I'm trying to make a mod which adds custom armor and a GUI that can display certain properties of the armor, namely it's operation mode. These properties are stored as NBT tags, which I can set and acces, however I'm trying to write a function that checks the player's armor slots and detects if he's/she's wearing the custom armor and, if he/she is, get the NBT data from it.

Every attempt I've made at this so far only resulted in my game crashing or simply nothing happening. My code looked something like this

//Helmet
if (player.inventory.armorInventory[3] != null) {
   if (player.inventory.armorInventory[3].getItem() == MODNAME.Helmet) {
       return player.inventory.armorInventory[3].getCompoundTag().getInterger("mode");
   }
}

 

However, like I said this just crashes. Any help would be appreciated.

(Also, this code is being run in the onArmorTick method of the helmet, as it's supposed to serve as a sort of heads-up-display.)

 

EDIT: After doing some testing, it seems as though the crash is coming from trying to get the NBT data itself. The data is formatted as an interger with a value of 2.

I'm trying to make a mod which adds custom armor and a GUI that can display certain properties of the armor, namely it's operation mode. These properties are stored as NBT tags, which I can set and acces, however I'm trying to write a function that checks the player's armor slots and detects if he's/she's wearing the custom armor and, if he/she is, get the NBT data from it.

Every attempt I've made at this so far only resulted in my game crashing or simply nothing happening. My code looked something like this

//Helmet
if (player.inventory.armorInventory[3] != null) {
   if (player.inventory.armorInventory[3].getItem() == MODNAME.Helmet) {
       return player.inventory.armorInventory[3].getCompoundTag().getInterger("mode");
   }
}

 

However, like I said this just crashes. Any help would be appreciated.

(Also, this code is being run in the onArmorTick method of the helmet, as it's supposed to serve as a sort of heads-up-display.)

Give the crash.

Here's the crash report

 

---- Minecraft Crash Report ----

// My bad.

 

Time: 2/21/15 7:20 PM

Description: Ticking player

 

java.lang.NullPointerException: Ticking player

at com.sciman.cyborg.items.ItemCyborgHelmet.grabArmorModes(ItemCyborgHelmet.java:49)

at com.sciman.cyborg.items.ItemCyborgHelmet.onArmorTick(ItemCyborgHelmet.java:38)

at net.minecraft.entity.player.InventoryPlayer.decrementAnimations(InventoryPlayer.java:355)

at net.minecraft.entity.player.EntityPlayer.onLivingUpdate(EntityPlayer.java:610)

at net.minecraft.entity.EntityLivingBase.onUpdate(EntityLivingBase.java:1816)

at net.minecraft.entity.player.EntityPlayer.onUpdate(EntityPlayer.java:327)

at net.minecraft.entity.player.EntityPlayerMP.onUpdateEntity(EntityPlayerMP.java:330)

at net.minecraft.network.NetHandlerPlayServer.processPlayer(NetHandlerPlayServer.java:329)

at net.minecraft.network.play.client.C03PacketPlayer.processPacket(C03PacketPlayer.java:37)

at net.minecraft.network.play.client.C03PacketPlayer.processPacket(C03PacketPlayer.java:111)

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:241)

at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:182)

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:726)

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:614)

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:118)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:485)

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:

---------------------------------------------------------------------------------------

 

-- Head --

Stacktrace:

at com.sciman.cyborg.items.ItemCyborgHelmet.grabArmorModes(ItemCyborgHelmet.java:49)

at com.sciman.cyborg.items.ItemCyborgHelmet.onArmorTick(ItemCyborgHelmet.java:38)

at net.minecraft.entity.player.InventoryPlayer.decrementAnimations(InventoryPlayer.java:355)

at net.minecraft.entity.player.EntityPlayer.onLivingUpdate(EntityPlayer.java:610)

at net.minecraft.entity.EntityLivingBase.onUpdate(EntityLivingBase.java:1816)

at net.minecraft.entity.player.EntityPlayer.onUpdate(EntityPlayer.java:327)

 

-- Player being ticked --

Details:

Entity Type: null (net.minecraft.entity.player.EntityPlayerMP)

Entity ID: 0

Entity Name: Player206

Entity's Exact location: 1323.34, 56.00, 186.43

Entity's Block location: World: (1323,56,186), Chunk: (at 11,3,10 in 82,11; contains blocks 1312,0,176 to 1327,255,191), Region: (2,0; contains chunks 64,0 to 95,31, blocks 1024,0,0 to 1535,255,511)

