CustomUnknownCommand

public class UnknowncmdListener implements Listener {
    @EventHandler(priority=EventPriority.HIGHEST)
    public void onPlayerCommandPreprocess(PlayerCommandPreprocessEvent event)
    {
        Player p = event.getPlayer();
        if ((!event.isCancelled()))
        {
            String command = event.getMessage().split(" ")[0];
            HelpTopic htopic = Bukkit.getServer().getHelpMap().getHelpTopic(command);
            if (htopic == null)
            {
                p.sendMessage(ChatColor.translateAlternateColorCodes('&', Cfg.prefix) + "§8Unbekannter Befehl!");
                event.setCancelled(true);
            }
        }
    }

}