Session invalidate or removing attribute

Question

what is the difference between session invalidate and removing the session attribute?

Answer 1

Hi,
Think of a session as a chalkboard, and different requests from the same user can use the chalkboard to post information for subsequent requests to see. Suppose you use session.setAttribute() to write two pieces of information on the session chalkboard, say, the user's name and credit card number. If you call session.removeAttribute(creditCard), then the credit card number will be erased from the session chalkboard. However, the user's name will still be written on the session chalkboard for subsequent requests to see. Subsequent requests from the same user can also post new information on the session chalkboard.
On the other hand, if you call session.invalidate(), that's like having a janitor rip the session chalkboard off the wall, break it over his knee, and dispose of it in the nearest dumpster. After that, requests can no longer see the user's name written on the chalkboard, and the requests do not have a session chalkboard to post additional information.