@ModelAttribute formed model cannot be used in another Controller

Question

My UserController.java

@Controller
@RequestMapping("/userRegistration")
public class UserController{

    @RequestMapping(method = RequestMethod.GET)
    public String showForm(ModelMap model) {
        User user = new User();
        model.addAttribute(user);
        return "userForm";
    }

@RequestMapping(method = RequestMethod.POST)
public String onFormSubmit(@ModelAttribute("user") User user) {   // **#1**
    return "redirect:userSuccess.htm";                // **#2**
    }

}

My SuccessController.java

@Controller
public class SuccessController {

    @RequestMapping("/userSuccess.htm")
    public String getSuccessPage(@ModelAttribute("user") User user){       // **#3**
        return "userSuccess";
    }
}

I am not getting "user" model in SuccessController and so when I use ${user.name} in userSuccess.jsp, I don't get any value.

When I set user model at Line 1, why don't I get this value in another controller? If I keep this model in Session using @SessionAttributes, I can access it in another controller.

Then what is the scope of models formed using @ModelAttribute?

Answer 1

It's in the request, unless modified with a @SessionAttributes as described here. (Delta the other cases described here.) You're doing a redirect--request attributes are lost; it's a new request.

You answered your own question in your text: when you keep it in session, it's available across controllers and redirects, because it's in the session. If you don't keep it in session, it's not.