title: Java HttpURLConnection no cookies at login
body: <p>I'm currently trying to do a login with HttpURLConnection and then get the session cookies...</p>
  
  <p>I already tried that on some test pages on my own server, and that works perfectly. When i send <code>a=3&amp;b=5</code> i get <code>8</code> as cookie (PHP page adds both together)!
  But when i try that at the other page, the output is just the page as if I just sent nothing with POST :(</p>
  
  <p>General suggestions for improvement are welcome! :)</p>
  
  <p>My Code:</p>
  
  <pre><code>HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
  conn.setDoInput(true);
  conn.setDoOutput(true);
  conn.setRequestMethod("POST");
  conn.setRequestProperty("useragent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20100101 Firefox/17.0");
  conn.setRequestProperty("Connection", "keep-alive");
  DataOutputStream out = new DataOutputStream(conn.getOutputStream());
  out.writeBytes("USER=tennox&amp;PASS=*****");
  out.close();
  
  BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
  String line;
  String response = new String();
  while ((line = in.readLine()) != null) {
      response = response + line + "\n";
  }
  in.close();
  
  System.out.println("headers:");
  int i = 0;
  String header;
  while ((header = conn.getHeaderField(i)) != null) {
      String key = conn.getHeaderFieldKey(i);
      System.out.println(((key == null) ? "" : key + ": ") + header);
      i++;
  }
  String cookies = conn.getHeaderField("Set-Cookie");
  System.out.println("\nCookies: \"" + cookies + "\"");
  </code></pre>