SpringMVC Session Timeout - Redirect to a Special JSP - spring

Question

I've looked everywhere but haven't found a simple solution.
We have a special JSP, timeout.jsp, that needs to be shown whenever a SpringMVC module intercepts an invalid session action. The timeout is already configured in web.xml and works correctly.
Previously in Struts, it was a matter of defining a forward and intercepting dispatchMethod,
<forward name="sessionTimeout" path="/WEB-INF/timeout.jsp" redirect="false" />
#Override
protected ActionForward dispatchMethod(final ActionMapping mapping, final ActionForm form,
final HttpServletRequest request, final HttpServletResponse response, final String name)
throws Exception {
//...
if (!isSessionValid())
return mapping.findForward("sessionTimeout");
}
But how would you implement a catch-all solution in SpringMVC modules?
All my SpringMVC URLs come to this servlet mapping, *.mvc:
<servlet-mapping>
<servlet-name>mvc-dispatcher</servlet-name>
<url-pattern>*.mvc</url-pattern>
</servlet-mapping>
Anything that sends a URL with this pattern should be cross-checked for session validity and if invalid, redirected to timeout.jsp.
NOTE
The solution given here (https://stackoverflow.com/a/5642344/1005607) did not work:
<web-app>
<error-page>
<exception-type>org.springframework.web.HttpSessionRequiredException</exception-type>
<location>/index.jsp</location>
</error-page>
</web-app>
There's a NullPointerException in my SpringMVC Form Code even before any kind of SessionRequiredException, as soon as I try to access the session. I need to globally protect against these NullPointerExceptions.

Answer 1

My final solution: an old-fashioned Filter. It works for me, no other simple solution available.
web.xml
<filter>
<filter-name>spring_mvc_controller_filter</filter-name>
<filter-class>myapp.mypackage.SpringMVCControllerFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>spring_mvc_controller_filter</filter-name>
<url-pattern>*.mvc</url-pattern>
</filter-mapping>
SpringMVCControllerFilter
public class SpringMVCControllerFilter implements Filter
{
#Override
public void destroy() {
// TODO Auto-generated method stub
}
#Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpSession session = request.getSession(false);
if (session.isValid() && !session.isNew())
{
chain.doFilter(request, response);
}
else
{
request.getRequestDispatcher("/WEB-INF/jsp/sessionTimeout.jsp").forward(request, response);
}
}
#Override
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
}
}