I have the main code, with an item that changes a block (like a hoe)

How would one spawn an item on the ground. Like if I use a hoe on dirt, it will spawn a block of dirt on the ground.

I also want it to fountain out of the top of the block (like 4 different items fly out the top)

spawning it shouldnt be too bad, player.dropItemWithOffset() should do it just create a new itemstack with that item to do it.

but making it fountain up , no clue.

world.spawnEntityInWorld(new EntityItem(world, x, y, z, new ItemStack(Blah item here)));

Should do what you want

A better solution

	
public boolean onItemUse(ItemStack item, EntityPlayer player, World world, int x, int y, int z, int par7, float xFloat, float yFloat, float zFloat)
{
	//Can the player alter this block?
	if (!player.canPlayerEdit(x, y, z, par7, item)) {
		return false;
	}
	//Was the block clicked on a dirt block?
	if(world.getBlockId(x, y, z) == Block.blockDirt.blockID){

                 world.spawnEntityInWorld(new EntityItem(world, x, y, z, new ItemStack(Blah item here)));
		 return true;
	}
	 return false;
}

This goes in your item class