相信大部分后端开发人员在日常开发中都需要和前端对接,当然前后端都是你自己一个人搞的话可以想怎么玩就怎么玩,但是我们还是要做到一定的规范性。在前后端分离的项目中后端返回的格式一定要友好,并且固定,不能经常变来变去,不然会对前端的开发人员带来很多的工作量。
- @PostMapping("/test")
- public String test(){
- return "Hello World";
- }
- 复制代码
postman调用结果:

- @PostMapping("/getUser")
- public ActionResult getUser(){
- User user = new User();
- user.setId(UUID.randomUUID().toString());
- user.setName("MrDong");
- user.setAge(20);
- return ActionResult.defaultOk(user);
- }
- 复制代码
postman调用结果:

- @PostMapping("/error")
- public ActionResult error(){
- return ActionResult.defaultFail(1000,"服务器异常,请联系管理员");
- }
- 复制代码
postman调用结果:

我定义两个ActionResult这个对象来对返回值进行封装,可以根据自己公司实际情况修改:
- package com.wxd.entity;
-
- import com.wxd.enums.ResultCodeEnum;
- import lombok.Data;
-
- /**
- * @ClassName ActionResult
- * @Description 统一返回值封装
- * @Author Mr Dong
- * @Date 2022/7/26 14:51
- */
- @Data
- public class ActionResult {
-
- private Integer code;
- private String msg;
- private Integer count;
- private Object data;
-
- public static ActionResult defaultOk(Integer code, String msg, Integer count, Object data) {
- return new ActionResult(code, msg, count, data);
- }
-
- public static ActionResult defaultOk(Integer count, Object data) {
- return new ActionResult(ResultCodeEnum.RC200, count, data);
- }
-
- public static ActionResult defaultOk(Object data) {
- return new ActionResult(ResultCodeEnum.RC200, null, data);
- }
-
- public static ActionResult defaultOk() {
- return new ActionResult(ResultCodeEnum.RC200);
- }
-
- public static ActionResult defaultFail() {
- return new ActionResult(ResultCodeEnum.RC999);
- }
-
- public static ActionResult defaultFail(Integer code, String msg) {
- return new ActionResult(code, msg);
- }
-
- public static ActionResult defaultFail(ResultCodeEnum resultCodeEnum) {
- return new ActionResult(resultCodeEnum);
- }
-
- public ActionResult(Integer code, String msg, Integer count, Object data) {
- this.code = code;
- this.msg = msg;
- this.count = count;
- this.data = data;
- }
-
- public ActionResult(Integer code, String msg) {
- this.code = code;
- this.msg = msg;
- }
-
- public ActionResult(ResultCodeEnum resultCodeEnum) {
- this.code = resultCodeEnum.getCode();
- this.msg = resultCodeEnum.getMessage();
- }
-
- public ActionResult(ResultCodeEnum resultCodeEnum, Integer count, Object data) {
- this.code = resultCodeEnum.getCode();
- this.msg = resultCodeEnum.getMessage();
- this.count = count;
- this.data = data;
- }
-
- }
- 复制代码
- package com.wxd.enums;
-
- /**
- * @author wxd
- * @version V1.0
- * @description ResultCodeEnum
- * @date 2022/8/10 13:35
- **/
- public enum ResultCodeEnum {
- /**
- * 操作成功
- */
- RC200(200, "操作成功"),
- /**
- * 未授权
- */
- RC401(401, "用户未授权"),
- /**
- * 请求被禁止
- */
- RC403(403, "请求被禁止"),
- /**
- * 服务异常
- */
- RC500(500, "服务器异常,请联系管理员"),
- /**
- * 操作失败
- */
- RC999(999, "操作失败"),
-
- RC1001(1001, "用户名密码错误"),
- RC1002(1002, "未授权的资源"),
- RC1003(1003, "未授权的资源"),
- RC1004(1004, "缺少请求参数异常"),
- RC1005(1005, "缺少请求体参数异常"),
- RC1006(1006, "参数绑定异常"),
- RC1007(1007, "方法参数无效异常");
-
- private Integer code;
- private String message;
-
- ResultCodeEnum(Integer code, String message) {
- this.code = code;
- this.message = message;
- }
-
- public Integer getCode() {
- return code;
- }
-
- public String getMessage() {
- return message;
- }
- }
- 复制代码
实现原理:需要实现SpringBoot提供的ResponseBodyAdvice这个接口,完成统一返回值的封装及异常的处理。实现了这个接口之后,在Controller返回的时候只需要将对象直接返回,有些不需要返回值的可以直接返回void。
- package com.wxd.advice;
-
- import com.wxd.entity.ActionResult;
- import com.wxd.enums.ResultCodeEnum;
