This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
An HttpSessionAttributeListener is normally implemented by an non-attribute class when an associated object needs to know that an attribute has been added to, replaced, or removed from a given session.
An HttpSessionBindingListener is normally implemented by an attribute class when an associated object needs to know that it is bound to or unbound from a session.