByteToMessageDecoder {
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        if (!(cause.getCause().getCause() instanceof CancelException)) {
-            if (!(cause.getCause() instanceof CancelException)) {
-                if (!(cause instanceof CancelException)) {
-                    super.exceptionCaught(ctx, cause);
-                }
-            }
-        }
+        if (PacketUtil.containsCause(cause, CancelException.class)) return;
+        super.exceptionCaught(ctx, cause);
     }
-
 }

src/main/java/us/myles/ViaVersion/handlers/ViaEncodeHandler.java

@@ -72,12 +72,7 @@ public class ViaEncodeHandler extends MessageToByteEncoder {
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-        if (!(cause.getCause().getCause() instanceof CancelException)) {
-            if (!(cause.getCause() instanceof CancelException)) {
-                if (!(cause instanceof CancelException)) {
-                    super.exceptionCaught(ctx, cause);
-                }
-            }
-        }
+        if (PacketUtil.containsCause(cause, CancelException.class)) return;
+        super.exceptionCaught(ctx, cause);
     }
 }

src/main/java/us/myles/ViaVersion/metadata/MetaIndex.java

@@ -27,10 +27,10 @@ public enum MetaIndex {
     STAND_LL_POS(ArmorStand.class, 15, Type.Rotation, NewType.Vector3F),
     STAND_RL_POS(ArmorStand.class, 16, Type.Rotation, NewType.Vector3F),
     // human, discountined?
-    PLAYER_SKIN_FLAGS(HumanEntity.class, 10, Type.Byte, NewType.Discontinued), // unsigned on 1.8
+    PLAYER_SKIN_FLAGS(HumanEntity.class, 10, Type.Byte, 12, NewType.Byte), // unsigned on 1.8
     PLAYER_HUMAN_BYTE(HumanEntity.class, 16, Type.Byte, NewType.Discontinued), // unused on 1.8
-    PLAYER_ADDITIONAL_HEARTS(HumanEntity.class, 17, Type.Float, NewType.Discontinued),
-    PLAYER_SCORE(HumanEntity.class, 18, Type.Int, NewType.Discontinued),
+    PLAYER_ADDITIONAL_HEARTS(HumanEntity.class, 17, Type.Float, 10, NewType.Float),
+    PLAYER_SCORE(HumanEntity.class, 18, Type.Int, 11, NewType.VarInt),
     // horse
     HORSE_INFO(Horse.class, 16, Type.Int, 12, NewType.Byte),
     HORSE_TYPE(Horse.class, 19, Type.Byte, 13, NewType.VarInt),

src/main/java/us/myles/ViaVersion/metadata/MetadataRewriter.java

@@ -11,6 +11,8 @@ import org.bukkit.util.Vector;
 
 import io.netty.buffer.ByteBuf;
 
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
+import us.myles.ViaVersion.slot.ItemSlotRewriter.ItemStack;
 import us.myles.ViaVersion.util.PacketUtil;
 
 public class MetadataRewriter {
@@ -92,7 +94,9 @@ public class MetadataRewriter {
                                 output.writeBoolean(((Byte) value).byteValue() != 0);
                             break;
                         case Slot:
-                            PacketUtil.writeItem(value, output);
+                            ItemStack item = (ItemStack) value;
+                            ItemSlotRewriter.fixIdsFrom1_8To1_9(item);
+                            ItemSlotRewriter.writeItemStack(item, output);
                             break;
                         case Position:
                             Vector vector = (Vector) value;
@@ -148,8 +152,13 @@ public class MetadataRewriter {
                 case String:
                     entries.add(new Entry(index, PacketUtil.readString(buf)));
                     break;
-                case Slot:
-                    entries.add(new Entry(index, PacketUtil.readItem(buf)));
+                case Slot: {
+                    try {
+                        entries.add(new Entry(index, ItemSlotRewriter.readItemStack(buf)));
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
                     break;
                 case Position: {
                     int x = buf.readInt();

