HttpURLConnection and valid cookies

Question

Hi,
I have implemented a web server with a login page to authenticate a user.
When the browser has not send a valid cookie, the server redirects to the
login page, where the user can fill a form to post the username and password.
I am implementing a java stand-alone client to access this web server. I use
the HttpURLConnection class for this.
First, i authenticate the user sending a post request with the login and
password. The server responds with a cookie. To access other resources in
the server i send the cookie in each request.
My problem is: i am using java class HttpURLConnection. When the cookie
is not valid, the server redirects to the login page, but i have not
found a way to know about it without parsing the response html. I get the http
header fields but there is no info about this.
Thanks in advance

Answer 1

You should extraxt the sessionID from the cookie, when logging on to the system.
From then on, pass the session ID to all further connections.
You can obtain the session-ID like this:
public void retrieveSessionID() {
               String key = "";
               String id = "";
               try {
                 URL url = new URL ( "http://localhost/yourapplication/logon.jsp?username=Homer&password=donut);
                 URLConnection urlConnection = url.openConnection();
                 if (urlConnection != null)
                      for (int i = 1;(key = urlConnection.getHeaderFieldKey(i)) != null; i++)
                           if (key.equalsIgnoreCase("set-cookie"))
                                id = urlConnection.getHeaderField(key);
                                id = id.substring(0, id.indexOf(";"));
                           }     //if
                      }     //for
                 }     //if
               } catch (IOException e) {
                                                                      e.printStackTrace();
               }     //catch
                 this.jSessionId = id;
     }     //getSessionIDAnd then make every connection like this:
URL url = new URL("http:......");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
                connection.setRequestProperty("Cookie", this.jSessionId);
                connection.connect();                Hope I could help!
Greetings
Stef