Exception class의 ResponseStatus 사용

@ResponseStatus(value = HttpStatus.BAD_REQUEST)

 

 With {@code HttpServletResponse.sendError}, the response is considered
 complete and should not be written to any further. Furthermore, the Servlet
 container will typically write an HTML error page therefore making the
 use of a {@code reason} unsuitable for REST APIs. For such cases it is
 preferable to use a {@link org.springframework.http.ResponseEntity} as
 a return type and avoid the use of {@code @ResponseStatus} altogether.