!747

m {

  static int threads = 10;

  static int timeout = 500; // SHOULD be enough...

  static String ip = "127.0.0.1";

  p {

    final ExecutorService es = Executors.newFixedThreadPool(threads);

    print("Port scanning " + ip + " with timeout " + timeout + " ms in " + threads + " threads.");

    startTiming();

    new List<Future<Integer>> futures;

    for (int port = 1; port <= 65535; port++) {

      futures.add(portIsOpen(es, ip, port, timeout));

    }

    es.shutdown();

    new List<Integer> openPorts;

    for (final Future<Integer> f : futures) {

      int port = f.get();

      if (port != 0)

        openPorts.add(port);

    }

    stopTiming();

    System.out.println("There are " + openPorts.size() + " open ports on host " + ip + ": " + structure(openPorts));

  }

  public static Future<Integer> portIsOpen(final ExecutorService es, final String ip, final int port, final int timeout) {

    return es.submit(new Callable<Integer>() {

        @Override public Integer call() {

          try {

            Socket socket = new Socket();

            socket.connect(new InetSocketAddress(ip, port), timeout);

            print("Connected to " + ip + ":" + port);

            socket.close();

            return port;

          } catch (Exception ex) {

            return 0;

          }

        }

     });

  }

}