The "http protocol" is a stateless response or request based protocol.
You may contain the state information between different page requests as given below:
HTTP Sessions are the recommended useful approach. A session finds the requests that originate from the same browser in the mean while the period of conversation. All the servlets may share the similar session. The JSESSIONID is started by the server and may be passed to client through URL re-writing (if cookies are turned off), cookies or built-in SSL process. Care could be given to minimize size of objects stored in session and objects stored in session could be serializable. In a Java servlet the session may be retrieve as given:
HttpSession session = request.getSession(true); //gives a current session or a new session
//To get/put a value in/from the session
Name name = new Name("Parker");
session.setAttribute("lastname", name); //session.putValue(...) is deprecated as of 2.2
session.getAttribute("lastname");//get a value. session.getValue(...) is deprecated
//If a session is no longer needed e.g. user has logged out, etc then it may be invalidated. session.invalidate();
//you may also set the session inactivity lease period on every session basis session.setMaxInactiveInterval(300);
