目的：给返回对象补充一些信息，告诉前端这个请求在业务层面上是成功还是失败，以及具体的描述信息。

我们需要自定义错误码（因为前端的HTTP状态码默认的值比较少）和正常错误返回类。

ErrorCode ：

package com.heo.ezyuserbackend.common;public enum ErrorCode {SUCCESS(0, "ok", ""),PARAMS_ERROR(40000, "请求参数错误", ""),NULL_ERROR(40001, "请求参数为空", ""),NOT_LOGIN(40100, "未登录", ""),NO_AUTH(40101, "无权限", ""),SYSTEM_ERROR(50000,"系统内部异常","");private final int code;/*** 状态码信息*/private  final String message;public int getCode() {return code;}public String getMessage() {return message;}public String getDescription() {return description;}/*** 状态码描述（详情）*/private final String description;ErrorCode(int code, String message, String description) {this.code = code;this.message = message;this.description = description;}
}

BaseResponse：

package com.heo.ezyuserbackend.common;import lombok.Data;import java.io.Serializable;/*** 通用返回类** @param <T>*/
@Data
public class BaseResponse<T> implements Serializable {private int code;private T data;private String message;private String description;public BaseResponse(int code, T data, String message, String description) {this.code = code;this.data = data;this.message = message;this.description = description;}public BaseResponse(int code, T data,String message) {this(code, data, message,"");}public BaseResponse(int code, T data) {this(code, data, "", "");}public BaseResponse(ErrorCode errorCode) {this(errorCode.getCode(), null, errorCode.getMessage(), errorCode.getDescription());}
}

ResultUtil ：

package com.heo.ezyuserbackend.common;import com.fasterxml.jackson.databind.ser.Serializers;/*** 返回工具类*/
public class ResultUtil {/*** 成功** @param data* @param <T>* @return*/public static <T> BaseResponse<T> success(T data) {return new BaseResponse<>(0, data, "ok");}/*** 失败** @param errorCode* @return*/public static <T> BaseResponse<T> error(ErrorCode errorCode) {return new BaseResponse<>(errorCode);}/*** 失败** @param code* @param message* @param description* @param <T>* @return*/public static <T> BaseResponse<T> error(int code, String message, String description) {return new BaseResponse<>(code, null, message, description);}/*** 失败** @param errorCode* @param message* @param description* @param <T>* @return*/public static <T> BaseResponse<T> error(ErrorCode errorCode, String message, String description) {return new BaseResponse<>(errorCode.getCode(), null, message, description);}/*** 失败** @param errorCode* @param description* @return*/public static BaseResponse error(ErrorCode errorCode, String description) {return new BaseResponse<>(errorCode.getCode(), errorCode.getMessage(), description);}
}