Migration from spring mvc exception handling

[aisensiy]

I'm migrating a demo project from rest to graphql and in the spring mvc part, the customized error is using exception handler. The error content can be seperated by status code (500 internal, 400 bad request) to make it a user level error or a server side error.

According to the error handling docs two types of errors is given: Comprehensive Errors and Errors as Data.The Comprehensive Errors part is similar with the SpringMVC's exception handling flow. The Errors as Data part seems try to make a validation instead of exception handling flow which force to have a lot of try-catch to handle this:

@Service
@Validated
public class UserService {
  ...

  public User createUser(@Valid RegisterParam registerParam) {
    User user =
        new User(
            registerParam.getEmail(),
            registerParam.getUsername(),
            encryptService.encrypt(registerParam.getPassword()),
            "",
            defaultImage);
    userRepository.save(user);
    return user;
  }

  ...
}

@DgsComponent
public class UserMutation {

  private UserService userService;

  @DgsData(parentType = MUTATION.TYPE_NAME, field = MUTATION.CreateUser)
  public DataFetcherResult<UserResult> createUser(@InputArgument("input") CreateUserInput input) {
    RegisterParam registerParam =
        new RegisterParam(input.getEmail(), input.getUsername(), input.getPassword());
    User user;
    try {
      user = userService.createUser(registerParam);
    } catch (ConstraintViolationException cve) {
      return DataFetcherResult.<UserResult>newResult().data(GraphQLCustomizeExceptionHandler.getErrorsAsData(cve)).build();
    }

    return DataFetcherResult.<UserResult>newResult()
        .data(UserPayload.newBuilder().build())
        .localContext(user)
        .build();
  }

}

This looks not that elegant to me. Is there some better way to handle the Errors as Data part? The current code is gothinkster/spring-boot-realworld-example-app@472d886 hope this give a more clear description.