SpringBoot统一返回值处理及异常处理

客官°小女子只卖身不卖艺 2022-02-15 10:18 491阅读 0赞

先整体看下代码结构：  
![在这里插入图片描述][20190424121149951.png]  
返回结果封装类RestResult：

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class RestResult {
    
        private Integer code;
        private String message;
        private Object data;
    
        public static RestResult of(Object data) {
            return new RestResult(0, "success", data);
        }
    
        public static RestResult of(Exception e) {
            if (e instanceof BusinessException) {
                return new RestResult(((BusinessException) e).getCodeId(), e.getMessage(), ((BusinessException) e).getErrors());
            } else {
                return new RestResult(500, e.getMessage(), Collections.emptyMap());
            }
        }
    
        public static RestResult of(Exception e, Integer code) {
            if (e instanceof BusinessException) {
                return new RestResult(((BusinessException) e).getCodeId(), e.getMessage(), ((BusinessException) e).getErrors());
            } else {
                return new RestResult(code, e.getMessage(), Collections.emptyMap());
            }
        }
    }

统一异常封装类：

/**
     * @description: 对于需要给用户展示的异常，统一抛出此异常
     * @author: JJC
     * @createTime: 2019/3/28
     */
    public class BusinessException extends RuntimeException implements Serializable {
        private final ErrorCode code;
        private final Map<String, ? extends Object> errors;
    
        public BusinessException(ErrorCode code, Map<String, Object> errors) {
            super(code.getReason());
            this.code = code;
            this.errors = errors;
        }
    
        public BusinessException(String message, ErrorCode code, Map<String, ? extends Object> errors) {
            super(message);
            this.code = code;
            this.errors = errors;
        }
    
        public BusinessException(String message, Throwable cause, ErrorCode code, Map<String, ? extends Object> errors) {
            super(message, cause);
            this.code = code;
            this.errors = errors;
        }
    
        public BusinessException(Throwable cause, ErrorCode code, Map<String, ? extends Object> errors) {
            super(cause.getMessage(), cause);
            this.code = code;
            this.errors = errors;
        }
    
        public BusinessException(ErrorCode code) {
            super(code.getReason());
            this.code = code;
            this.errors = new HashMap<>();
        }
    
        public BusinessException(String message, ErrorCode code) {
            super(message);
            this.code = code;
            this.errors = new HashMap<>();
        }
    
        public BusinessException(String message, Throwable cause, ErrorCode code) {
            super(message, cause);
            this.code = code;
            this.errors = cause instanceof ServiceException ? ((ServiceException) cause).getErrors() : new HashMap<>();
        }
    
        public BusinessException(Throwable cause, ErrorCode code) {
            super(cause.getMessage(), cause);
            this.code = code;
            this.errors = cause instanceof ServiceException ? ((ServiceException) cause).getErrors() : new HashMap<>();
        }
    
        public ErrorCode getCode() {
            return this.code;
        }
    
        @Override
        public String toString() {
            Map<String, Object> map = new HashMap<>();
            map.put("httpStatus", this.getCode().getHttpStatus());
            map.put("code", this.getCode().getCode());
            map.put("reason", this.getCode().getReason());
            map.put("solution", this.getCode().getSolution());
            map.put("message", this.getMessage());
            return JSONObject.toJSONString(map, SerializerFeature.WriteMapNullValue);
        }
    
        public Map<String, ? extends Object> getErrors() {
            return this.errors;
        }
    
        public Integer getCodeId() {
            return this.code.getCode();
        }
    }

异常枚举：

@Getter
    public enum ErrorCode {
    
        // 通用
        METHOD_ARGUMENT_NOT_VALID(HttpStatus.BAD_REQUEST.value(),HttpStatus.BAD_REQUEST.value(),"参数约束错误","调整参数");
    
        private Integer httpStatus;
        private Integer code;
        private String reason;
        private String solution;
    
        ErrorCode(Integer httpStatus, Integer code, String reason, String solution) {
            // FIXME: 自定义异常的 Http Status 统一为 200
            this.httpStatus = HttpStatus.OK.value();
            // 错误码的前缀为期望的HttpStatus
            this.code = code;
            this.reason = reason;
            this.solution = solution;
        }
    }

统一返回值处理：

@ControllerAdvice(annotations = RestController.class)
    public class ResultHandlerAdvice implements ResponseBodyAdvice<Object> {
    
        @Override
        public boolean supports(MethodParameter returnType, Class converterType) {
            return true;
        }
    
        @Override
        public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType mediaType, Class converterType, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
            if (null == body) {
                return RestResult.of(Collections.emptyMap());
            }
            return RestResult.of(body);
        }
    
    }

统一异常处理：

@ControllerAdvice(annotations = RestController.class)
    public class PandaExceptionHandler extends ResponseEntityExceptionHandler {
        private static Logger logger = LoggerFactory.getLogger(PandaExceptionHandler.class);
    
        /**
         * 处理业务异常
         */
        @ExceptionHandler(value = Exception.class)
        protected ResponseEntity<Object> handleException(Exception exception, HttpServletRequest request, HttpServletResponse response) {
            this.logError(exception, request.getRequestURI(), request.getParameterMap());
            RestResult errorBody = RestResult.of(exception);
            ResponseEntity<Object> responseEntity = new ResponseEntity<>(errorBody, HttpStatus.INTERNAL_SERVER_ERROR);
            return responseEntity;
        }
    
        private void logError(Exception exception, String uri, Map<String, String[]> parameterMap) {
            logger.error("request error.request url:" + uri + ". params:" + JSONObject.toJSON(parameterMap).toString() + ". traceId:" + Tracer.id());
            logger.error(exception.toString(), exception);
        }
    
        @Override
        protected ResponseEntity<Object> handleExceptionInternal(Exception exception, @Nullable Object body, HttpHeaders headers, HttpStatus status, WebRequest request) {
            this.logError(exception, ((ServletWebRequest) request).getRequest().getRequestURI(), request.getParameterMap());
            if (HttpStatus.INTERNAL_SERVER_ERROR.equals(status)) {
                request.setAttribute("javax.servlet.error.exception", exception, 0);
            }
            RestResult errorBody = RestResult.of(exception, status.value());
            return new ResponseEntity(errorBody, headers, status);
        }
    
        /**
         * 处理javax.validation参数校验不通过异常
         */
        @Override
        protected ResponseEntity<Object> handleMethodArgumentNotValid(
            MethodArgumentNotValidException exception, HttpHeaders headers, HttpStatus status, WebRequest request) {
            Map<String, Object> errors = new HashMap<>();
            for (ObjectError error : exception.getBindingResult().getAllErrors()) {
                errors.put(((FieldError) error).getField(), error.getDefaultMessage());
            }
            BusinessException businessException = new BusinessException(ErrorCode.METHOD_ARGUMENT_NOT_VALID, errors);
            return this.handleException(businessException, RequestContextHolderUtil.getRequest(), RequestContextHolderUtil.getResponse());
        }
    }

有个坑需要注意，因为统一对@RestController进行了拦截，因此对于健康检查等返回String的Controller会抛异常，因此对于健康检查等返回String的Controller使用@Controller与@ResponseBody代替@RestController即可

[20190424121149951.png]: /images/20220215/0ed567a74f0b42949317809c2531abf9.png