Java Tutorial/Servlet/HttpSessionBindingListener

Servlet Custom Session Binding Listener

import java.util.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class MyServlet extends HttpServlet {
   
  public void doGet(HttpServletRequest req, HttpServletResponse res)
                               throws ServletException, IOException {
    res.setContentType("text/plain");
    PrintWriter out = res.getWriter();
    // Get the current session object, create one if necessary
    HttpSession session = req.getSession();
    // Add a CustomBindingListener
    session.setAttribute("bindings.listener",
                         new CustomBindingListener(getServletContext()));
    out.println("This page intentionally left blank");
  }
}
class CustomBindingListener implements HttpSessionBindingListener {
  // Save a ServletContext to be used for its log() method
  ServletContext context;
  public CustomBindingListener(ServletContext context) {
    this.context = context;
  }
  public void valueBound(HttpSessionBindingEvent event) {
    context.log("[" + new Date() + "] BOUND as " + event.getName() +
                " to " + event.getSession().getId());
  }
  public void valueUnbound(HttpSessionBindingEvent event) {
    context.log("[" + new Date() + "] UNBOUND as " + event.getName() +
                " from " + event.getSession().getId());
  }
}