Java EE 8 Application Development

Servlet listeners

During the lifetime of a typical web application, a number of events take place, such as HTTP requests getting created or destroyed, request or session attributes getting added, removed or modified, and so on and so forth.

The servlet API provides a number of listener interfaces we can implement in order to react to these events. All of these interfaces are in the javax.servlet package, and the following table summarizes them:

Listener interface	Description
ServletContextListener	Contains methods for handling context initialization and destruction events.
ServletContextAttributeListener	Contains methods for reacting to any attributes added, removed, or replaced in the servlet context (application scope). ...