[1.7.10]How to spawn entities with NBT data

[Mecblader]

Hello, I need tot be able to spawn an entity with existing nbt data. When I try to do this it crashes and says that it is a null pointer exception.

 

More info:

Basically I have a tile entity that scans for a random entity around it, and it saves that entity in its self. It then kills the entity and on game exit it saves the entity nbt by using these lines of code: 

     

NBTTagCompound compound2 = new NBTTagCompound();

      compound2.setString("id", EntityList.getEntityString(this.capturedEntity));

      this.capturedEntity.writeToNBT(compound2);

       

      compound.setTag("EntityData", compound2);

 

 

Then when I load it  I use these lines of code:

 

NBTTagCompound compound2 = (NBTTagCompound) compound.getTag("EntityData");

       

        if(compound2 != null) {

        this.targetEntity = (EntityLiving) EntityList.createEntityFromNBT(compound2, this.worldObj);

        this.capturedEntity = this.targetEntity;

        }

 

 

I tried printing the compound2 var and the entity obj out and they seem to display normal data, but when I try to spawn the entity in the world it crashes ans says that is is a Null Pointer Exception.

 

Full Code:

 

package mod.xtronius.htsm.tileEntity;

import java.util.ArrayList;
import java.util.List;

import mod.xtronius.htsm.entity.ai.EntityAIGoToCage;
import net.minecraft.block.Block;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityList;
import net.minecraft.entity.EntityLiving;
import net.minecraft.entity.ai.EntityAITempt;
import net.minecraft.entity.passive.EntityPig;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Items;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.nbt.NBTTagList;
import net.minecraft.tileentity.TileEntity;
import net.minecraft.util.AxisAlignedBB;

public class TileEntityCage extends TileEntity implements IInventory{

private ItemStack[] cageContents = new ItemStack[3];

private boolean isCageClosed = false;

private EntityLiving targetEntity;
private EntityLiving capturedEntity;

private ArrayList<Entity> removedEntities = new ArrayList<Entity>();

private int timer = 0;

@Override
public void updateEntity() {

	if(!this.worldObj.isRemote) {

		float seconds = 1.5f;
		int delay = (int) (seconds * 20);

		if(timer <= delay) timer++;
		else timer = 0;

//			this.targetEntity = null;
//			this.capturedEntity = null;
//			this.isCageClosed = false;

		//TODO Remove test code
//			System.out.println("Target: " + targetEntity);
//			System.out.println("Capture: " + capturedEntity);
//			System.out.println("IsClosed: " + isCageClosed);

		if(timer == delay) {

			//Checks to see if the inv slots are filled
			if(this.getStackInSlot(0) != null && this.getStackInSlot(1) != null && this.getStackInSlot(2) != null && !this.isCageClosed) { //TODO Create an item stack array for checking specific items

				//Gets the block at the tile entities' postion
				Block block = this.worldObj.getBlock(this.xCoord, this.yCoord, this.zCoord);

				//Gets the bounding box of the block obtained above, then it offsets it and expands it
				AxisAlignedBB aabb = AxisAlignedBB.getBoundingBox(block.getBlockBoundsMinX(), block.getBlockBoundsMinY(), block.getBlockBoundsMinZ(), block.getBlockBoundsMaxX(), block.getBlockBoundsMaxY(), block.getBlockBoundsMaxZ());
				AxisAlignedBB aabb1 = aabb.getOffsetBoundingBox(this.xCoord, this.yCoord, this.zCoord);
				AxisAlignedBB aabb2 = aabb1.expand(10, 10, 10);

				//Gets all entities within this bounding box
				List<EntityPig> list = this.worldObj.getEntitiesWithinAABB(EntityPig.class, aabb2);

				for(EntityPig entity : list) {

					// Breaks if the cage is closed, if the entity is already in another list or if there is already a targeted entity;
					if(isCageClosed || this.targetEntity != null || this.capturedEntity != null) break;

					if(!this.removedEntities.contains(entity)) {
						//Math for calculating the percentage chance
						double rand = Math.random();
						double randPercent = rand < 0.75 ? rand : 0.75;
						double item = 1.0;
						double subPercent = (item * randPercent) < 1.0 ? (item * randPercent) : 1.0;
						double finalPercent = 1 - subPercent;

						double rand2 = Math.random();
						//TODO Remove test code
						//Test Code
//						double rand2 = 1;

						if(rand2 > finalPercent) {

							//Try to send the entity to the tile entities location, closes the gate and set the entity as the target entity
							System.out.println("Working");
							entity.getNavigator().tryMoveToXYZ(this.xCoord, yCoord, zCoord, 1.0f);
							this.isCageClosed = true;
							this.targetEntity = entity;
							break;
						} else {
							this.removedEntities.add(entity);
							System.out.println("Fail");
						}
					}
				}
			} else if(this.isCageClosed) {

				int range = 3;

