Java examples on javax.servlet
- How do I get servlet request URL information?
- How do I get web application context path?
- How do I read text file in Servlet?
- How do I get a spring's bean from a servlet?
- How do I get parameter names from servlet request?
- How do I get client IP and hostname in Servlet?
- How do I create a HelloWorld Servlet?
- How do I invalidate user's session?
- How do I count number of online users?
- How do I read servlet context initilization parameters?
- How do I create a hit counter servlet?
- How do I read request parameter from servlet?
- How do I create zip file in Servlet for download?
- How do I get servlet request headers information?
- How do I check if parameter is exists in servlet request?
- How do I send a response status in servlet?
- How do I get my web application real path?
- How do I set the maximum age of a cookie?
- How do I get a notification when session attribute was changed?
- How do I read servlet init parameter?
- How do I share object or data between users in web application?
- How do I know session last access time?
- How do I capture session creation and removal events?
- How do I read cookie in Servlet?
- How do I send a cookie in Servlet?
- How do I define welcome files for web application?
- How do I define a servlet with @WebServlet annotation?
- How do I define a filter using @WebFilter annotation?
- How do I obtain ServletContext of another application?
- How do I delete a cookie in Servlet?
How do I capture session creation and removal events?
The Servlet specification define an HttpSessionListener interface that can be implemented if we want to listen to session creation and removal events.
package org.kodejava.example.servlet;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import java.util.Date;
public class MySessionListener implements HttpSessionListener {
// Notification that a new session was created
public void sessionCreated(HttpSessionEvent event) {
HttpSession session = event.getSession();
System.out.println("New session created : " + session.getId());
System.out.println("Session creation time: " + new Date(session.getCreationTime()));
}
// Notification that a session was invalidated
public void sessionDestroyed(HttpSessionEvent event) {
HttpSession session = event.getSession();
System.out.println("Session destroyed : " + session.getId());
}
}
To make the listener works you need to configure in the the web.xml file. Below in a cofiguration example for our listener.
<listener>
<listener-class>org.kodejava.example.servlet.MySessionListener</listener-class>
</listener>