Spring multiple @ModelAttribute methods in the same @Controller

Question

I have a page with two different forms (with two different submits) on Spring MVC 3, and I have a problem with @ModelAttribute methods. When I have two on the same controller, they are not always executed making the model to be NULL.

The code:

@Controller
@RequestMapping(value = "/session/admin/permission/{userId}")
public class PermissionController {

    @Autowired
    private UserManager userManager;

    @ModelAttribute("passwordValidation")
    private PasswordValidation getPasswordModel(){
        return new PasswordValidation();
    }

    @ModelAttribute("user")
    private User getUserModel(@PathVariable("userId") String userId){
        //This is not executed
        return userManager.getUser(userId);
    }

    @ModelAttribute("permissionsAvailable")
    private PermissionsAvailable getPermissionsModel(@ModelAttribute("user") User user)     {
        return new PermissionsAvailable();
    }

    @RequestMapping(method = RequestMethod.GET)
    public String adminPermission(){
        return "/security/permission";
    }

    @RequestMapping(method = RequestMethod.POST, params="changeRoles")
    public String modifyPermission(@ModelAttribute("permissionsAvailable") PermissionsAvailable permissions,
            HttpServletRequest request, @ModelAttribute("user") User user, 
            final RedirectAttributes redirectAttributes){
        //Modify something
    }

    @RequestMapping(method = RequestMethod.POST, params="changePassword")
    public String modifyPassword(
            @ModelAttribute("passwordValidation") PasswordValidation passwordValidation,
            @ModelAttribute("user") User user,
            HttpServletRequest request, BindingResult bindingResult, 
            final RedirectAttributes redirectAttributes){
        return "newpage";
    }
}

Don't know why, sometimes everything goes ok and every method is executed, but sometimes they are not executed.

UPDATE: I have two different controllers with the same problem so it must be an error on Spring or something I'm doing wrong.

Thanks.

Solution

The documentation doesn't mention anywhere that it's possible to use @ModelAttribute on an argument to a @ModelAttribute annotated method, like you're doing in your "getPermissionsModel()" method. It's possible that's not supported, since it's not documented as being supported. You might want to try either removing the "@ModelAttribute("user") User user" argument from your "getPermissionsModel()" method, and/or instead try just using one @ModelAttribute method to set all your model attributes:

@ModelAttribute
public void setAttributes(@PathVariable("userId") String userId, Model model) {
    model.addAttribute(new PasswordValidation());
    model.addAttribute(userManager.getUser(userId));
    model.addAttribute(new PermissionsAvailable());
}

Comments

[droidpl]

Yeh that works! It seems that you ae right it is not supported!