Entity's Momentum: 0.00, -0.08, 0.00

Stacktrace:

at net.minecraft.entity.player.EntityPlayerMP.onUpdateEntity(EntityPlayerMP.java:330)

at net.minecraft.network.NetHandlerPlayServer.processPlayer(NetHandlerPlayServer.java:329)

at net.minecraft.network.play.client.C03PacketPlayer.processPacket(C03PacketPlayer.java:37)

at net.minecraft.network.play.client.C03PacketPlayer.processPacket(C03PacketPlayer.java:111)

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:241)

 

-- Ticking connection --

Details:

Connection: net.minecraft.network.NetworkManager@794dfd82

Stacktrace:

at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:182)

at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:726)

at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:614)

at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:118)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:485)

at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:752)

 

-- System Details --

Details:

Minecraft Version: 1.7.10

Operating System: Windows 7 (amd64) version 6.1

Java Version: 1.7.0_75, Oracle Corporation

Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation

Memory: 881999816 bytes (841 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: 0, tallocated: 0

FML: MCP v9.05 FML v7.10.85.1291 Minecraft Forge 10.13.2.1291 4 mods loaded, 4 mods active

mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

FML{7.10.85.1291} [Forge Mod Loader] (forgeSrc-1.7.10-10.13.2.1291.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

Forge{10.13.2.1291} [Minecraft Forge] (forgeSrc-1.7.10-10.13.2.1291.jar) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

cyborgmod{1.0} [cyborgmod] (bin) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available

Profiler Position: N/A (disabled)

Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used

Player Count: 1 / 8; [EntityPlayerMP['Player206'/0, l='Mod Testing', x=1323.34, y=56.00, z=186.43]]

Type: Integrated Server (map_client.txt)

Is Modded: Definitely; Client brand changed to 'fml,forge'

Put a != null check on the getTagCompound as well. I've learned the hard way if you try to get a value from a null tag compound you're gonna have a bad time.

Ok, so I tried that with this code

 

public int[] grabArmorModes(EntityPlayer player) {
	int[] ret_mod = new int[] {0,0,0,0};
	if (player.inventory.armorInventory[3] != null) {
		if (player.inventory.armorInventory[3].getItem() == CyborgMod.cyborgHelmet) {
			System.out.println(player.inventory.armorInventory[3].getItem().getUnlocalizedName());
			NBTTagCompound temp = player.inventory.armorInventory[3].getTagCompound();
			if (temp != null) {
				ret_mod[0] = temp.getInteger("mode");
				System.out.println("Sucess! got int" + String.valueOf(temp.getInteger("mode")));
			}
		}
	}
	return ret_mod;

}

(grabArmorModes is the function used by the helmet object to pass the armor values to the GUI to display)

 

It prints the item's name to the console, but never gets to the next print value, so the NBT tag must be return null.

This is where I declare the NBT data

//Declare NBT data
	NBTTagCompound tag = new NBTTagCompound();
	tag.setInteger("mode", 2);
	tag.setFloat("power",0F);

 

What am I doing wrong?

EDIT: I'm going to try changing it so that the GUI itself gets the armor values, not the helmet.

EDIT AGAIN: It looks like the NBT data always returns null. I'm goign to try and see if I can fix that.

My guess you are declaring it wrong.

//Declare NBT data
	NBTTagCompound tag = new NBTTagCompound();
	tag.setInteger("mode", 2);
	tag.setFloat("power",0F);

 

What is this doing? You simply make new NBT object, that's all.

 

write wraped getter for NBTTag:

if (stack.getTagCompound() == null) stack.tagCompound = new NBTTagCompound()
return stack.getTagCompound() ;

in what method would I put the getter, since it would go into an armor item?

 

Edit: Actually, maybe I should just change this thread to 'How do I add NBT data to an item on creation and retrieve that data from a GUI?'

I'll just write it: post whole code of your armour.

 

Creating new local (in-method) NBT and putting values into it doesn't magically make that NBTTag be itemstack's one. You need to itemstack.nbttag = new NBT whenever it is null;

Nevermind, i figured it out.

 

I put this code into the armor

if (stack.stackTagCompound == null) {
		stack.stackTagCompound = new NBTTagCompound();
		stack.stackTagCompound.setInteger("mode", 2);
		stack.stackTagCompound.setFloat("power", 0F);
		System.out.println("Made NBT data");
	}