Hello, I'm making a structure only generate 3 times within a world using a custom WorldSavedData class. Whenever I try accessing it, it gives me this crash:

---- Minecraft Crash Report ----
// You're mean.

Time: 10/11/14 1:05 AM
Description: Exception in server tick loop

java.lang.NullPointerException: Exception in server tick loop
at terrarium.data.WorldSavedDataT.getInt(WorldSavedDataT.java:50)
at terrarium.world.WorldGeneratorT.generateOverworld(WorldGeneratorT.java:26)
at terrarium.world.WorldGeneratorT.generate(WorldGeneratorT.java:17)
at cpw.mods.fml.common.registry.GameRegistry.generateWorld(GameRegistry.java:106)
at net.minecraft.world.gen.ChunkProviderServer.populate(ChunkProviderServer.java:314)
at net.minecraft.world.chunk.Chunk.populateChunk(Chunk.java:1157)
at net.minecraft.world.gen.ChunkProviderServer.originalLoadChunk(ChunkProviderServer.java:208)
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:149)
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:119)
at net.minecraft.server.MinecraftServer.initialWorldChunkLoad(MinecraftServer.java:305)
at net.minecraft.server.integrated.IntegratedServer.loadAllWorlds(IntegratedServer.java:79)
at net.minecraft.server.integrated.IntegratedServer.startServer(IntegratedServer.java:96)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:445)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:752)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_67, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 787348752 bytes (750 MB) / 1038876672 bytes (990 MB) up to 1038876672 bytes (990 MB)
JVM Flags: 3 total; -Xincgc -Xmx1024M -Xms1024M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 9, tallocated: 72
FML: MCP v9.05 FML v7.10.85.1224 Minecraft Forge 10.13.1.1224 4 mods loaded, 4 mods active
mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
FML{7.10.85.1224} [Forge Mod Loader] (forgeSrc-1.7.10-10.13.1.1224.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
Forge{10.13.1.1224} [Minecraft Forge] (forgeSrc-1.7.10-10.13.1.1224.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
terrarium{Indev} [Terrarium] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'

 

WorldData:

package terrarium.data;

import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.world.World;
import net.minecraft.world.WorldSavedData;
import net.minecraft.world.storage.MapStorage;

public class WorldSavedDataT extends WorldSavedData {
private static final String KEY = "TerrariumWorldSavedData";

private NBTTagCompound data;

public WorldSavedDataT(String name) {
	super(name);
}

public static WorldSavedDataT getWorldDataFor(World world) {
	MapStorage storage = world.perWorldStorage;
	WorldSavedDataT worldData = (WorldSavedDataT) storage.loadData(WorldSavedDataT.class, KEY);

	if(worldData == null) {
		worldData = new WorldSavedDataT(KEY);
		storage.setData(KEY, worldData);
	}

	return (WorldSavedDataT) storage.loadData(WorldSavedDataT.class, KEY);
}

@Override
public void readFromNBT(NBTTagCompound nbt) {
	if(!nbt.hasKey("Terrarium")) {
		nbt.setTag("Terrarium", new NBTTagCompound());
	}

	data = nbt.getCompoundTag("Terrarium");
}

@Override
public void writeToNBT(NBTTagCompound nbt) {
	nbt.setTag("Terrarium", data);
}

public void setInt(String name, int value) {
	data.setInteger(name, value);

	this.markDirty();
}

public int getInt(String name) {
	if(!data.hasKey(name)) {
		setInt(name, 0);
	}

	return data.getInteger(name);
}

public void setBoolean(String name, boolean value) {
	data.setBoolean(name, value);

	this.markDirty();
}

public boolean getBoolean(String name) {
	if(!data.hasKey(name)) {
		setBoolean(name, false);
	}

	return data.getBoolean(name);
}

public void setFloat(String name, float value) {
	data.setFloat(name, value);

	this.markDirty();
}

public float getFloat(String name) {
	if(!data.hasKey(name)) {
		setFloat(name, 0F);
	}

	return data.getFloat(name);
}

public void setDouble(String name, double value) {
	data.setDouble(name, value);

	this.markDirty();
}

public double getDouble(String name) {
	if(!data.hasKey(name)) {
		setDouble(name, 0D);
	}

	return data.getDouble(name);
}
}

 

WorldGenerator:

package terrarium.world;

import java.util.Random;

import net.minecraft.world.World;
import net.minecraft.world.chunk.IChunkProvider;
import terrarium.data.WorldSavedDataT;
import terrarium.util.MathUtil;
import terrarium.world.gen.WorldGenFloatingIsland;
import cpw.mods.fml.common.IWorldGenerator;

public class WorldGeneratorT implements IWorldGenerator {
@Override
public void generate(Random random, int chunkX, int chunkZ, World world, IChunkProvider chunkGenerator, IChunkProvider chunkProvider) {
	switch(world.provider.dimensionId) {
	case (0): {
		generateOverworld(random, chunkX * 16, chunkZ * 16, world);
		break;
	}
	}
}

public void generateOverworld(Random random, int x, int z, World world) {
	if(MathUtil.getChance(random, 1, 500)) {
		WorldSavedDataT worldData = WorldSavedDataT.getWorldDataFor(world);
		int amt = worldData.getInt("AmountOfStructures");

		if(amt < 4) {
			worldData.setInt("Structure", amt++);

			int x2 = x + random.nextInt(16);
			int z2 = z + random.nextInt(16);

			//Generate something
		}
	}

	if(MathUtil.getChance(random, 1, 150)) {
		WorldGenFloatingIsland.generate(world, random, x + random.nextInt(16), 200 + random.nextInt(32), z + random.nextInt(16));
	}
}
}

 

The crash occurs when I try generating a world.

Blehhhh, ok.

 

I plan on having LOTS of data being stored in the world NBT and didn't want to bother having multiple fields.