There are 8 Listeners to remember. We know there are attributes in 4 scopes because we know how to Pick the Right Scope Automatically, but you can’t listen to Page attributes, it doesn’t make sense, so that leaves us with RSA; Request, Session and Application. These tally with the objects:

  • ServletRequest
  • HttpSession
  • ServletContext

There is a Listener for each of these objects for lifecycle events, and for attribute events, so that gives us 6 of the Listener Interfaces:

  • ServletRequest[Attribute]Listener
  • HttpSession[Attribute]Listener
  • ServletContext[Attribute]Listener

HttpSession gets the 2 extra interfaces:

  • HttpSessionBindingListener – Attribute objects implement this if they themselves want to know whenthey are [un]bound
  • HttpSessionActivationListener – Listen here to have a nose when the session is gallivanting around


There are just 6 events, one for each lifecycle event:

  • ServletRequestEvent
  • HttpSessionEvent
  • ServletContextEvent

and one for each attribute-related event:

  • ServletRequestAttributeEvent
  • HttpSessionBindingEvent – (It’s easy to remember this black sheep because its initials rhyme with the worlds local bank HSBE)
  • ServletContextAttributeEvent