Preventing the User from going back to the main page after logging out.

Question

Hi all,
In my project I want to prevent the User from going back to the Main page, by clicking the back button of the browser, after the user has loggged out.I had invalidated the session so the user will not be able to do any operations, but he can vew the infos. I want to redirect to the login page if the user tries to go back using the back button after he has logged out.
I tried the same in this forum after loging out. Surprisingly it is the same. I can browse through all the operations i did even after logging out from here.
Is it not possible to do that in Servlets?Could somebody help?
Thanks,
Zach.

Answer 1

Hi,
You can use a servlet filter to do this , as it can interceptany request to your application you can decide to allow user access or not to any page/servlet.
public class Test implements Filter{
     public void destroy() {
     public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException,
               ServletException {
          System.out.println("filter");
          HttpServletRequest request = (HttpServletRequest) arg0;
          if(!request.getRequestURI().contains("index")){ // set condition that will be checked to verify if the user is logged in
               System.out.println("redirecting ... ");
               RequestDispatcher d = arg0.getRequestDispatcher("/index.jsp");
               d.forward(arg0, arg1);
          arg2.doFilter(arg0, arg1);
     public void init(FilterConfig arg0) throws ServletException {
}in you web.xml add :
<filter>
          <filter-name>test</filter-name>
          <filter-class>test.Test</filter-class>
     </filter>
     <filter-mapping>
          <filter-name>test</filter-name>
          <url-pattern>/*</url-pattern>
     </filter-mapping>