Session variable not set in Spring

Question

Hello, I have a Spring controller which is putting a variable in the session:

public class LoginFormController extends SimpleFormController {

    public ModelAndView onSubmit(HttpServletRequest request, 
            HttpServletResponse response, Object command) throws Exception {

            request.getSession().setAttribute("authenticated_user", "authenticated_user");
    }
}

I then have a HandlerInterceptor. In the preHandle method, I check for the variable in the session:

public boolean preHandle(HttpServletRequest request,
                                      HttpServletResponse response,
                                      Object handler) throws Exception {

        /* first, check if the requested view even required authentication */
        if (isAuthenticationRequired(request)) {

            /* check to see that user is logged in */
            if (null == request.getSession().getAttribute("authenticated_user")) {
                forwardToLogonPage(request, response);
                return false;
            }
            /* all is ok - pass the request on */
            return true;
        }
        /* all is ok - pass the request on */
        return true;
    }

The problem is it seems that the session variable is not being set since request.getSession().getAttribute("authenticated_user")) is always resolving to null.

Any ideas plz?

Thanks, Krt_Malta