Web Listeners ( Servlets/Session)

There are 7 Listeners that are important  for servlet and session 

1 . ServletContextListener

public void contextDestroyed(ServletContextEvent arg0) {}

public void contextInitialized(ServletContextEvent arg0) {}

2. SessionListener / HttpSessionListener

sessionCreated(HttpSessionEvent evt ){}

sessionDestroyed(HttpSessionEvent evt) {}

HttpSessionActivationListener
sessionDidActivate(HttpSessionEvent ) {}
sessionWillPassivate(HttpSessionEvent ) {}

3. ServletContextAttributeListener / HttpSessionAttributeListener / ServletRequestAttributeListener 

attributeAdded()

attributeRemoved()

attributeReplaced()

in attributelistener the argument to the methods will be different as per the  interface.

for HttpSessionAttributeListener arg will be HttpSessionSessionBindingEvent.

4. HttpSessionBindingListener will be implemented by attribute

valuebound(HttpSessionBindingListener )

valueunbound(HttpSessionBindingListener )