Helmet and AIR?

I got a problem. I'm developing a "hat"-plugin, which allows you to add the ItemInHand to the your helmet. Problem was, that an internal server error occures :/

Can someone help me?

My code



Console

You my friend got a nullpointer exeption, so something in your code returns null, let me have a look...

line 33 and 40 and 35 prob return null

You should do a null check on it, like
if(item != null){
if(item == what you want{//Your code here}
}

@XbannisherX

Thanks your help! I changed the code but...

Code
http://prntscr.com/g1603

Error
http://prntscr.com/g164e

Here I had an old hat command and I updated to your needs.

Code:

    private boolean handleHat(CommandSender sender, String[] args)
    {
        Player player = (Player) sender;
 
        if (player.getItemInHand().getType() != Material.AIR)
        {
            ItemStack itemHand = player.getItemInHand();
            PlayerInventory inventory = player.getInventory();
            ItemStack itemHead = inventory.getHelmet();
            inventory.removeItem(itemHand);
            inventory.setHelmet(itemHand);
            inventory.setItemInHand(itemHead);
            player.sendMessage(ChatColor.GREEN
                    + "Item successfuly put on your head.");
            player.sendMessage(ChatColor.AQUA
                    + "Remember to check your helment slot to make sure you didnt put more then 1 of that item!");
            return true;
        }
        else
        {
            player.sendMessage(ChatColor.RED
                    + "You must have something to put on your head!");
            return true;
        }
    }

Remember to check if it is a player by checking if instanceof Player. If you try do to it in the console you will get an error saying you cant cast entity player to the console.

There are so many of these, you should try to make yours cooler than others.