Entity metadata memory leak test plugin

MetaTestPlugin.java

package com.forairan.metatest;

import java.lang.reflect.Field;
import java.util.Map;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.craftbukkit.v1_7_R3.CraftServer;
import org.bukkit.entity.EntityType;
import org.bukkit.entity.Horse;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.metadata.FixedMetadataValue;
import org.bukkit.metadata.MetadataStoreBase;
import org.bukkit.plugin.java.JavaPlugin;

public class MetaTestPlugin extends JavaPlugin implements Listener {

    @Override
    public void onEnable() {
        getServer().getPluginManager().registerEvents(this, this);
    }

    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (label.equalsIgnoreCase("metatest")) {
            if (sender instanceof Player) {
                Player p = (Player) sender;

                if (args.length < 1) {
                    sender.sendMessage("Usage: /metatest <number of entities>");
                    return false;
                } else {
                    int number = 10;
                    try {
                        number = Integer.parseInt(args[0]);
                    } catch (NumberFormatException nfe) {
                        sender.sendMessage("Invalid number; defaulting to 10.");
                    }

                    for (int i = 0; i < number; i++) {
                        final Horse horse = (Horse) p.getWorld().spawnEntity(p.getLocation(), EntityType.HORSE);
                        horse.setMetadata("bigData", new FixedMetadataValue(this, new ReallyBigObject()));
                        horse.remove();
                    }

                    sender.sendMessage("Spawned " + number + " horses, added metadata, and removed.");
                    sendMetadataStoreInfo(sender);
                    
                    return true;
                }
            } else {
                sender.sendMessage("Please execute this command ingame.");
                return false;
            }
        } else if (label.equalsIgnoreCase("gc")) {
            System.gc();
            sender.sendMessage("System.gc() executed.");
            
            return true;
        } else if (label.equalsIgnoreCase("checkmeta")) {
            sendMetadataStoreInfo(sender);
            
            return true;
        }

        return false;
    }

    private void sendMetadataStoreInfo(CommandSender sender) {
        // Get the entity map via reflection magic
        CraftServer craftServer = (CraftServer) getServer();
        Map metadataMap;

        try {
            Field f = MetadataStoreBase.class.getDeclaredField("metadataMap");
            f.setAccessible(true);
            metadataMap = (Map) f.get(craftServer.getEntityMetadata());
        } catch (ReflectiveOperationException ex) {
            sender.sendMessage("Error while reflecting: " + ex.getMessage());
            sender.sendMessage("See console for details.");
            ex.printStackTrace();
            return;
        }

        // Spit it out
        sender.sendMessage("Objects in entity metadata store: " + metadataMap.size());
    }

    private static class ReallyBigObject {

        private final byte[] data = new byte[16384];
    }
}

plugin.yml

name: EntityMetadataTest
version: 1
author: Forairan
main: com.forairan.metatest.MetaTestPlugin
commands:
    metatest:
        description: Tests the entity metadata store bug.
    gc:
        description: Runs System.gc().
    checkmeta:
        description: Checks the metadata store.