Serve login page JSP on failed login attempt - spring-mvc

Question

My login form is located at /account/login. GET requests to this URL cause a request handler to be invoked, which returns account/login as the logical view name, and /WEB-INF/jsp/account/login.jsp gets served.
#RequestMapping(value="/account/login", method=RequestMethod.GET)
public String login()
{
return "account/login";
}
POST requests to /account/login invoke my UsernamePasswordAuthenticationFilter, so the login form is both served by (via GET) and submits to (via POST) /account/login.
This all works great.
However, in the event of a login failure I would like /WEB-INF/jsp/account/login.jsp to be served without doing an HTTP redirect, i.e. POSTing a bad username/password to /account/login would serve /WEB-INF/jsp/account/login.jsp.
I've tried overriding SimpleUrlAuthenticationFailureHandler.onAuthenticationFailure() like so:
#Override
public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException
{
request.getRequestDispatcher("account/login").forward(request, response);
}
However, this results in a 404 response when POSTing a bad username/password to /account/login.
I've tried passing in /WEB-INF/jsp/account/login.jsp, /account/login.jsp, and many other combinations to ServletRequest.getRequestDispatcher() but nothing seems to work.
Any ideas what I'm doing wrong? I have a feeling the dispatcher is trying to dispatch to my request handler rather than the JSP itself, but I'm not familiar enough with the entire JSP dispatch workflow to know how to get around that.

Answer 1

I accidentally figured this out shortly after posting the question. Answering here in case it becomes of some use to someone else down the road.
In the onAuthenticationFailure(), I passed /account/login to getRequestDispatcher(), and I also called include() rather than a forward(), like so:
#Override
public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException
{
request.getRequestDispatcher("/account/login").include(request, response);
}
Submitting the login form with an incorrect username and/or password causes the login form JSP to be served as the POST's response, and submitting the correct username/password still invokes my UsernamePasswordAuthenticationFilter!!