I want to add my two custom items to chests that generate along with the world. I want it so that between 1-25 coins in a stack have a chance of appearing, seems simple enough right? But after looking through various GitHub entries and how-to, I just can't get my head around the Forge Loot System. I added two item entries to test out the system but I get a nullpointer exception. Any suggestions as to how I go about this?

 

Here's my code. Also lootLoad doesn't need @SubscribeEvent because that was already done in my EventHandlerClass.

 

package com.TonyTiger.simplecoins.world;

import com.TonyTiger.simplecoins.Main;
import com.TonyTiger.simplecoins.items.ModItems;

import net.minecraft.util.ResourceLocation;
import net.minecraft.world.storage.loot.LootContext;
import net.minecraft.world.storage.loot.LootEntry;
import net.minecraft.world.storage.loot.LootEntryItem;
import net.minecraft.world.storage.loot.LootEntryTable;
import net.minecraft.world.storage.loot.LootPool;
import net.minecraft.world.storage.loot.LootTableList;
import net.minecraft.world.storage.loot.conditions.LootCondition;
import net.minecraft.world.storage.loot.functions.LootFunction;
import net.minecraftforge.event.LootTableLoadEvent;

public class genCoinsInWorld {
//10% chance for gold coins to spawn, 5% chance for iron coins to spawn
public static int goldChance = 10, ironChance = 5;
public static int minGoldGen = 0, maxGoldGen = 25, 
				  minIronGen = 0, maxIronGen = 25;
public static final ResourceLocation SIMPLECOINS_LOOT_TABLE =
		LootTableList.register(new ResourceLocation(Main.MODID,
											"simplecoins_loot_table"));

public static void lootLoad(LootTableLoadEvent event){
	if(!event.getName().getResourceDomain().equals("Minecraft")
	&& !event.getName().getResourcePath().contains("/") &&
		!event.getName().getResourcePath().contains("CHEST"))
		return;
//		LootEntry LE = new LootEntryTable(SIMPLECOINS_LOOT_TABLE, 25, 0, 
//				new LootCondition[0], "simplecoins:loot_table");
	LootEntry iron = new LootEntryItem(ModItems.IRONCOIN, goldChance, 0, new LootFunction[0], new LootCondition[0], "simplecoins:loot_ironcoin");
	LootEntry gold = new LootEntryItem(ModItems.IRONCOIN, ironChance, 0, new LootFunction[0], new LootCondition[0], "simplecoins:loot_goldcoin");
	LootPool main = event.getTable().getPool("main");
	main.addEntry(gold);
	main.addEntry(iron);
}
}

 

And the error message when I try to generate a world.

 

---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 1/14/17 5:19 PM
Description: Exception in server tick loop

com.google.common.util.concurrent.UncheckedExecutionException: java.lang.NullPointerException
at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2201)
at com.google.common.cache.LocalCache.get(LocalCache.java:3934)
at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3938)
at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4821)
at com.google.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4827)
at net.minecraft.world.storage.loot.LootTableManager.getLootTableFromLocation(LootTableManager.java:39)
at net.minecraft.world.storage.loot.LootTableManager.reloadLootTables(LootTableManager.java:48)
at net.minecraft.world.storage.loot.LootTableManager.<init>(LootTableManager.java:34)
at net.minecraft.world.WorldServer.init(WorldServer.java:156)
at net.minecraft.server.integrated.IntegratedServer.loadAllWorlds(IntegratedServer.java:87)
at net.minecraft.server.integrated.IntegratedServer.init(IntegratedServer.java:124)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:507)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at com.TonyTiger.simplecoins.world.genCoinsInWorld.lootLoad(genCoinsInWorld.java:36)
at com.TonyTiger.simplecoins.event.EventHandlerCommon.lootLoad(EventHandlerCommon.java:63)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_6_EventHandlerCommon_lootLoad_LootTableLoadEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:185)
at net.minecraftforge.event.ForgeEventFactory.loadLootTable(ForgeEventFactory.java:628)
at net.minecraftforge.common.ForgeHooks.loadLootTable(ForgeHooks.java:1103)
at net.minecraft.world.storage.loot.LootTableManager$Loader.loadBuiltinLootTable(LootTableManager.java:148)
at net.minecraft.world.storage.loot.LootTableManager$Loader.load(LootTableManager.java:71)
at net.minecraft.world.storage.loot.LootTableManager$Loader.load(LootTableManager.java:52)
at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3524)
at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2317)
at com.google.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2280)
at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2195)
... 12 more