				if(this.targetEntity != null) {
					if(this.targetEntity.posX > this.xCoord - range && this.targetEntity.posX < this.xCoord + range) {
						if(this.targetEntity.posY > this.yCoord - range && this.targetEntity.posY < this.yCoord + range) {
							if(this.targetEntity.posZ > this.zCoord - range && this.targetEntity.posZ < this.zCoord + range) {
								this.capturedEntity = this.targetEntity;
							} else
								if(this.targetEntity != null) ((EntityPig) this.targetEntity).getNavigator().tryMoveToXYZ(this.xCoord, yCoord, zCoord, 1.0f);
						} else
							if(this.targetEntity != null) ((EntityPig) this.targetEntity).getNavigator().tryMoveToXYZ(this.xCoord, yCoord, zCoord, 1.0f);
					} else
						if(this.targetEntity != null) ((EntityPig) this.targetEntity).getNavigator().tryMoveToXYZ(this.xCoord, yCoord, zCoord, 1.0f);
				}

//					//Checks if the targeted entity is not alive, if so then reset the main variables
//					if(this.capturedEntity != null) 
//						if(this.capturedEntity.isDead) resetVars();
//					
//					//Checks if the captured entity is not alive, if so then reset the main variables
//					if(this.capturedEntity != null) 
//						if(this.capturedEntity.isDead) resetVars();
			}
		}
	}
}

private void resetVars() { this.isCageClosed = false; this.targetEntity = null; this.capturedEntity = null; }

@Override
public void readFromNBT(NBTTagCompound compound) {
        super.readFromNBT(compound);   
        
        NBTTagList list = compound.getTagList("Items", 10);
        this.cageContents = new ItemStack[this.getSizeInventory()];

        for (int i = 0; i < list.tagCount(); ++i) {
            NBTTagCompound compound1 = list.getCompoundTagAt(i);
            int j = compound1.getByte("Slot") & 255;

            if (j >= 0 && j < this.cageContents.length) {
                this.cageContents[j] = ItemStack.loadItemStackFromNBT(compound1);
            }
        }
        
        NBTTagCompound compound2 = (NBTTagCompound) compound.getTag("EntityData");
        
        if(compound2 != null) {
        this.targetEntity = (EntityLiving) EntityList.createEntityFromNBT(compound2, this.worldObj);
        	this.capturedEntity = this.targetEntity;
        }
        
        if(this.capturedEntity != null) {
        	this.isCageClosed = true;
        }
    }

@Override
    public void writeToNBT(NBTTagCompound compound) {
        super.writeToNBT(compound);
        NBTTagList list = new NBTTagList();
        
        for (int i = 0; i < this.cageContents.length; ++i) {
            if (this.cageContents[i] != null) {
                NBTTagCompound compound1 = new NBTTagCompound();
                compound1.setByte("Slot", (byte)i);
                this.cageContents[i].writeToNBT(compound1);
                list.appendTag(compound1);
            }
        }
        
        compound.setTag("Items", list);
        
        if(this.capturedEntity != null) {
        NBTTagCompound compound2 = new NBTTagCompound();
        compound2.setString("id", EntityList.getEntityString(this.capturedEntity));
        this.capturedEntity.writeToNBT(compound2);
        
        compound.setTag("EntityData", compound2);
        }
    }

@Override
public int getSizeInventory() { return 3; }

@Override
public ItemStack getStackInSlot(int slot) { return this.cageContents[slot]; }

@Override
public ItemStack decrStackSize(int p_70298_1_, int p_70298_2_) {
	 if (this.cageContents[p_70298_1_] != null)
        {
            ItemStack itemstack;

            if (this.cageContents[p_70298_1_].stackSize <= p_70298_2_)
            {
                itemstack = this.cageContents[p_70298_1_];
                this.cageContents[p_70298_1_] = null;
                this.markDirty();
                return itemstack;
            }
            else
            {
                itemstack = this.cageContents[p_70298_1_].splitStack(p_70298_2_);

                if (this.cageContents[p_70298_1_].stackSize == 0)
                {
                    this.cageContents[p_70298_1_] = null;
                }

                this.markDirty();
                return itemstack;
            }
        }
        else
        {
            return null;
        }
}

@Override
public ItemStack getStackInSlotOnClosing(int slot) { return this.cageContents[slot]; }

@Override
public void setInventorySlotContents(int slot, ItemStack stack) { this.cageContents[slot] = stack; }

@Override
public String getInventoryName() { return "Cage"; }

@Override
public boolean hasCustomInventoryName() { return false; }

@Override
public int getInventoryStackLimit() { return 64; }

@Override
public boolean isUseableByPlayer(EntityPlayer player) { return this.worldObj.getTileEntity(this.xCoord, this.yCoord, this.zCoord) != this ? false : player.getDistanceSq((double)this.xCoord + 0.5D, (double)this.yCoord + 0.5D, (double)this.zCoord + 0.5D) <= 64.0D; }

@Override
public void openInventory() {}

@Override
public void closeInventory() {}

@Override
public boolean isItemValidForSlot(int slot, ItemStack stack) { return true; }
}

 

[Whov]

Could you post your crash log?