Overloading a spring controller method with the same request mapping

Question

I have a session attribute : user, and I have a url that I want to be viewed by both logged in users and publically by people not logged in as a user.

So what I want to do is this :

@Controller("myController")
@SessionAttributes({"user"})
public class MyController {

@RequestMapping(value = "/MyPage/{id}", method = RequestMethod.GET)
public ModelAndView getPage(@PathVariable Integer id) {
   return modelandview1;
}

@RequestMapping(value = "/MyPage/{id}", method = RequestMethod.GET)
public ModelAndView getPage(@PathVariable Integer id, @ModelAttribute User user){
  return modelandview2;
}

However, I have a feeling its not going to work ... suggestions very welcome.

Answer 1

You only need the second method, the one that takes the User agument as well. When it's called without request attributes available to populate the User model, you'll just get a User instance with all null (or all default) field values, then in the body of the method you treat each situation accordingly

Answer 2

I don't think it's a right case for @SessionAttributes. This annotation is usually used to keep original instance of a form-backing object, to avoid passing irrelevant parts of its state via hidden form fields.

Your sceanrio is completely different, thus it would be better to use HttpSession explicitly:

@RequestMapping(value = "/MyPage/{id}", method = RequestMethod.GET)
public ModelAndView getPage(@PathVariable Integer id, HttpSession session) {
    User user = (User) session.getAttribute(...);
    if (user != null) {
        ...
    } else {
        ...
    }
}

Also note that @ModelAttribute is a subject to data binding - user can change its fields by passing request parameters. You definitely don't want it in this case.