java - 是否可以直接从服务层抛出ResponseStatusException，而无需在 Controller 层面抛出自定义异常和处理？

Question

Spring 5 引入了 ResponseStatusException，直接从服务层抛出这个异常是不是一个好习惯。

案例1:

@Service
public class UserService {
    public User findUserByName(String username) {
       User user = userRepository.findByUsernName(username);
       if(null == user) {
          throw new ResponseStatusException(HttpStatus.NOT_FOUND, "user not found");
       }
    }
}

案例2:
还是我们需要使用自定义异常并在 Controller 级别处理它？在这种情况下，我们正在捕获 CustomException 并抛出 ResponseStatusException，为什么我们必须再次捕获自定义异常而不是使用 Case 1

@Service
public class UserService {
    public User findUserByName(String username) {
       User user = userRepository.findByUsernName(username);
       if(null == user) {
          throw new UserNotFoundException("user not found");
       }
    }
}

@RestController
public class UserController {

    @GetMapping(path="/get-user")
    public ResponseEntity<User> getUser(String username) {
      try {
         userService.findUserByName(username);
      } catch (UserNotFoundException ex) {
         throw new ResponseStatusException(HttpStatus.NOT_FOUND, "user not found");
      }
    }
}

Answer 1

正如评论中提到的，您可以在错误中创建映射。那么你不需要在 Controller 中使用 try 块。

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "user not found")
public class UserNotFoundException extends RuntimeException {

    public UserNotFoundException(String message) {

        super(message);
    }
}