static int isPortOpen_timeout = 500;
static boolean isPortOpen(int port) {
  try {
    Socket socket = new Socket();
    socket.connect(new InetSocketAddress("127.0.0.1", port), isPortOpen_timeout);
    //print("Connected to " + ip + ":" + port);
    socket.close();
    return true;
  } catch (Exception ex) {
    return false;
  }
}