意外错误（类型=未找到，状态= 404）

Question

我正在使用Spring Boot并出现错误：发生意外错误（类型=未找到，状态= 404）

我的.jsp页面位于文件夹src>main>webapp>WEB-INF>views

中

application.properties：

spring.mvc.view.prefix:/WEB-INF/views/
spring.mvc.view.suffix:.jsp
spring.messages.basename=validation

控制器：

@Controller
public class UserController {
    @Autowired
    private UserService userService;

    @Autowired
    private SecurityService securityService;

    @Autowired
    private UserValidator userValidator;

    @GetMapping("/registration")
    public String registration(Model model) {
        model.addAttribute("userForm", new User());

        return "registration";
    }

    @PostMapping("/registration")
    public String registration(@ModelAttribute("userForm") User userForm, BindingResult bindingResult) {
        userValidator.validate(userForm, bindingResult);

        if (bindingResult.hasErrors()) {
            return "registration";
        }

        userService.save(userForm);

        securityService.autoLogin(userForm.getUsername(), userForm.getPasswordConfirm());

        return "redirect:/welcome";
    }

    @GetMapping("/login")
    public String login(Model model, String error, String logout) {
        if (error != null)
            model.addAttribute("error", "Your username and password is invalid.");

        if (logout != null)
            model.addAttribute("message", "You have been logged out successfully.");

        return "login";
    }

    @GetMapping({"/", "/welcome"})
    public String welcome(Model model) {
        return "welcome";
    }
}

但是它仍然找不到页面。我该怎么办？