Listing 7. This deployment descriptor for our user counter example is required for the application to work.

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app
   PUBLIC "-//Sun Microsystems, Inc.//
   DTD Web Application 2.3//EN"
   "http://java.sun.com/j2ee/dtds/
   web-app_2_3.dtd">

<web-app>
   <listener>
      <listener-class>
         SessionLifeCycleEventDemo
      </listener-class>
   </listener>
   <servlet>
      <servlet-name>UserCounter</servlet-name>
      <servlet-class>
         UserCounterServlet
      </servlet-class>
   </servlet>
</web-app>