this is the onBlockPlacedBy code

onblockplacedby.java

 @Override
    public void onBlockPlacedBy(World worldIn,BlockPos pos,IBlockState state,EntityLivingBase placer,ItemStack stack)
    {
    	//grab settings from itemstack
    	if (worldIn == null)
    	{
    		System.out.println("EMPTY WORLD");
    		return;
    	}
    	if (pos == null)
    	{
    		System.out.println("EMPTY POS");
    		return;
    	}
    	if (stack == null)
    	{
    		System.out.println("EMPTY STACK");
    		return;
    	}
    	Boolean c,f;
    	NBTTagCompound n = new NBTTagCompound();
    	stack.readFromNBT(n);
    	c = n.getBoolean("comp");
    	f = n.getBoolean("frame");
    	TileEntityBarrel t;
    	TileEntity t1;
    	
    	try {
    	
    	t1 = (worldIn.getTileEntity(pos));
    	}
    	catch (NullPointerException e)
    	{
    		return;
    	} 
    	if (t1!=null)
    	{
    		t = (TileEntityBarrel)t1;
		if (t!=null)
		{
			t.init(c,f);
			this.updateBarrel((TileEntityBarrel)worldIn.getTileEntity(pos));
		}
    	
    	}
    	
    	//worldIn.getTileEntity(pos).init(stack.nbt
    }