Spring security Redirection issue for already logged-in users

Question

While implementing spring security with my GWT based web application. I found that. Everything is working fine as expected, except the below fact:

I opened login.jsp

Answer 1

Alternatively you can create a Servlet Filter:

public class LoginPageFilter implements Filter
{
   public void init(FilterConfig filterConfig) throws ServletException   {
   }

   public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,   FilterChain filterChain) throws IOException, ServletException
   {
       HttpServletRequest request = (HttpServletRequest) servletRequest;
       HttpServletResponse response = (HttpServletResponse) servletResponse;

       if(request.getUserPrincipal() != null){ //If user is already authenticated
           response.sendRedirect("");// or, forward using RequestDispatcher
       } else{
           filterChain.doFilter(servletRequest, servletResponse);
       }
   }

   public void destroy() {
   }
}

web.xml:

LoginPageFilter com.xxx.xx.LoginPageFilter

    LoginPageFilter
    /login