Invalidating session in servlet
The minimal implementation provided by the servlet classes in JSDK 2.0 manages sessions through the use of persistent cookies.
A server can build on this base to provide additional features and capabilities.
void invalidate() Invalidates this session then unbinds any objects bound to it.
Due to the broken system, I can't vote once more for dupe.
1)When you are clicking on back button on browser you are getting previous page because of browser cache.
Do you have any other references to those objects on the session?
Browser is caching the previous pages, and when you click back button it is taking to previous cached page.