I thought of how I could use these listeners in my mock application and this might help you:
(I havent tried yet, so I'm not too sure if it will work. ranchers, correct me if im wrong)
My application is one where a user can buy sell etc.. and well there is a shopping cart too.
Whenever a user visits my site, a session would get created.
This, my HttpSessionListener would come to know and in its sessionCreated() method I would have a
If that user signs in, I would set an attribute like "signedIn" with a value say "true" in the session.
The attributeAdded() method in HttpSessionAttributeListener would check if the added attribute is "signedIn" and in that case do
When the user session expires or invalidates, I probably would want all his shoppingCart details to be persisted in the database.
So the valueUnbound() method in HttpSessionBindingListener would come in handy here.