一文教你处理SpringBoot统一返回格式
背景
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。
SpringBoot Controller 常见的返回格式
String
@PostMapping("/test")
public String test(){
return "Hello World";
}
复制代码postman调用结果：
自定义对象
正常返回
@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：
错误返回
@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：
定义返回对象
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;
}
}
复制代码定义状态枚举
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;
}
}
复制代码统一处理返回值及异常
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void 无返回值
有返回值
