Add Util to get ItemStacks in Json Format for hover components

item-nbt-api/src/main/java/de/tr7zw/changeme/nbtapi/utils/NBTJsonUtil.java

@@ -0,0 +1,41 @@
+package de.tr7zw.changeme.nbtapi.utils;
+
+import java.util.Optional;
+
+import org.bukkit.inventory.ItemStack;
+
+import com.google.gson.JsonElement;
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.DataResult;
+import com.mojang.serialization.JsonOps;
+
+import de.tr7zw.changeme.nbtapi.NbtApiException;
+import de.tr7zw.changeme.nbtapi.utils.nmsmappings.ClassWrapper;
+import de.tr7zw.changeme.nbtapi.utils.nmsmappings.MojangToMapping;
+import de.tr7zw.changeme.nbtapi.utils.nmsmappings.ReflectionMethod;
+
+public class NBTJsonUtil {
+
+    /**
+     * 1.20.3+ only. Used to convert items into Json, used in Chat Hover Components.
+     * 
+     * @param itemStack
+     * @return
+     * @throws NbtApiException
+     */
+    @SuppressWarnings("unchecked")
+    public static JsonElement itemStackToJson(ItemStack itemStack) throws NbtApiException {
+        try {
+            Codec<Object> itemStackCodec = (Codec<Object>) ClassWrapper.NMS_ITEMSTACK.getClazz()
+                    .getField(MojangToMapping.getMapping().get("net.minecraft.world.item.ItemStack#CODEC")).get(null);
+            Object stack = ReflectionMethod.ITEMSTACK_NMSCOPY.run(null, itemStack);
+            DataResult<JsonElement> result = itemStackCodec.encode(stack, JsonOps.INSTANCE,
+                    JsonOps.INSTANCE.emptyMap());
+            Optional<JsonElement> opt = (Optional<JsonElement>) result.getClass().getMethod("result").invoke(result);
+            return opt.orElse(null);
+        } catch (Exception ex) {
+            throw new NbtApiException("Error trying to get Json of an ItemStack.", ex);
+        }
+    }
+
+}

item-nbt-api/src/main/java/de/tr7zw/changeme/nbtapi/utils/nmsmappings/MojangToMapping.java

@@ -145,6 +145,7 @@ public class MojangToMapping {
             put("net.minecraft.world.entity.Entity#getEncodeId()", "bw");
             put("net.minecraft.world.level.block.entity.BlockEntity#saveWithId()", "p");
             put("net.minecraft.world.level.block.entity.BlockEntity#getBlockState()", "r");
+            put("net.minecraft.world.item.ItemStack#CODEC", "a");
         }
 
     };
@@ -169,6 +170,7 @@ public class MojangToMapping {
             put("net.minecraft.util.datafix.DataFixers#getDataFixer()", "a");
             put("net.minecraft.util.datafix.fixes.References#ITEM_STACK", "t");
             put("net.minecraft.nbt.NbtOps#INSTANCE", "a");
+            put("net.minecraft.world.item.ItemStack#CODEC", "b");
         }
 
     };
@@ -193,6 +195,7 @@ public class MojangToMapping {
             put("net.minecraft.server.MinecraftServer#registryAccess()", "ba");
             put("net.minecraft.world.entity.Entity#getEncodeId()", "bK");
             put("net.minecraft.world.level.block.entity.BlockEntity#getBlockState()", "m");
+            put("net.minecraft.world.item.ItemStack#CODEC", "a");
         }
 
     };

item-nbt-plugin/src/main/java/de/tr7zw/nbtapi/plugin/NBTAPI.java

@@ -41,6 +41,7 @@ import de.tr7zw.nbtapi.plugin.tests.items.DirectApplyMetaTest;
 import de.tr7zw.nbtapi.plugin.tests.items.DirectApplyTest;
 import de.tr7zw.nbtapi.plugin.tests.items.EmptyItemTest;
 import de.tr7zw.nbtapi.plugin.tests.items.ItemConversionTest;
+import de.tr7zw.nbtapi.plugin.tests.items.ItemJsonTest;
 import de.tr7zw.nbtapi.plugin.tests.items.ItemMergingTest;
 import de.tr7zw.nbtapi.plugin.tests.items.ItemStackConversionTest;
 import de.tr7zw.nbtapi.plugin.tests.items.LegacyItemTest;
@@ -111,6 +112,7 @@ public class NBTAPI extends JavaPlugin {
         }
         if (MinecraftVersion.isAtLeastVersion(MinecraftVersion.MC1_20_R4)) {
             apiTests.add(new LegacyItemTest());
+            apiTests.add(new ItemJsonTest());
         }
         apiTests.add(new ComponentsTest());
         apiTests.add(new EmptyItemTest());

item-nbt-plugin/src/main/java/de/tr7zw/nbtapi/plugin/tests/items/ItemJsonTest.java

@@ -0,0 +1,30 @@
+package de.tr7zw.nbtapi.plugin.tests.items;
+
+import org.bukkit.Material;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.meta.ItemMeta;
+
+import com.google.gson.JsonElement;
+
+import de.tr7zw.changeme.nbtapi.NBT;
+import de.tr7zw.changeme.nbtapi.NBTItem;
+import de.tr7zw.changeme.nbtapi.NbtApiException;
+import de.tr7zw.changeme.nbtapi.utils.NBTJsonUtil;
+import de.tr7zw.nbtapi.plugin.tests.Test;
+
+public class ItemJsonTest implements Test {
+
+    @Override
+    public void test() throws Exception {
+        ItemStack item = new ItemStack(Material.STONE);
+        ItemMeta meta = item.getItemMeta();
+        meta.setDisplayName("test");
+        meta.setUnbreakable(true);
+        item.setItemMeta(meta);
+        JsonElement elem = NBTJsonUtil.itemStackToJson(item);
+        if (elem == null) {
+            throw new NbtApiException("Getting the Json didn't work correctly! " + item);
+        }
+    }
+
+}