src/main/java/us/myles/ViaVersion/slot/ItemSlotRewriter.java

@@ -0,0 +1,296 @@
+package us.myles.ViaVersion.slot;
+
+import io.netty.buffer.ByteBuf;
+import org.bukkit.Material;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
+import org.spacehq.opennbt.tag.builtin.StringTag;
+import us.myles.ViaVersion.CancelException;
+import us.myles.ViaVersion.util.PacketUtil;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ItemSlotRewriter {
+
+    public static void rewrite1_9To1_8(ByteBuf input, ByteBuf output) throws CancelException {
+        try {
+            ItemStack item = readItemStack(input);
+            fixIdsFrom1_9To1_8(item);
+            writeItemStack(item, output);
+        } catch (Exception e) {
+            System.out.println("Error while rewriting an item slot.");
+            e.printStackTrace();
+            throw new CancelException();
+        }
+    }
+
+    public static void rewrite1_8To1_9(ByteBuf input, ByteBuf output) throws CancelException {
+        try {
+            ItemStack item = readItemStack(input);
+            fixIdsFrom1_8To1_9(item);
+            writeItemStack(item, output);
+        } catch (Exception e) {
+            System.out.println("Error while rewriting an item slot.");
+            e.printStackTrace();
+            throw new CancelException();
+        }
+    }
+
+    public static void fixIdsFrom1_9To1_8(ItemStack item) {
+        if (item != null) {
+            if (item.id == Material.MONSTER_EGG.getId() && item.data == 0) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                if (tag != null && tag.get("EntityTag") instanceof CompoundTag) {
+                    CompoundTag entityTag = tag.get("EntityTag");
+                    if (entityTag.get("id") instanceof StringTag) {
+                        StringTag id = entityTag.get("id");
+                        if (ENTTIY_NAME_TO_ID.containsKey(id.getValue()))
+                            data = ENTTIY_NAME_TO_ID.get(id.getValue());
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName);
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+            if (item.id == 438) {
+                CompoundTag tag = item.tag;
+                int data = 0;
+                item.id = (short) Material.POTION.getId();
+                if (tag != null && tag.get("Potion") instanceof StringTag) {
+                    StringTag potion = tag.get("Potion");
+                    String potionName = potion.getValue().replace("minecraft:", "");
+                    if (POTION_NAME_TO_ID.containsKey(potionName)) {
+                        data = POTION_NAME_TO_ID.get(potionName) + 8192;
+                    }
+                }
+                item.tag = null;
+                item.data = (short) data;
+            }
+        }
+    }
+
+    public static void fixIdsFrom1_8To1_9(ItemStack item) {
+        if (item != null) {
+            if (item.id == Material.MONSTER_EGG.getId() && item.data != 0) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                CompoundTag entityTag = new CompoundTag("EntityTag");
+                if (ENTTIY_ID_TO_NAME.containsKey(Integer.valueOf(item.data))) {
+                    StringTag id = new StringTag("id", ENTTIY_ID_TO_NAME.get(Integer.valueOf(item.data)));
+                    entityTag.put(id);
+                    tag.put(entityTag);
+                }
+                item.tag = tag;
+                item.data = 0;
+            }
+            if (item.id == Material.POTION.getId()) {
+                CompoundTag tag = item.tag;
+                if (tag == null) {
+                    tag = new CompoundTag("tag");
+                }
+                if(item.data >= 16384){
+                    item.id = 438; // splash id
+                    item.data = (short) (item.data - 8192);
+                }
+                if (POTION_ID_TO_NAME.containsKey(Integer.valueOf(item.data))) {
+                    String name = POTION_ID_TO_NAME.get(Integer.valueOf(item.data));
+                    StringTag potion = new StringTag("Potion", "minecraft:" + name);
+                    tag.put(potion);
+                }
+                item.tag = tag;
+                item.data = 0;
+            }
+        }
+    }
+
+    public static ItemStack readItemStack(ByteBuf input) throws IOException {
+        short id = input.readShort();
+        if (id < 0) {
+            return null;
+        } else {
+            ItemStack item = new ItemStack();
+            item.id = id;
+            item.amount = input.readByte();
+            item.data = input.readShort();
+            item.tag = PacketUtil.readNBT(input);
+            return item;
+        }
+    }
+
+    public static void writeItemStack(ItemStack item, ByteBuf output) throws IOException {
+        if (item == null) {
+            output.writeShort(-1);
+        } else {
+            output.writeShort(item.id);
+            output.writeByte(item.amount);
+            output.writeShort(item.data);
+            PacketUtil.writeNBT(output, item.tag);
+        }
+    }
+
+    public static class ItemStack {
+
+        private short id;
+        private byte amount;
+        private short data;
+        private CompoundTag tag;
+
+        public static ItemStack fromBukkit(org.bukkit.inventory.ItemStack stack) {