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

-- System Details --
Details:
Minecraft Version: 1.11.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_111, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 232640400 bytes (221 MB) / 542638080 bytes (517 MB) up to 928514048 bytes (885 MB)
JVM Flags: 0 total; 
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML: MCP 9.38 Powered by Forge 13.20.0.2206 6 mods loaded, 6 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJAA	minecraft{1.11.2} [Minecraft] (minecraft.jar) 
UCHIJAA	mcp{9.19} [Minecraft Coder Pack] (minecraft.jar) 
UCHIJAA	FML{8.0.99.99} [Forge Mod Loader] (forgeSrc-1.11.2-13.20.0.2206.jar) 
UCHIJAA	forge{13.20.0.2206} [Minecraft Forge] (forgeSrc-1.11.2-13.20.0.2206.jar) 
UCHIJAA	simplecoins{0.6.0} [simple Coins] (bin) 
UCHIJAA	examplemod{1.0} [Example Mod] (bin) 
Loaded coremods (and transformers): 
GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
Profiler Position: N/A (disabled)
Player Count: 0 / 8; []
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'

Caused by: java.lang.NullPointerException

at com.TonyTiger.simplecoins.world.genCoinsInWorld.lootLoad(genCoinsInWorld.java:36)

 

Looks like this line isn't working:

LootPool main = event.getTable().getPool("main");

Was writing the same thing as Draco.

Also, please name your packages in lowercase and start your class name with an uppercase. It's a java standard ^^

Well, this is embarrassing. Thanks though, works now, just gotta set the possible stack sizes.

 

public static void lootLoad(LootTableLoadEvent event){
	if(!event.getName().getResourcePath().contains("chest"))
		return;
	LootEntry iron = new LootEntryItem(ModItems.IRONCOIN, 100, 0, new LootFunction[0], new LootCondition[0], "simplecoins:loot_ironcoin");
	LootEntry gold = new LootEntryItem(ModItems.GOLDCOIN, 100, 0, new LootFunction[0], new LootCondition[0], "simplecoins:loot_goldcoin");
	LootPool main = event.getTable().getPool("main");
	main.addEntry(gold);
	main.addEntry(iron);

}

By the way, feel free to take a look at my LootUtils class and a very basic usage of same.

 

(d7: any suggestions on how I'd make the giant list of ints more legible without having to check all the paramter names?  Using variables would work, but would take up a bunch of lines...)

By the way, feel free to take a look at my LootUtils class and a very basic usage of same.

 

Thanks man! This should help me in figuring out what I should do!

(d7: any suggestions on how I'd make the giant list of ints more legible without having to check all the paramter names?  Using variables would work, but would take up a bunch of lines...)

 

The latest version of IDEA will automatically show the name of any parameter you pass a literal value to, which would help with those methods.

 

The latest version of IDEA will automatically show the name of any parameter you pass a literal value to, which would help with those methods.

 

Oh that's nice.  Shame I use Eclipse.

 

Then again, I've been off in Unity3D land and you know what I miss?

Refactor tools that do things other than "rename." Or the ability to define a super class and interfaces when creating a new class (Microsoft actually REMOVED this feature between 2005 and 2015....)

 

or a builder:

 

new LootBuilder()
    .item(<item>)
    .metaRange(<min>, <max>)
    .weight(<weight>)
    // and so on
    .addTo(<loot table>);

 

Damn, should have thought of that.  And I don't feel like refactoring it now...

Refactor tools that do things other than "rename."

You think that is a lot? Check this out (and I don't think that's even everything)

 

No, I'm complaining that that's all Visual Studio has, and not more.

 

I'm grouching that the things I want aren't there.  I've used Extract Interface a dozen times, extract superclass at least twice.  No push up/pull down, but I can see its use.  Used Encapsulate fields a few times (usually through the auto-hinter).  Use Interface Where Possible I've done when using Extract Interface/Superclass...

 

I freaking love those options and I wish Visual Studio had them.