[...]

                log.info(plugin.getName() + ": Permissions plugin not found. " + plugin.getName() + " will work for everyone.");

[...]

    @Override
    public boolean onCommand(CommandSender sender, Command cmd,
            String commandLabel, String[] args) {
        Player player = (Player) sender;
        if (commandLabel.equalsIgnoreCase("hat")) {
            if (Permissions == null || Permissions.has(player, "simple.hat")) {
                if (player.getItemInHand().getTypeId() == 0) {
                    player.sendMessage(ChatColor.YELLOW
                            + "You must have something to put on your head.");
                    return true;
                } else {
                    ItemStack itemHand = player.getItemInHand();
                    PlayerInventory inventory = player.getInventory();
                    ItemStack itemHead = inventory.getHelmet();
                    inventory.remove(itemHand);
                    inventory.setHelmet(itemHand);
                    if (itemHead.getTypeId() != 0) {
                        inventory.setItemInHand(itemHead);
                    }
                    player.sendMessage(ChatColor.YELLOW + "Item successfuly put on your head.");
                    return true;
                }
            }
        }
        return false;
    }