+            ItemStack item = new ItemStack();
+            item.id = (short) stack.getTypeId();
+            item.amount = (byte) stack.getAmount();
+            item.data = stack.getData().getData();
+            // TODO: nbt
+            return item;
+        }
+    }
+
+    private static Map<String, Integer> ENTTIY_NAME_TO_ID = new HashMap<>();
+    private static Map<Integer, String> ENTTIY_ID_TO_NAME = new HashMap<>();
+
+    private static Map<String, Integer> POTION_NAME_TO_ID = new HashMap<>();
+    private static Map<Integer, String> POTION_ID_TO_NAME = new HashMap<>();
+
+    static {
+        /* Entities */
+        registerEntity(1, "Item");
+        registerEntity(2, "XPOrb");
+        registerEntity(7, "ThrownEgg");
+        registerEntity(8, "LeashKnot");
+        registerEntity(9, "Painting");
+        registerEntity(10, "Arrow");
+        registerEntity(11, "Snowball");
+        registerEntity(12, "Fireball");
+        registerEntity(13, "SmallFireball");
+        registerEntity(14, "ThrownEnderpearl");
+        registerEntity(15, "EyeOfEnderSignal");
+        registerEntity(16, "ThrownPotion");
+        registerEntity(17, "ThrownExpBottle");
+        registerEntity(18, "ItemFrame");
+        registerEntity(19, "WitherSkull");
+        registerEntity(20, "PrimedTnt");
+        registerEntity(21, "FallingSand");
+        registerEntity(22, "FireworksRocketEntity");
+        registerEntity(30, "ArmorStand");
+        registerEntity(40, "MinecartCommandBlock");
+        registerEntity(41, "Boat");
+        registerEntity(42, "MinecartRideable");
+        registerEntity(43, "MinecartChest");
+        registerEntity(44, "MinecartFurnace");
+        registerEntity(45, "MinecartTNT");
+        registerEntity(46, "MinecartHopper");
+        registerEntity(47, "MinecartSpawner");
+        registerEntity(48, "Mob");
+        registerEntity(49, "Monster");
+        registerEntity(50, "Creeper");
+        registerEntity(51, "Skeleton");
+        registerEntity(52, "Spider");
+        registerEntity(53, "Giant");
+        registerEntity(54, "Zombie");
+        registerEntity(55, "Slime");
+        registerEntity(56, "Ghast");
+        registerEntity(57, "PigZombie");
+        registerEntity(58, "Enderman");
+        registerEntity(59, "CaveSpider");
+        registerEntity(60, "Silverfish");
+        registerEntity(61, "Blaze");
+        registerEntity(62, "LavaSlime");
+        registerEntity(63, "EnderDragon");
+        registerEntity(64, "WitherBoss");
+        registerEntity(65, "Bat");
+        registerEntity(66, "Witch");
+        registerEntity(67, "Endermite");
+        registerEntity(68, "Guardian");
+        registerEntity(90, "Pig");
+        registerEntity(91, "Sheep");
+        registerEntity(92, "Cow");
+        registerEntity(93, "Chicken");
+        registerEntity(94, "Squid");
+        registerEntity(95, "Wolf");
+        registerEntity(96, "MushroomCow");
+        registerEntity(97, "SnowMan");
+        registerEntity(98, "Ozelot");
+        registerEntity(99, "VillagerGolem");
+        registerEntity(100, "EntityHorse");
+        registerEntity(101, "Rabbit");
+        registerEntity(120, "Villager");
+        registerEntity(200, "EnderCrystal");
+
+        /* Potions */
+        registerPotion(0, "water");
+        registerPotion(64, "mundane");
+        registerPotion(32, "thick");
+        registerPotion(16, "awkward");
+
+        registerPotion(8198, "night_vision");
+        registerPotion(8262, "long_night_vision");
+
+        registerPotion(8206, "invisibility");
+        registerPotion(8270, "long_invisibility");
+
+        registerPotion(8203, "leaping");
+        registerPotion(8267, "long_leaping");
+        registerPotion(8235, "strong_leaping");
+
+        registerPotion(8195, "fire_resistance");
+        registerPotion(8259, "long_fire_resistance");
+
+        registerPotion(8194, "swiftness");
+        registerPotion(8258, "long_swiftness");
+        registerPotion(8226, "strong_swiftness");
+
+        registerPotion(8202, "slowness");
+        registerPotion(8266, "long_slowness");
+
+        registerPotion(8205, "water_breathing");
+        registerPotion(8269, "long_water_breathing");
+
+        registerPotion(8197, "healing");
+        registerPotion(8229, "strong_healing");
+
+        registerPotion(8204, "harming");
+        registerPotion(8236, "strong_harming");
+
+        registerPotion(8196, "poison");
+        registerPotion(8260, "long_poison");
+        registerPotion(8228, "strong_poison");
+
+        registerPotion(8193, "regeneration");
+        registerPotion(8257, "long_regeneration");
+        registerPotion(8225, "strong_regeneration");
+
+        registerPotion(8201, "strength");
+        registerPotion(8265, "long_strength");
+        registerPotion(8233, "strong_strength");
+
+        registerPotion(8200, "weakness");
+        registerPotion(8264, "long_weakness");
+
+    }
+
+    private static void registerEntity(Integer id, String name) {
+        ENTTIY_ID_TO_NAME.put(id, name);
+        ENTTIY_NAME_TO_ID.put(name, id);
+    }
+
+    private static void registerPotion(Integer id, String name) {
+        POTION_ID_TO_NAME.put(id, name);
+        POTION_NAME_TO_ID.put(name, id);
+    }
+}

