//server:

public static void main(String[] args) throws IOException, ClassNotFoundException {
        new Thread(new Server()).start();
    }

    @Override
    public void run() {
        Settings settings = SettingsDAO.getInstance().getSettingsFromXML("C:/users/pietro/Desktop/kalambury/settings.xml");
        System.out.println("Awaiting for connection");
        try (ServerSocket serverSocket = new ServerSocket(settings.getPort())) {
            while (true) {
                if (playersOnline % settings.getMaxPlayersInRoom() == 0) {
                    new Thread(new Room(this, serverSocket)).start();
                    playersOnline++;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


//room:

public class Room implements Runnable {

    private ServerSocket socket;
    private Server server;
    private List<PrintWriter> writers;

    public void run() {
        writers = new ArrayList<>();
        System.out.println("New room!");
        while (true) {
            try {
                new Thread(new PlayerHandler(server, this, socket.accept())).start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    Room(Server server, ServerSocket socket) {
        this.server = server;
        this.socket = socket;
    }

    public synchronized List<PrintWriter> getWriters() {
        return writers;
    }

}