URL url = new URL("http://jrserver:8888");
URLConnection uc = url.getConnection();
if (uc instanceof HttpURLConnection) {
  HttpURLConnection huc = (HttpURLConnection)uc; 
  //set use POST method.
  huc.setRequestMethod("POST");
  huc.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
  huc.setDoOutput(true);
 
  //write the HTTP query to the output stream.
  OutputStreamWriter writer = new OutputStreamWriter(huc.getOutputStream());
  writer.write("jrs.cmd=jrs.get_subnodes");
  writer.close();
  huc.getHeaderField(0);
 
  //get the response content from the server.
  InputStream inStream = uc.getInputStream();
  if (inStream != null) {
    BufferedReader reader = new BufferedReader(new InputStreamReader(inStream));
    String inputLine;
    while (null != (inputLine = reader.readLine())) {
      System.out.println(inputLine);
    }
  }
}