一文教你处理SpringBoot统一返回格式

Dear 丶 2023-10-01 23:30 100阅读 0赞

## 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：

![format_png][]

### 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：

![format_png 1][]

#### 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：

![format_png 2][]

## 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;
        }
    
    }
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## 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;
        }
    }
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## 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);
        }
    
    }
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### void 无返回值 ###

![format_png 3][]

### 有返回值 ###

![format_png 4][]

![2c062f4737c34b0bba55b7fcfcf215a0.jpeg][]

[format_png]: https://img-blog.csdnimg.cn/img_convert/c3ff55cbbe6c2ae6943fc013e5ddc929.webp?x-oss-process=image/format,png
[format_png 1]: https://img-blog.csdnimg.cn/img_convert/9d118e4f56b3fcae7edee21cbd1c43eb.webp?x-oss-process=image/format,png
[format_png 2]: https://img-blog.csdnimg.cn/img_convert/64bb033878b04c3c60b33f9cf4f85bc9.webp?x-oss-process=image/format,png
[format_png 3]: https://img-blog.csdnimg.cn/img_convert/91a6ce60e2171f219f792946968a1d6f.webp?x-oss-process=image/format,png
[format_png 4]: https://img-blog.csdnimg.cn/img_convert/c685d845a17c88c2360d0c13d1e6521c.webp?x-oss-process=image/format,png
[2c062f4737c34b0bba55b7fcfcf215a0.jpeg]: https://img-blog.csdnimg.cn/2c062f4737c34b0bba55b7fcfcf215a0.jpeg