session.invalidate() clears the server side session.
you can solve the problem of duplicate submission by using session objects as tokens that are validated on that event.
Your browser stores its data (fields, etc) in form of cookies and autoloads the session information. Try clearing your cache/ form autoload information to solve that.
In simple words, when i click signout, it is forwarded to logoutservlet, there i have invalidate the session. now when i click back button of browser I get the document expired. That is ok. When i refresh sgain, the page loads. I have gone through the PRG patter, i am unable to implement it, as i am not using any framework. I dint get into my head and trying this since yesterday. . So i was saying that after the page is refreshed i could still see the old data, how come when the session is invalidated? Means this method invalidate is fooling us around?? Some one guide me to a easire way, only one problem and these many