title: Java secure session
body: <p>Whenever you authenticate, your application should change the session identifier it uses. This helps to prevent someone from setting up a session, copying the session identifier, and then tricking a user into using the session. Because the attacker already knows the session identifier, they can use it to access the session after the user logs in, giving them full access. This attack has been called "session fixation" among other things. How can i change the session id once the user login to the system ? </p>