Salvando ItemStacks completos como se fossem Strings: MC 1.6.4

ItemStackIOUtil.java

package com.arzio.exemplo;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.lang.reflect.Method;

import org.apache.commons.lang.Validate;
import org.bukkit.craftbukkit.v1_6_R3.inventory.CraftItemStack;

import net.minecraft.server.v1_6_R3.NBTCompressedStreamTools;
import net.minecraft.server.v1_6_R3.NBTTagCompound;

/**
 * EN: This example is ready for copy-and-paste.
 * PT-BR: Este exemplo esta pronto para ser copiado e colado.
 */
public class ItemStackIOUtil {

    private static Class<?> baseEncoder;
    private static Method encodeMethod;
    private static Method decodeMethod;
    private static Object base64;

    static {
        try {
            // EN: We need to get the BaseEncoding class through reflection since Cauldron
            // has a bug when using directly the class.

            // PT-BR: Precisamos obter a classe BaseEncoding atraves de reflection porque
            // o Cauldron tem um bug quando usa diretamente a classe.

            baseEncoder = Class.forName("com.google.common.io.BaseEncoding");
            base64 = baseEncoder.getDeclaredMethod("base64").invoke(null);
            encodeMethod = baseEncoder.getDeclaredMethod("encode", new Class[] { byte[].class });
            decodeMethod = baseEncoder.getDeclaredMethod("decode", new Class[] { CharSequence.class });
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * EN: Transforms an ItemStack into a String that can be saved anywhere. PT-BR:
     * Transforma um ItemStack em uma String que pode ser salva em qualquer lugar.
     * 
     * @return Base64 {@link String}.
     */
    public static String getStackAsString(org.bukkit.inventory.ItemStack itemStack) {
        // EN: Throws NullPointerException with a error message if the stack is null
        // PT-BR: Arremessa um NullPointerException com uma mensagem de erro se o stack for
        // null
        Validate.notNull(itemStack, "The ItemStack must not be null!");

        // EN: Creates an empty NBT Compound to be filled with our stack
        // PT-BR: Cria um NBT Compound vazio para ser preenchido com nosso stack
        NBTTagCompound nbtTagCompound = new NBTTagCompound();

        // EN: Creates a NMS ItemStack copy of a Bukkit ItemStack
        // PT-BR: Cria uma copia de ItemStack NMS a partir do ItemStack do Bukkit
        net.minecraft.server.v1_6_R3.ItemStack nmsItemStack = CraftItemStack.asNMSCopy(itemStack);

        // EN: Saves the NMS ItemStack into the empty Compound
        // PT-BR: Salva o ItemStack NMS no Compound vazio
        nmsItemStack.save(nbtTagCompound);

        try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
            // EN: Saves the NBT Compound into our OutputStream
            // PT-BR: Salva o NBT Compound em nosso OutputStream
            NBTCompressedStreamTools.a(nbtTagCompound, outputStream);

            // EN: Returns a Base64 String of the resulting byte array
            // PT-BR: Retorna uma String Base64 to array de bytes resultante
            return encode(outputStream.toByteArray());
        } catch (Exception e) {
            throw new RuntimeException("Failed to save the ItemStack in a String!", e);
        }
    }

    /**
     * EN: Creates a ItemStack from a Base64 String. PT-BR: Cria um ItemStack a
     * partir de uma String Base64.
     * 
     * @return Bukkit {@link org.bukkit.inventory.ItemStack}.
     */
    public static org.bukkit.inventory.ItemStack createStackFromString(String itemStackString) {
        // EN: Throws NullPointerException with a error message if the String is null
        // PT-BR: Faz throw em NullPointerException com uma mensagem de erro se a String for
        // null
        Validate.notNull(itemStackString, "The String must not be null!");

        // EN: Decodes the String Base64, transforming it into a byte array
        // PT-BR: Decodifica a String Base64, transformando-a em um array de bytes
        byte[] decodedStack = decode(itemStackString);

        try (ByteArrayInputStream inputStream = new ByteArrayInputStream(decodedStack)) {

            // EN: Gets a NBT Compound from the byte array
            // PT-BR: Obtem um NBT Compound a partir do array de bytes
            NBTTagCompound nbtTagCompound = NBTCompressedStreamTools.a(inputStream);

            // EN: Creates a new NMS ItemStack from the Compound
            // PT-BR: Cria um novo ItemStack NMS a partir do Compound
            net.minecraft.server.v1_6_R3.ItemStack craftItemStack = net.minecraft.server.v1_6_R3.ItemStack
                    .createStack(nbtTagCompound);

            // EN: Returns a Bukkit-copy of the NMS ItemStack.
            // PT-BR: Retorna um ItemStack Bukkit copiado do ItemStack NMS.
            return CraftItemStack.asBukkitCopy(craftItemStack);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    private static String encode(byte[] dataArray) {
        try {
            return (String) encodeMethod.invoke(base64, new Object[] { dataArray });
        } catch (Exception e) {
            throw new RuntimeException("Something went wrong while encoding the String", e);
        }
    }

    private static byte[] decode(String base64String) {
        try {
            return (byte[]) decodeMethod.invoke(base64, new Object[] { base64String });
        } catch (Exception e) {
            throw new RuntimeException("Something went wrong while decoding the String", e);
        }
    }

}