- import lombok.extern.slf4j.Slf4j;
- import org.springframework.core.MethodParameter;
- import org.springframework.http.HttpStatus;
- import org.springframework.http.MediaType;
- import org.springframework.http.converter.HttpMessageNotReadableException;
- import org.springframework.http.server.ServerHttpRequest;
- import org.springframework.http.server.ServerHttpResponse;
- import org.springframework.validation.BindException;
- import org.springframework.web.bind.MethodArgumentNotValidException;
- import org.springframework.web.bind.MissingServletRequestParameterException;
- import org.springframework.web.bind.annotation.ExceptionHandler;
- import org.springframework.web.bind.annotation.ResponseStatus;
- import org.springframework.web.bind.annotation.RestControllerAdvice;
- import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
-
- /**
- * @version: V1.0
- * @author: wxd
- * @description: 全局异常处理以及返回值的统一封装
- * @Date 2022/7/26 16:24
- */
- @RestControllerAdvice(value = "com.wxd.controller")
- @Slf4j
- public class ResponseAdvice implements ResponseBodyAdvice {
-
- @Override
- public boolean supports(MethodParameter methodParameter, Class aClass) {
- return true;
- }
-
- /**
- * 统一包装
- *
- * @param o
- * @param methodParameter
- * @param mediaType
- * @param aClass
- * @param serverHttpRequest
- * @param serverHttpResponse
- * @return
- */
- @Override
- public Object beforeBodyWrite(Object o, MethodParameter methodParameter, MediaType mediaType, Class aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
- /**
- * String、ActionResult不需要再包一层(不想包一层ActionResult对象的可以在这里把这个对象过滤掉)
- */
- if (o instanceof String || o instanceof ActionResult) {
- return o;
- }
- return ActionResult.defaultOk(o);
- }
-
- /**
- * 系统内部异常捕获
- *
- * @param e
- * @return
- */
- @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
- @ExceptionHandler(value = Exception.class)
- public Object exceptionHandler(Exception e) {
- log.error("系统内部异常,异常信息", e);
- return ActionResult.defaultFail(ResultCodeEnum.RC500);
- }
-
-
- /**
- * 忽略参数异常处理器;触发例子:带有@RequestParam注解的参数未给参数
- *
- * @param e 忽略参数异常
- * @return ResponseResult
- */
- @ResponseStatus(HttpStatus.BAD_REQUEST)
- @ExceptionHandler(MissingServletRequestParameterException.class)
- public Object parameterMissingExceptionHandler(MissingServletRequestParameterException e) {
- log.error("缺少Servlet请求参数异常", e);
- return ActionResult.defaultFail(ResultCodeEnum.RC1004);
- }
-
- /**
- * 缺少请求体异常处理器;触发例子:不给请求体参数
- *
- * @param e 缺少请求体异常
- * @return ResponseResult
- */
- @ResponseStatus(HttpStatus.BAD_REQUEST)
- @ExceptionHandler(HttpMessageNotReadableException.class)
- public Object parameterBodyMissingExceptionHandler(HttpMessageNotReadableException e) {
- log.error("参数请求体异常", e);
- return ActionResult.defaultFail(ResultCodeEnum.RC1005);
- }
-
-
- /**
- * 统一处理请求参数绑定错误(实体对象传参);
- *
- * @param e BindException
- * @return ResponseResult
- */
- @ResponseStatus(HttpStatus.BAD_REQUEST)
- @ExceptionHandler(BindException.class)
- public Object validExceptionHandler(BindException e) {
- log.error("方法参数绑定错误(实体对象传参)", e);
- return ActionResult.defaultFail(ResultCodeEnum.RC1006);
- }
-
- /**
- * 统一处理请求参数绑定错误(实体对象请求体传参);
- *
- * @param e 参数验证异常
- * @return ResponseResult
- */
- @ResponseStatus(HttpStatus.BAD_REQUEST)
- @ExceptionHandler({MethodArgumentNotValidException.class})
- public Object parameterExceptionHandler(MethodArgumentNotValidException e) {
- log.error("方法参数无效异常(实体对象请求体传参)", e);
- return ActionResult.defaultFail(ResultCodeEnum.RC1007);
- }
-
- }
- 复制代码