src/main/java/us/myles/ViaVersion/transformers/IncomingTransformer.java

@@ -5,13 +5,14 @@ import org.bukkit.inventory.ItemStack;
 import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.ConnectionInfo;
 import us.myles.ViaVersion.ViaVersionPlugin;
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.packets.State;
 import us.myles.ViaVersion.util.PacketUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 
 public class IncomingTransformer {
     private final ConnectionInfo info;
@@ -82,7 +83,7 @@ public class IncomingTransformer {
             return;
         }
         if (packet == PacketType.PLAY_PLAYER_DIGGING) {
-            byte status = input.readByte();
+            int status = input.readByte() & 0xFF; // unsign
             if (status == 6) { // item swap
                 throw new CancelException();
             }
@@ -102,7 +103,9 @@ public class IncomingTransformer {
             if (slot == 45 && windowID == 0) {
                 try {
                     Class<?> setSlot = ReflectionUtil.nms("PacketPlayOutSetSlot");
-                    Object setSlotPacket = setSlot.getConstructors()[1].newInstance(windowID, slot, null);
+                    Constructor setSlotConstruct = setSlot.getDeclaredConstructor(int.class, int.class, ReflectionUtil.nms("ItemStack"));
+                    // properly construct
+                    Object setSlotPacket = setSlotConstruct.newInstance(windowID, slot, null);
                     info.getChannel().pipeline().writeAndFlush(setSlotPacket); // slot is empty
                     slot = -999; // we're evil, they'll throw item on the ground
                 } catch (ClassNotFoundException e) {
@@ -113,6 +116,8 @@ public class IncomingTransformer {
                     e.printStackTrace();
                 } catch (InvocationTargetException e) {
                     e.printStackTrace();
+                } catch (NoSuchMethodException e) {
+                    e.printStackTrace();
                 }
 
             }
@@ -121,7 +126,7 @@ public class IncomingTransformer {
             output.writeByte(button);
             output.writeShort(action);
             output.writeByte(mode);
-            output.writeBytes(input);
+            ItemSlotRewriter.rewrite1_9To1_8(input, output);
             return;
         }
         if (packet == PacketType.PLAY_CLIENT_SETTINGS) {
@@ -174,22 +179,14 @@ public class IncomingTransformer {
             int hand = PacketUtil.readVarInt(input);
 
