Spring security “forward:” directive can't forward to login form

Question

After a user creates their account, I want to log that user on automatically.

I have standard form logins being handled by Springs filter on /postlogin.

Answer 1

Spring authentication via REST (Jersey)

Just to illustrate @David's answer (simplified as much as possible):

@POST
@Path("login")
public Response login(@FormParam("login") String login, @FormParam("pass") String pass)
{
    if (yourCheck(login, pass))
    {
        List authorities = new ArrayList();
        authorities.add(new SimpleGrantedAuthority("ROLE_USER"));
        Authentication auth = new UsernamePasswordAuthenticationToken(login, pass, authorities);
        SecurityContextHolder.getContext().setAuthentication(auth);

        // IMPORTANT: Do not pass any data in the response body

        // show empty 200 page (suitable for REST clients)
        return Response.ok().build();
        // or redirect to your home page (for web UI)
        return Response.temporaryRedirect(new URI("/homepage/")).build();
    }
    else
    {
        return Response.status(Status.UNAUTHORIZED).build();
    }
}