How can I remove inventory items in a Bukkit plugin?

Question

I am making a Bukkit plugin that takes the player to a "FunZone" and allows them to do just about anything. I don't want data transferred between the two worlds. So far I have got most everything stopped. Here's the problem code:

            Integer normInvSize = player.getInventory().getSize();
            Integer i = 0;
            for (i=0; i<normInvSize; i++) {
                ItemStack item = player.getInventory().getItem(i);
                pConfig.set(player.getWorld().getName()+"Inv."+i.toString()+".amount", item.getAmount());
                Short durab = item.getDurability();
                pConfig.set(player.getWorld().getName()+"Inv."+i.toString()+".durabillity", durab.intValue());
                pConfig.set(player.getWorld().getName()+"Inv."+i.toString()+".type", item.getTypeId());
                player.getInventory().removeItem(new ItemStack(item.getType(), item.getAmount()));
            }

I have everything set up how I want it but I get stray items following me between the worlds. The line

player.getInventory().removeItem(new ItemStack(item.getType(), item.getAmount()));

does not remove all of the inventory. I want some code that will remove all inventory items (I've handled armor already). I already have a way to restore the inventory later, but my code currently won't remove everything. For example I can end up transfering some stone tools from the "FunZone" to the normal world, which I don't want.

Answer 1

You can't clear a list while you're iterating over it, at least not in this way. Let me show you this, we'll assume a list with 5 items:

1. List: 5, Index: 0
2. List: 4, Index: 1
3. List: 3, Index: 2
4. Break condition already met. 2 Items remaining.

What you want to do is clear the whole inventory after you've iterated over it.

// Cache the inventory instead of a number you'll only use once.
PlayerInventory inventory = player.getInventory();

// Cache the world name
String worldName = player.getWorld().getName();

// Use a foreach instead. Looks better.
for (ItemStack stack : inventory.getContents()) {
    // More cache, String concetanations are expensive!
    String start = worldName + "Inv." + Integer.toString(i);

    pConfig.set(start + ".amount", stack.getAmount());
    pConfig.set(start + ".durability", stack.getDurability().intValue()); // Please be aware that I fixed a typo in durability
    pConfig.set(start + ".type", stack.getTypeId());
}

// And now clear the inventory
inventory.clear();

Also, I don't know what pConfig is, but the structure smells broken if you need save stuff like this. You use an Object-Oriented language, so if you need to split strings to get something, you're doing something wrong. You might want to rewrite that...thing.

For further infos please go to Stack Overflow, f.e.: Efficient Equivalent to Removing while Iterating a Collection