             ItemStack inHand = ViaVersionPlugin.getHandItem(info);
-            Object item = null;
             try {
-                Method m = ReflectionUtil.obc("inventory.CraftItemStack").getDeclaredMethod("asNMSCopy", ItemStack.class);
-                item = m.invoke(null, inHand);
-            } catch (NoSuchMethodException e) {
-                e.printStackTrace();
-            } catch (ClassNotFoundException e) {
-                e.printStackTrace();
-            } catch (InvocationTargetException e) {
-                e.printStackTrace();
-            } catch (IllegalAccessException e) {
+                ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
+                ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
+                ItemSlotRewriter.writeItemStack(item, output);
+            } catch (Exception e) {
                 e.printStackTrace();
             }
 
-            PacketUtil.writeItem(item, output);
-
             short curX = input.readUnsignedByte();
             output.writeByte(curX);
             short curY = input.readUnsignedByte();
@@ -206,26 +203,25 @@ public class IncomingTransformer {
             output.writeByte(255);
             // write item in hand
             ItemStack inHand = ViaVersionPlugin.getHandItem(info);
-            Object item = null;
             try {
-                Method m = ReflectionUtil.obc("inventory.CraftItemStack").getDeclaredMethod("asNMSCopy", ItemStack.class);
-                item = m.invoke(null, inHand);
-            } catch (NoSuchMethodException e) {
-                e.printStackTrace();
-            } catch (ClassNotFoundException e) {
-                e.printStackTrace();
-            } catch (InvocationTargetException e) {
-                e.printStackTrace();
-            } catch (IllegalAccessException e) {
+                ItemSlotRewriter.ItemStack item = ItemSlotRewriter.ItemStack.fromBukkit(inHand);
+                ItemSlotRewriter.fixIdsFrom1_9To1_8(item);
+                ItemSlotRewriter.writeItemStack(item, output);
+            } catch (Exception e) {
                 e.printStackTrace();
             }
-            PacketUtil.writeItem(item, output);
 
             output.writeByte(-1);
             output.writeByte(-1);
             output.writeByte(-1);
             return;
         }
+        if (packet == PacketType.PLAY_CREATIVE_INVENTORY_ACTION) {
+            short slot = input.readShort();
+            output.writeShort(slot);
+
+            ItemSlotRewriter.rewrite1_9To1_8(input, output);
+        }
         output.writeBytes(input);
     }
 }

src/main/java/us/myles/ViaVersion/transformers/OutgoingTransformer.java

@@ -1,19 +1,17 @@
 package us.myles.ViaVersion.transformers;
 
-import com.google.gson.Gson;
-import com.google.gson.JsonObject;
-
 import io.netty.buffer.ByteBuf;
-
 import org.bukkit.entity.EntityType;
+import org.json.simple.JSONObject;
 import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
 import org.spacehq.mc.protocol.data.game.chunk.Column;
 import org.spacehq.mc.protocol.util.NetUtil;
-
 import us.myles.ViaVersion.CancelException;
 import us.myles.ViaVersion.ConnectionInfo;
 import us.myles.ViaVersion.ViaVersionPlugin;
 import us.myles.ViaVersion.api.ViaVersion;
+import us.myles.ViaVersion.slot.ItemSlotRewriter;
 import us.myles.ViaVersion.metadata.MetadataRewriter;
 import us.myles.ViaVersion.packets.PacketType;
 import us.myles.ViaVersion.packets.State;
@@ -28,7 +26,6 @@ import java.util.*;
 import static us.myles.ViaVersion.util.PacketUtil.*;
 
