Help with Array Lists.

So I need help with adding a player to an ArrayList.
My ArrayList is Naughty.
The Player is Santa.
What is wrong with this?

Code:

Naughty.add(Santa.getName())

Here is where I made the ArrayList:

Code:

public ArrayList<Player> Naughty = new ArrayList<Player>();

Here is the whole section that uses this ArrayList:

Code:

    public void onPlayerJoin(PlayerJoinEvent login) {
        Player Santa = login.getPlayer();
            if(!(Naughty.contains(Santa.getName())))    {
                Santa.sendMessage("Merry Christmas from KaiBB, " + Santa.getName() + ", here is your present! A diamond pickaxe!");

                final Inventory inv = Santa.getInventory();
                inv.addItem(new ItemStack(Material.DIAMOND_PICKAXE, 1));
                Naughty.add(Santa.getName());
            }

If you could not tell by the codes, I want it to only do these two functions once per player. Thanks!

 

public ArrayList<Player> Naughty = new ArrayList<Player>();

should be

public ArrayList<String> Naughty = new ArrayList<String>();

 

Ohh. Thank you. And the part where I add Santa.getName() is fine?

 

Santa's song about lists aside, you should be using a Set for keeping track of who is Naughty or not. Searching for whether someone is naughty is much slower on a List, because every name up to the match must be checked.

 

Well I just named it Naughty for fun. It's really a list of players who have already received a gift. That way they don't get a gift every time they join!

 

Do you understand your mistake?
Santa.getName(); returns a string.
But your ArrayList<Player> is for Players, not for Strings.

 

Errr, note that the list will reset on server reboot or reload.

 

Change List to Set and ArrayList to HashSet. Nothing else
I REALLY suggest you learn more java

 

Although these types of collections structures transcend Java and is applicable to all programming. Although i suppose each languages' implementation has their quirks.