public class Main extends JavaPlugin implements Listener{

    private Map<String, Boolean> map = new HashMap<String, Boolean>();

    public void onEnable() {
        this.getCommand("stan").setExecutor(this);
        this.getServer().getPluginManager().registerEvents(this, this);
    }
    
    @EventHandler
    public void onJoin(PlayerJoinEvent e){
        if(!map.containsKey(e.getPlayer().getName())){
            map.put(e.getPlayer().getName(), false)
        }
    }

    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        Player p = (Player) sender;
        if(cmd.getName().equalsIgnoreCase("stan")) {
            p.sendMessage("Stan: " map.get(e.getPlayer().getName().toString().replace("true", "wlaczone").replace("false", "wylaczone")));
            map.put(e.getPlayer().getName(), !map.get(e.getPlayer().getName()));
        }
        return false;
    }
}