Spring MVC redirect failed - spring

Question

I wanted to do a login page with Spring MVC + Mybatis, the controllers are as below:
#Controller
public class LoginController {
private final UserService userService;
#Autowired
public LoginController(#Qualifier("userService") UserService userService) {
this.userService = userService;
}
#RequestMapping(value = "/login")
public ModelAndView Login(String username, String password,
ModelAndView mv, HttpSession session) {
User user = userService.login(username, password);
// **This is where problems occured**
if (user != null) {
session.setAttribute("user", user);
mv.setView(new RedirectView("/main"));
} else {
mv.addObject("message","Login failed.");
mv.setViewName("loginForm");
}
return mv; // with correct value, but responses 404 error
}
#RequestMapping(value = "/loginForm")
public String LoginForm() {
return "loginForm";
}
#RequestMapping(value = "/main")
public String Main(Model model) {
return "main";
}
}
I have two jsp files:
/WEB-INF/jsp/loginForm.jsp
/WEB-INF/jsp/main.jsp
Whether I submit the login form correctly or not, there is a 404 error:
HTTP Status 404 - /WEB-INF/jsp/login.jsp
Running in debug mode, the mv was returned with "/main" correctly, so it confused me.
Code below works, but i cant add error message to view anymore.
#RequestMapping(value = "/login")
public String Login(String username, String password, HttpSession session) {
User user = userService.login(username, password);
if (user != null) {
session.setAttribute("user", user);
return "redirect:/main";
} else {
session.setAttribute("message","Login failed");
return "redirect:/loginForm";
}
}

Answer 1

i have face same issue but it's help for me
ModelAndView model = new ModelAndView();
if (user != null) {
session.setAttribute("user", user);
model = new ModelAndView("/main");
} else {
mv.addObject("message","Login failed.");
model = new ModelAndView("/loginForm");
}
return model;