EventHandler.java

  @SubscribeEvent
	static void onWorldLoad(WorldEvent.Load e) {
		Random rand = new Random();
		WorldDataTable table = WorldDataTable.get(e.getWorld(), true);
		if(!table.didgen) {
			table.list.add(
					new OreData(
							rand.nextInt(256), 
							rand.nextInt(256), 
							rand.nextInt(256), 
							(((float) rand.nextInt(5000)) / 1000f), 
							rand.nextInt(20), 
							rand.nextInt(50), 
							rand.nextInt(5), 
							rand.nextInt(20), 
							rand.nextInt(100000)));
			table.didgen = true;
			table.markDirty();
		}
	}

OreData.java

package matyk.aqarium2.oreData;

import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class OreData {
	public int red, green, blue;
	public float hardness;
	public int damage, miningSpeed, miningLevel, armor, durability;
	
	public OreData() {
		
	}
	
	public OreData(int red, int green, int blue, float hardness, int damage, int miningSpeed, int miningLevel, int armor, int durability) {
		this.red = red;
		this.green = green;
		this.blue = blue;
		this.hardness = hardness;
		this.damage = damage;
		this.miningSpeed = miningSpeed;
		this.miningLevel = miningLevel;
		this.armor = armor;
		this.durability = durability;
	}
	
	@Override
	public String toString() {
		JSONObject obj = new JSONObject();
		JSONArray colors = new JSONArray();
		colors.add(red);
		colors.add(green);
		colors.add(blue);
		JSONArray stats = new JSONArray();
		stats.add(hardness);
		stats.add(damage);
		stats.add(miningSpeed);
		stats.add(miningLevel);
		stats.add(armor);
		stats.add(durability);
		obj.put("colors", colors);
		obj.put("stats", stats);
		return obj.toJSONString();
	}
	
	public OreData readFromJson(String json) {
		JSONParser parser = new JSONParser();
		JSONObject obj = null;
		try {
			obj = (JSONObject) parser.parse(json);
		} catch (ParseException e) {
			e.printStackTrace();
		}
		JSONArray colors = (JSONArray) obj.get("colors");
		JSONArray stats = (JSONArray) obj.get("stats");
		this.red = (int) colors.get(0);
		this.green = (int) colors.get(1);
		this.blue = (int) colors.get(2);
		this.hardness = (float) stats.get(0);
		this.damage = (int) stats.get(1);
		this.miningSpeed = (int) stats.get(2);
		this.miningLevel = (int) stats.get(3);
		this.armor = (int) stats.get(4);
		this.durability = (int) stats.get(5);
		return this;
	}
}

WorldDataTable.java

package matyk.aqarium2.worldData;

import java.util.ArrayList;

import matyk.aqarium2.main.Main;
import matyk.aqarium2.oreData.OreData;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.world.World;
import net.minecraft.world.storage.MapStorage;
import net.minecraft.world.storage.WorldSavedData;

public class WorldDataTable extends WorldSavedData {
	public boolean didgen;
	private static final String DATA_NAME = Main.MODID + "_TableData";
	public ArrayList<OreData> list = new ArrayList<OreData>();
	
	// Required constructors
	
	public WorldDataTable() {
		super(DATA_NAME);
	}
	public WorldDataTable(String s) {
		super(s);
	}
	
	@Override
	public void readFromNBT(NBTTagCompound cmpd) {
		didgen = cmpd.getBoolean("didGen");
		int size = cmpd.getInteger("dataSize");
		for(int i = 0; i < size; i++) {
			list.add(new OreData().readFromJson(cmpd.getString("data_" + i)));
		}
		markDirty();
	}
	
	@Override
	public NBTTagCompound writeToNBT(NBTTagCompound cmpd) {
		for(int i = 0; i < list.size(); i ++)
			cmpd.setString("data_" + i, list.get(i).toString());
		cmpd.setInteger("dataSize", list.size());
		cmpd.setBoolean("didGen", didgen);
		return cmpd;
	}

	public static WorldDataTable get(World world, boolean IS_GLOBAL) {
		MapStorage storage = IS_GLOBAL ? world.getMapStorage() : world.getPerWorldStorage();
		WorldDataTable instance = (WorldDataTable) storage.getOrLoadData(WorldDataTable.class, DATA_NAME);
		
		if (instance == null) {
			instance = new WorldDataTable();
			storage.setData(DATA_NAME, instance);
		}
		if(instance.didgen != true) {
			Random rand = new Random();
			instance.list.add(
					new OreData(
							rand.nextInt(256), 
							rand.nextInt(256), 
							rand.nextInt(256), 
							(((float) rand.nextInt(5000)) / 1000f), 
							rand.nextInt(20), 
							rand.nextInt(50), 
							rand.nextInt(5), 
							rand.nextInt(20), 
							rand.nextInt(100000)));
			instance.didgen = true;
			instance.markDirty();
		}
		return instance;
	}
}