Java servlet - Session cleanup (HttpServletRequest)

Question

General question about java servlets and the best way to handle requests. If I hit my doGet method from a remote server request:

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
  ....
  <do work here>
  ....
  kill(request);
}

private void kill(HttpServletRequest request) {
//How do I kill the user session here?
}

After I process the request at my end and generate my output to the requester, I want to basically "kill" their session. Currently, that session lingers and thus eats up memory. Then once the max is reached, all other calls are timed out.

I tried creating a HttpSession object using the request object, but got the same results:

HttpSession session = request.getSession();
session.invalidate();

Answer 1

HttpSession session = request.getSession(false);
if (session != null) {
    session.invalidate();
}

is the proper way to go as suggested by the documentation. A new session will be created once the client sends a new request.

You mentioned that your sessions still take up memory. Do you have any other references to those objects on the session?

You also might want to have a look at: Servlet Session behavior and Session.invalidate

Answer 2

you can remove an attribute from a session using

session.removeAttribute("attribute name");

Answer 3

Try with

session = request.getSession(false); // so if no session is active no session is created
if (session != null)
  session.setMaxInactiveInterval(1); // so it expires immediatly

Answer 4

If you dont want Session behavior ie, having state between multiple requests. Why do you want to create/use session at all. Do not create session or do not store anything in the session.

To make sure that your code is not using session, write a request wrapper which will override getSession() methods.

Answer 5

Set a time-out period in web.xml