web 开发后端代码优化

通用返回类

作为所有请求的返回值类型

给要返回的数据补充一些信息，告诉前端这个请求在业务层面上是成功还是失败

{"code": 40000,"data": null,"message": "","description": ""
}

import lombok.Data;
import java.io.Serializable;
/*** 通用返回类** @param <T>* @author longlong*/
@Data
public class BaseResponse<T> implements Serializable {private static final long serialVersionUID = -3546852185606973846L;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.getDescrition());}
}

返回工具类

对要返回的数据进行处理

/*** 返回工具类** @author longlong*/
public class ResultUtils {/*** 成功* @param data* @return* @param <T>*/public static<T> BaseResponse<T> success(T data){return new BaseResponse<T>(0,data,"ok");}/*** 失败* @param errorCode* @return*/public static BaseResponse error(ErrorCode errorCode){return new BaseResponse(errorCode);}/*** 失败 自定义description* @param errorCode* @return*/public static BaseResponse error(ErrorCode errorCode,String description){return new BaseResponse(errorCode.getCode(),null, errorCode.getMessage(),description);}public static BaseResponse error(int code,String message,String description){return new BaseResponse(code,null, message,description);}/*** 失败 自定义message 和 description* @param errorCode* @return*/public static BaseResponse error(ErrorCode errorCode,String message, String description){return new BaseResponse(errorCode.getCode(),null, message,description);}
}

自定义错误码

/*** 错误码** @author longlong*/
public enum ErrorCode {PARAMS_ERROR(40000,"请求参数错误",""),NULL_ERROR(40001,"请求数据为空",""),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;/*** 状态码描述 详情*/private final String descrition;ErrorCode(int code, String message, String descrition) {this.code = code;this.message = message;this.descrition = descrition;}public int getCode() {return code;}public String getMessage() {return message;}public String getDescrition() {return descrition;}

自定义异常

/*** 自定义异常类** @author longlong*/
public class BusinessException extends RuntimeException{private final int code;private final String description;public BusinessException(String message, int code,String description){super(message);this.code = code;this.description = description;}public BusinessException(ErrorCode errorCode){super(errorCode.getMessage());this.code = errorCode.getCode();this.description = errorCode.getDescrition();}public BusinessException(ErrorCode errorCode,String description){super(errorCode.getMessage());this.code = errorCode.getCode();this.description = description;}public int getCode() {return code;}public String getDescription() {return description;}
}

全局异常处理

作用：

• 捕获代码中所有的异常，内部消化，让前端得到更详细的业务报错 / 信息
• 同时屏蔽掉项目框架本身的异常（不暴露服务器内部状态）
• 集中处理，比如记录日志

实现：

• Spring AOP：在调用方法前后进行额外的处理

@RestControllerAdvice
@Slf4j
public class GlobalExceptionHandler {@ExceptionHandler(BusinessException.class)public BaseResponse businessExceptionHandler(BusinessException e){log.error("businessException: "+e.getMessage()+"-"+e.getDescription(),e);return ResultUtils.error(e.getCode(),e.getMessage(),e.getDescription());}@ExceptionHandler(RuntimeException.class)public BaseResponse runtimeExceptionHandler(RuntimeException e){log.error("runtimeException: ",e);return ResultUtils.error(ErrorCode.SYSTEM_ERROR);}
}