[Spring] 예외 처리

스프링 예외처리

@ControllerAdvice

@ControllerAdvice
@Log4j2
public class CommonExceptionAdvice {

    @ResponseBody
    @ExceptionHandler(NumberFormatException.class)
    public String exceptNumber(NumberFormatException numberFormatException) {

        log.error("Number------------------------------");
        log.error(numberFormatException.getMessage());

        return "NUMBER FORMAT EXCEPTION";
    }

    @ResponseBody
    @ExceptionHandler(Exception.class)
    public String exceptCommon(Exception exception) {
        log.error("common------------------------------");
        log.error(exception.getMessage());

        StringBuffer buffer = new StringBuffer("<ul");

        buffer.append("<li>" + exception.getMessage()+"</li>");

        Arrays.stream(exception.getStackTrace()).forEach(stackTraceElement -> {
            buffer.append("<li>" + stackTraceElement+"</li>");
        });
        buffer.append("</ul>");

        return buffer.toString();
    }

    @ExceptionHandler(NoHandlerFoundException.class)
    @ResponseStatus(HttpStatus.NOT_FOUND)
    public String notFound() {
        return "custom404";
    }
}

• BindException 처리
  1. Controller 파라미터에 @Valid 이 있을경우 BindException 을 throw 함
  2. @ControllerAdvice 에서 BindException 을 처리

@PostMapping(value = "/", consumes = MediaType.APPLICATION_JSON_VALUE)
    public ResponseEntity<Map<String,Long>> register(@Valid @RequestBody ReplyDTO replyDTO, BindingResult bindingResult)
            throws BindException {

        if(bindingResult.hasErrors()){
            throw new BindException(bindingResult);
        }

        log.info(replyDTO);
        Map<String, Long> resultMap = Map.of("rno", 111L);

        return ResponseEntity.ok(resultMap);
    }

@RestControllerAdvice
@Log4j2
public class CustomRestAdvice {

    @ExceptionHandler(BindException.class)
    @ResponseStatus(HttpStatus.EXPECTATION_FAILED)
    public ResponseEntity<Map<String, String>> handleBindException(BindException e) {

        log.error(e);

        Map<String, String> errorMap = new HashMap<>();

        if(e.hasErrors()){
            BindingResult bindingResult = e.getBindingResult();

            bindingResult.getFieldErrors().forEach(fieldError -> {
                errorMap.put(fieldError.getField(), fieldError.getCode());
            });
        }

        return ResponseEntity.badRequest().body(errorMap);
    }
}