 public class OutgoingTransformer {
-    private static Gson gson = new Gson();
     private final ConnectionInfo info;
     private final ViaVersionPlugin plugin = (ViaVersionPlugin) ViaVersion.getInstance();
     private boolean cancel = false;
@@ -50,7 +47,7 @@ public class OutgoingTransformer {
         if (packet == null) {
             throw new RuntimeException("Outgoing Packet not found? " + packetID + " State: " + info.getState() + " Version: " + info.getProtocol());
         }
-//        if (packet != PacketType.PLAY_CHUNK_DATA && packet != PacketType.PLAY_KEEP_ALIVE && packet != PacketType.PLAY_TIME_UPDATE && (!packet.name().toLowerCase().contains("move") && !packet.name().contains("look")))
+//        if (packet != PacketType.PLAY_CHUNK_DATA && packet != PacketType.PLAY_KEEP_ALIVE && packet != PacketType.PLAY_TIME_UPDATE && (!packet.name().toLowerCase().contains("move") && !packet.name().toLowerCase().contains("look")))
 //            System.out.println("Packet Type: " + packet + " Original ID: " + packetID + " State:" + info.getState());
         if (packet.getPacketID() != -1) {
             packetID = packet.getNewPacketID();
@@ -60,15 +57,14 @@ public class OutgoingTransformer {
         PacketUtil.writeVarInt(packetID, output);
         if (packet == PacketType.PLAY_NAMED_SOUND_EFFECT) {
             String name = PacketUtil.readString(input);
+
             SoundEffect effect = SoundEffect.getByName(name);
             int catid = 0;
             String newname = name;
             if (effect != null) {
-            	if(effect.isBreakPlaceSound()) {
-            		input.readBytes(input.readableBytes());
-            		output.clear();
-            		return;
-            	}
+                if (effect.isBreakPlaceSound()) {
+                    throw new CancelException();
+                }
                 catid = effect.getCategory().getId();
                 newname = effect.getNewName();
             }
@@ -87,12 +83,12 @@ public class OutgoingTransformer {
                     if (!vehicleMap.containsKey(passenger))
                         throw new CancelException();
                     vehicle = vehicleMap.remove(passenger);
-                    writeVarInt(vehicle,output);
+                    writeVarInt(vehicle, output);
                     writeVarIntArray(Collections.<Integer>emptyList(), output);
-                } else{
+                } else {
                     writeVarInt(vehicle, output);
                     writeVarIntArray(Collections.singletonList(passenger), output);
-                    vehicleMap.put(passenger,vehicle);
+                    vehicleMap.put(passenger, vehicle);
                 }
                 return;
             }
@@ -115,6 +111,55 @@ public class OutgoingTransformer {
             output.writeBytes(input);
             return;
         }
+        if (packet == PacketType.PLAY_PLAYER_LIST_ITEM) {
+            int action = readVarInt(input);
+            writeVarInt(action, output);
+            int players = readVarInt(input);
+            writeVarInt(players, output);
+
+            // loop through players
+            for (int i = 0; i < players; i++) {
+                UUID uuid = readUUID(input);
+                writeUUID(uuid, output);
+                if (action == 0) { // add player
+                    writeString(readString(input), output); // name
+
+                    int properties = readVarInt(input);
+                    writeVarInt(properties, output);
+
+                    // loop through properties
+                    for (int j = 0; j < properties; j++) {
+                        writeString(readString(input), output); // name
+                        writeString(readString(input), output); // value
+                        boolean isSigned = input.readBoolean();
+                        output.writeBoolean(isSigned);
+                        if (isSigned) {
+                            writeString(readString(input), output); // signature
+                        }
+                    }
+
+                    writeVarInt(readVarInt(input), output); // gamemode
+                    writeVarInt(readVarInt(input), output); // ping
+                    boolean hasDisplayName = input.readBoolean();
+                    output.writeBoolean(hasDisplayName);
+                    if (hasDisplayName) {
+                        writeString(fixJson(readString(input)), output); // display name
+                    }
+                } else if ((action == 1) || (action == 2)) { // update gamemode || update latency
+                    writeVarInt(readVarInt(input), output);
+                } else if (action == 3) { // update display name
+                    boolean hasDisplayName = input.readBoolean();
+                    output.writeBoolean(hasDisplayName);
+                    if (hasDisplayName) {
+                        writeString(fixJson(readString(input)), output); // display name
+                    }
+                } else if (action == 4) { // remove player
+                    // no fields
+                }
+            }
+
+            return;
+        }
         if (packet == PacketType.PLAY_PLAYER_LIST_HEADER_FOOTER) {
             String header = readString(input);
             String footer = readString(input);
@@ -192,9 +237,14 @@ public class OutgoingTransformer {
 
