Ok so i have a Tile Entity and block to go with it. I want one of my entities to set that block, then modify something in it's tile Entity. It keeps coming up with a NullPointerException.

 

Code:

 

Block:

 

package com.apmods.magicraft.block;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.world.World;

public class BlockPortkey extends BlockBase{

public BlockPortkey(String name) {
	super(name);
	// TODO Auto-generated constructor stub
}

public boolean hasTileEntity(int metadata)
{
    return true;
}

public TileEntity createNewTileEntity(World par1World)
{
    try
    {
        return new TileEntityPortkey();
    }
    catch (Exception var3)
    {
        throw new RuntimeException(var3);
    }
}
public void setPortkeyCoords(EntityPlayer player, World world, int x, int y, int z, int x1, int y1, int z1){
	if(!world.isRemote){
		TileEntityPortkey p = (TileEntityPortkey)world.getTileEntity(x, y, z);
		p.setPortkeyCoords(world, x1, y1, z1);
	}
}
public boolean onBlockActivated(World world, int par2, int par3, int par4, EntityPlayer par5EntityPlayer, int par6, float par7, float par8, float par9)
    {
                if(!world.isRemote)
                {
                        TileEntityPortkey t = (TileEntityPortkey) world.getTileEntity(par2, par3, par4);
                        t.teleport(world, par5EntityPlayer);
                }
                return true;
    }

}

 

 

Relevant Entity code:

 

Block block = this.worldObj.getBlock(mop.blockX, mop.blockY, mop.blockZ);
   Material mat = this.worldObj.getBlock(mop.blockX, mop.blockY, mop.blockZ).getMaterial();
   BlockPortkey portkey = (BlockPortkey) BlockManager.portkey;
   portkey.createNewTileEntity(worldObj);
   this.worldObj.setBlock(mop.blockX, mop.blockY, mop.blockZ, portkey);
   System.out.println("setBlock");
   TileEntityPortkey p = (TileEntityPortkey) portkey.createNewTileEntity(worldObj);
   p.setPortkeyCoords(worldObj, this.getCoord(1), this.getCoord(2), this.getCoord(3));
   this.setDead();

 

 

TileEntity:

 

package com.apmods.magicraft.block;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.world.World;

public class TileEntityPortkey extends TileEntity{
int prevx = 0;
int prevy = 0;
int prevz = 0;
 int x = 0;
 int y = 0;
 int z = 0;
@Override
public void readFromNBT(NBTTagCompound nbt)
{
    super.readFromNBT(nbt);
    this.x = nbt.getInteger("xcoord");
    this.y = nbt.getInteger("ycoord");
    this.z = nbt.getInteger("zcoord");
    this.prevx = nbt.getInteger("prevxcoord");
    this.prevy = nbt.getInteger("prevycoord");
    this.prevz = nbt.getInteger("prevzcoord");
}
@Override
public void writeToNBT(NBTTagCompound nbt)
{
    super.writeToNBT(nbt);
    nbt.setInteger("xcoord", x);
    nbt.setInteger("ycoord", y);
    nbt.setInteger("xcoord", z);
    nbt.setInteger("prevxcoord", prevx);
    nbt.setInteger("prevycoord", prevy);
    nbt.setInteger("prevzcoord", prevz);
}
public void setPortkeyCoords(World world, int x1, int y1, int z1) {
	x = x1;
	y = y1;
	z = z1;
	world.notifyBlockChange(x, y, z, BlockManager.portkey);

}
public void teleport(World world, EntityPlayer par5EntityPlayer) {
	if(world.isAirBlock(x, y, z)){
		prevx = (int) par5EntityPlayer.posX;
		prevy = (int) par5EntityPlayer.posY;
		prevz = (int) par5EntityPlayer.posZ;
		par5EntityPlayer.setPositionAndUpdate(x, y, z);
	}

}


}

 

 

Crash Report:

 

Caused by: java.lang.NullPointerException
at com.apmods.magicraft.block.BlockPortkey.onBlockActivated(BlockPortkey.java:41) ~[blockPortkey.class:?]
at net.minecraft.server.management.ItemInWorldManager.activateBlockOrUseItem(ItemInWorldManager.java:409) ~[itemInWorldManager.class:?]
at net.minecraft.network.NetHandlerPlayServer.processPlayerBlockPlacement(NetHandlerPlayServer.java:593) ~[NetHandlerPlayServer.class:?]
at net.minecraft.network.play.client.C08PacketPlayerBlockPlacement.processPacket(C08PacketPlayerBlockPlacement.java:74) ~[C08PacketPlayerBlockPlacement.class:?]
at net.minecraft.network.play.client.C08PacketPlayerBlockPlacement.processPacket(C08PacketPlayerBlockPlacement.java:122) ~[C08PacketPlayerBlockPlacement.class:?]
at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:241) ~[NetworkManager.class:?]
at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:182) ~[NetworkSystem.class:?]
... 5 more

 

 

Ah and you need to implement ITileEntityProvider so that Forge knows you need a TileEntity at the position.

Ahh thanks everyone! It works now!