I am not sure I fully understand your issue, but here is my input.
I would setup a ServletFilter rather than do everything in JSP.
As an example, if you have pages in a private area, you define a ServletFilter that runs when the URL contains the
string 'PRIVATE'.(/myapp/PRIVATE/destinationpage.jsp)
In that filter, you check to see if the session has expired. If it has, you send the user to login.jsp. If the session is still valid, then you pass them through to the requested page.
login.jsp then always sends users to home.jsp if the login is successful.