SignonInterceptor Spring

public class SignonInterceptor extends HandlerInterceptorAdapter {  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)      throws Exception {    UserSession userSession = (UserSession) WebUtils.getSessionAttribute(request, "userSession");    if (userSession == null) {      String url = request.getServletPath();      String query = request.getQueryString();      ModelAndView modelAndView = new ModelAndView("SignonForm", "message", "You must be signed on to access this page.");      if (query != null) {        modelAndView.addObject("signonForwardAction", url + "?" + query);      } else {        modelAndView.addObject("signonForwardAction", url);      }      throw new ModelAndViewDefiningException(modelAndView);    }    return true;  }}