1. 결정된 구조

@Component
@RequiredArgsConstructor
public class MemberResolver implements HandlerMethodArgumentResolver {

    private final OauthAccountRepository oauthAccountRepository;

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterType().equals(MemberDetails.class);
    }

    @Override
    public MemberDetails resolveArgument(
            MethodParameter parameter,
            ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest,
            WebDataBinderFactory binderFactory
    ) {
        HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);

        Long accountId = (Long) request.getAttribute("account_id");
        OauthAccount account = oauthAccountRepository.findByIdWithMember(accountId)
                .orElseThrow(() -> new CommonException(NOT_FOUND_OAUTH_ACCOUNT));

        return new MemberDetails(account.getMember().getId());
    }
}

@Component
@RequiredArgsConstructor
public class OauthAccountResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.getParameterType().equals(OauthAccountDetails.class);
    }

    @Override
    public OauthAccountDetails resolveArgument(
            MethodParameter parameter,
            ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest,
            WebDataBinderFactory binderFactory
    ) {
        HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);

        Long accountId = (Long) request.getAttribute("account_id");

        return new OauthAccountDetails(accountId);
    }
}

2. 구조 요약

🔑 토큰 정보

• OauthAccount의 id를 담음

🎯 Resolver 반환 타입

• MemberResolver → MemberDetails 반환

• OauthAccountResolver → OauthAccountDetails 반환

  → 공통적으로 DTO 반환 → 서비스 레이어에서 DB 재조회 발생

📂 Resolver의 DB 접근 방식

• OauthAccountResolver
  • DB 접근 없음
  • 토큰에 담긴 id 그대로 반환
• MemberResolver
  • DB 접근 수행
  • 토큰의 id로 OauthAccount + Member 조회 → DTO 생성

3. 고려한 대안

🅰️ MemberResolver 삭제, OauthAccountResolver만 유지

• 모든 서비스에서 OauthAccountDetails를 받고, 필요한 경우 DB 접근

✅ 이점

• Resolver 내부에서 DB 접근이 사라짐
• 단순히 id만 전달하는 lightweight 구조 가능

⚠️ 우려