         if (packet == PacketType.STATUS_RESPONSE) {
             String original = PacketUtil.readString(input);
-            JsonObject object = gson.fromJson(original, JsonObject.class);
-            object.get("version").getAsJsonObject().addProperty("protocol", info.getProtocol());
-            PacketUtil.writeString(gson.toJson(object), output);
+            try {
+                JSONObject json = (JSONObject) new JSONParser().parse(original);
+                JSONObject version = (JSONObject) json.get("version");
+                version.put("protocol", info.getProtocol());
+                PacketUtil.writeString(json.toJSONString(), output);
+            } catch (ParseException e) {
+                e.printStackTrace();
+            }
             return;
         }
         if (packet == PacketType.LOGIN_SUCCESS) {
@@ -221,7 +271,9 @@ public class OutgoingTransformer {
                 slot += 1; // add 1 so it's now 2-5
             }
             PacketUtil.writeVarInt(slot, output);
-            output.writeBytes(input);
+            
+            ItemSlotRewriter.rewrite1_8To1_9(input, output);
+            return;
         }
         if (packet == PacketType.PLAY_ENTITY_METADATA) {
             int id = PacketUtil.readVarInt(input);
@@ -338,6 +390,28 @@ public class OutgoingTransformer {
             output.writeBytes(input);
             return;
         }
+        if (packet == PacketType.PLAY_SET_SLOT) {
+            int windowId = input.readUnsignedByte();
+            output.writeByte(windowId);
+
+            short slot = input.readShort();
+            output.writeShort(slot);
+
+            ItemSlotRewriter.rewrite1_8To1_9(input, output);
+            return;
+        }
+        if (packet == PacketType.PLAY_WINDOW_ITEMS) {
+            int windowId = input.readUnsignedByte();
+            output.writeByte(windowId);
+
+            short count = input.readShort();
+            output.writeShort(count);
+
+            for (int i = 0; i < count; i++) {
+                ItemSlotRewriter.rewrite1_8To1_9(input, output);
+            }
+            return;
+        }
         if (packet == PacketType.PLAY_SPAWN_MOB) {
             int id = PacketUtil.readVarInt(input);
             PacketUtil.writeVarInt(id, output);
@@ -428,6 +502,20 @@ public class OutgoingTransformer {
             output.writeBytes(input);
             return;
         }
+        if (packet == PacketType.PLAY_ENTITY_EFFECT) {
+            int id = PacketUtil.readVarInt(input);
+            PacketUtil.writeVarInt(id, output);
+            byte effectID = input.readByte();
+            output.writeByte(effectID);
+            byte amplifier = input.readByte();
+            output.writeByte(amplifier);
+            int duration = PacketUtil.readVarInt(input);
+            PacketUtil.writeVarInt(duration, output);
+            // we need to write as a byte instead of boolean
+            boolean hideParticles = input.readBoolean();
+            output.writeByte(hideParticles ? 1 : 0);
+            return;
+        }
         if (packet == PacketType.PLAY_TEAM) {
             String teamName = PacketUtil.readString(input);
             PacketUtil.writeString(teamName, output);
@@ -497,7 +585,7 @@ public class OutgoingTransformer {
         output.writeBytes(input);
     }
 
-    private String fixJson(String line) {
+    public static String fixJson(String line) {
         if (line == null || line.equalsIgnoreCase("null")) {
             line = "{\"text\":\"\"}";
         } else {
@@ -507,11 +595,10 @@ public class OutgoingTransformer {
                 line = "{\"text\":" + line + "}";
         }
         try {
-        	new JSONParser().parse(line);
-        }
-        catch (org.json.simple.parser.ParseException e) {
-        	System.out.println("Invalid JSON String: \"" + line + "\" Please report this issue to the ViaVersion Github!");
-        	return "{\"text\":\"\"}";
+            new JSONParser().parse(line);
+        } catch (Exception e) {
+            System.out.println("Invalid JSON String: \"" + line + "\" Please report this issue to the ViaVersion Github: " + e.getMessage());
+            return "{\"text\":\"\"}";
         }
         return line;
     }

src/main/java/us/myles/ViaVersion/util/PacketUtil.java

@@ -3,6 +3,8 @@ package us.myles.ViaVersion.util;
 import com.google.common.base.Charsets;
 import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufInputStream;
+import io.netty.buffer.ByteBufOutputStream;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.MessageToByteEncoder;
@@ -11,6 +13,9 @@ import us.myles.ViaVersion.chunks.PacketChunk;
 import us.myles.ViaVersion.chunks.PacketChunkData;
 
 import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.nio.ByteBuffer;
@@ -21,6 +26,9 @@ import java.util.BitSet;
 import java.util.List;
 import java.util.UUID;
 
