Pass parameter to controller

Question

I have some app with JWT authentication. And currently, I have such controller:

@RestController
@RequestMapping("users")
public class UserController {
    @PostMapping(value = "{userId}/rate/inc")
    public Double incRate(@PathVariable Long userId) {
        return service.incUserRate(userId);
    }
}

But, I want to get user by the token in the filter and pass it as a method's param. For example:

@PostMapping(value = "/rate/inc")
public Double incRate(User user) {
    returnservice.incUserRate(user);
}

Is this possible?

Answer 1

Implement argument resolver and inject into your controller everything you need.

By default Spring allowes you to inject Principal object that by default contains users email (it is default realization in Spring Security). But you can implement injection of your business login users account by implementing Interface HandlerMethodArgumentResolver<User>.

I advice you to create an annotation like @AuthorizedUser in make mark your User param with this annotation. And according to this annotation presence in controller method, inject your user via HandlerMethodArgumentResolver.

@Component
public class UserArgumentHandlerResovler implements HandlerMethodArgumentResolver {

    @Autowired
    private UserRepository userRepository;

    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.isAnnotationPresent(AuthorizedUser.class);
    }

    public Object   resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) { 
         Authentication auth = SecurityContextHolder.getContext().getAuthentication();
         String email = (String) auth.getPrincipal(); // <- it is a pseudocode, check your Authentication implementation to get email for example.
         return userRepository.findByEmail(email);
    }
}