[HTTPS] post returning null

Question

Hi, I've been trying to program something that can log me into the school website automatically, with the intention to synchronize every interesting thing.
Now, I've got the https login page correct, and found a hidden element in the login form that is always required. But that still does not work...
Anyhow, here's some code I'm talking about, the result of the post is " 1null" (Meaning one line, and after that end of stream)
public void post_url (String arg, String file) {
    try {
      Security.addProvider (new com.sun.net.ssl.internal.ssl.Provider ());
      SSLSocketFactory factory = (SSLSocketFactory)SSLSocketFactory.getDefault ();
      SSLSocket socket = (SSLSocket)factory.createSocket (host, port);
      Writer out = new OutputStreamWriter (socket.getOutputStream ());
      out.write ("POST http://" + this.host + "/" + file + " HTTP/1.1\r\n");
      out.write ("Host: " + host);
      out.write ("User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.8) Gecko/20071030 Firefox/2.0.0.8");
      out.write ("Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5");
      out.write ("Accept-Language: en-us,en;q=0.5");
      out.write ("Accept-Encoding: gzip,deflate");
      out.write ("Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7");
      out.write ("Keep-Alive: 300");
      out.write ("Connection: keep-alive");
      out.write ("Referer: https://***/cas/login?service=https%3A%2F%2Fidp.***%2Fshibboleth-idp%2FSSO%3Fshire%3Dhttps%253A%252F%252F***%252FShibboleth.sso%252FSAML%252FArtifact%26time%3D1195915147%26target%3Dcookie%26providerId%3Dhttps%253A%252F%252F***");
      out.write (this.cookie);
      out.write ("Content-Type: application/x-www-form-urlencoded");
      out.write ("Content-Lenght: " + arg.length ());
      out.write (arg);
      out.flush ();
      BufferedReader in = new BufferedReader (new InputStreamReader (socket.getInputStream ()));
      String total = "";
      String lijntje = "";
      int c = 1;
      do {
        lijntje = in.readLine ();
        total += lijntje;
        System.out.print (" " + c);
        c++;
      } while (lijntje != null);
      System.out.println (total);
      out.close ();
      in.close ();
      socket.close ();
    } catch (IOException e) {
      System.err.println (e);
}Which is called by:
this.connection.post_url ("username=" + this.user + "&password=" + this.pass + "&lt=" + lt + "&_currentStateId=&_eventId=submit", "***");For reasons of privacy, I've removed any link to the website... I hope anyone can help me out here, for I'm puzzled beyond my knowledge...

Answer 1

So, I've used your hint and formed this code:
      URL bla = new URL ("https://" + this.host + file);
      HttpURLConnection blacon = (HttpURLConnection)bla.openConnection ();
     // HttpURLConnection
      blacon.setRequestMethod ("POST");
      blacon.setDoOutput (true);
      blacon.setDoInput (true);
      blacon.setRequestProperty ("Content-type", "application/x-www-form-urlencoded");
      DataOutputStream io1 = new DataOutputStream (blacon.getOutputStream ());
      io1.writeBytes (arg);
      io1.flush ();
      io1.close ();
      DataInputStream io2 = new DataInputStream (blacon.getInputStream ());
      String str;
    while (null != ((str = io2.readLine())))
    System.out.println (str);
    //textArea.appendText (str + "\n");
io2.close ();It's not the purest code, but for sake of testing.
However, I've got no proof what-so-ever that it really is posting something, for I just get the page as if I were just doing a get request without the post args...