+import org.spacehq.opennbt.NBTIO;
+import org.spacehq.opennbt.tag.builtin.CompoundTag;
+
 public class PacketUtil {
     private static Method DECODE_METHOD;
     private static Method ENCODE_METHOD;
@@ -42,6 +50,25 @@ public class PacketUtil {
         }
     }
 
+    public static CompoundTag readNBT(ByteBuf input) throws IOException {
+        int readerIndex = input.readerIndex();
+        byte b = input.readByte();
+        if (b == 0) {
+            return null;
+        } else {
+            input.readerIndex(readerIndex);
+            return (CompoundTag) NBTIO.readTag(new DataInputStream(new ByteBufInputStream(input)));
+        }
+    }
+
+    public static void writeNBT(ByteBuf output, CompoundTag tag) throws IOException {
+        if (tag == null) {
+            output.writeByte(0);
+        } else {
+            NBTIO.writeTag(new DataOutputStream(new ByteBufOutputStream(output)), tag);
+        }
+    }
+
     public static List<Object> callDecode(ByteToMessageDecoder decoder, ChannelHandlerContext ctx, Object input) {
         List<Object> output = new ArrayList<Object>();
         try {
@@ -354,45 +381,6 @@ public class PacketUtil {
         return output;
     }
 
-    public static void writeItem(Object value, ByteBuf output) {
-        try {
-            Class<?> serializer = ReflectionUtil.nms("PacketDataSerializer");
-            Object init = serializer.getDeclaredConstructor(ByteBuf.class).newInstance(output);
-            Method toCall = init.getClass().getDeclaredMethod("a", ReflectionUtil.nms("ItemStack"));
-            toCall.invoke(init, value);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        } catch (InstantiationException e) {
-            e.printStackTrace();
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (InvocationTargetException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public static Object readItem(ByteBuf output) {
-        try {
-            Class<?> serializer = ReflectionUtil.nms("PacketDataSerializer");
-            Object init = serializer.getDeclaredConstructor(ByteBuf.class).newInstance(output);
-            Method toCall = init.getClass().getDeclaredMethod("i");
-            return toCall.invoke(init);
-        } catch (ClassNotFoundException e) {
-            e.printStackTrace();
-        } catch (NoSuchMethodException e) {
-            e.printStackTrace();
-        } catch (InstantiationException e) {
-            e.printStackTrace();
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (InvocationTargetException e) {
-            e.printStackTrace();
-        }
-		return null;
-    }
-
     public static long[] readBlockPosition(ByteBuf buf) {
         long val = buf.readLong();
         long x = (val >> 38); // signed
@@ -414,4 +402,12 @@ public class PacketUtil {
 
         return data;
     }
+
+    public static boolean containsCause(Throwable t, Class<? extends Throwable> c) {
+        while (t != null) {
+            t = t.getCause();
+            if (c.isAssignableFrom(t.getClass())) return true;
+        }
+        return false;
+    }
 }

src/main/java/us/myles/ViaVersion/util/ReflectionUtil.java

@@ -27,6 +27,18 @@ public class ReflectionUtil {
         return m.invoke(o);
     }
 
+    public static <T> T getStatic(Class<?> clazz, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = clazz.getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(null);
+    }
+
+    public static <T> T get(Object instance, Class<?> clazz, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
+        Field field = clazz.getDeclaredField(f);
+        field.setAccessible(true);
+        return (T) field.get(instance);
+    }
+
     public static <T> T get(Object o, String f, Class<T> t) throws NoSuchFieldException, IllegalAccessException {
         Field field = o.getClass().getDeclaredField(f);
         field.setAccessible(true);

src/main/resources/plugin.yml

@@ -1,6 +1,11 @@
 name: ViaVersion
 main: us.myles.ViaVersion.ViaVersionPlugin
 author: _MylesC
-version: 0.4.6
+version: ${version}
 load: startup
-loadbefore: [ProtocolLib, ProxyPipe]
+loadbefore: [ProtocolLib, ProxyPipe]
+commands:
+  viaversion:
+    description: Shows ViaVersion Version and more.
+    permission: viaversion.admin
+    aliases: [viaver]