Optional

회원 조회
Service

@Transactional(readOnly = true)  
public ResponseEntity findByUserId(String userId) {  
  User user = userQueryRepository.findByUserId(id)  
      .orElseThrow(() -> new CustomUserNotFoundException("등록되지 않은 아이디 " + id));

  CommonResult successResult = responseService.getSuccessResult();  
  successResult.setCode(200);  
  successResult.setMsg("아이디 등록 확인");  
  return ResponseEntity.ok().headers(responseHeaders).body(successResult);  
}

 

Repository

@Override  
public Optional findByUserId(String userId) {  
  return Optional.ofNullable(queryFactory.selectFrom(user)  
      .where(user.userId.eq(userId), user.delDate.isNull())  
      .fetchOne());  
}