Result类,公共返回类创建

Posted 2020-12-18 aqihao

package com.deng.hongbao.base;
/**
 * 先构建一个格式确定下来的Result类
 * 然后构建一个常用的枚举类，内容可以根据项目自定义,查看ResultEnum
 * 然后就是写一个返回的工具类ResultUtil
 * 最后就是应用了，在Controller里边调用ResultUtil就可以了
 *
 * 还要考虑抛异常情况,就是当条件满足时,直接把信息抛给浏览器,比如未满18岁,返回浏览器"未成年"
 * 建立一个handle包,建立一个ExceptionHandle类(或者XXServiceException类)
 *再建立一myException包,建立一个serviceException类继承RuntimeException类

 * */

public class Result<T> {
    private Integer code;
    private String msg;
    private T data;

    public Result() {
        super();
    }

    public Result(Integer code, String msg, T data) {
        this.code = code;
        this.msg = msg;
        this.data = data;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

    @Override
    public String toString() {
        return "Result{" +
                "code=" + code +
                ", msg=‘" + msg + ‘‘‘ +
                ", data=" + data +
                ‘}‘;
    }
}

//------------------------------------

package com.deng.hongbao.base;

public enum ResultEnum {
    //这里是可以自己定义的，方便与前端交互即可
    UNKNOWN_ERROR(-1,"未知错误"),
    SUCCESS(0,"成功"),
    USER_NOT_EXIST(1,"用户不存在"),
    USER_IS_EXISTS(2,"用户已存在"),
    DATA_IS_NULL(3,"数据为空"),
    DENG_1(999,"发送人为空1111"),// 测试
    ;
    private Integer code;
    private String msg;

    
    ResultEnum(Integer code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public Integer getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

//-------------------------------------

package com.deng.hongbao.util;

import com.deng.hongbao.base.Result;
import com.deng.hongbao.base.ResultEnum;

public class ResultUtil {
    /**成功且带数据**/
    public static Result success(Object object){
        Result result = new Result();
        result.setCode(ResultEnum.SUCCESS.getCode());
        result.setMsg(ResultEnum.SUCCESS.getMsg());
        result.setData(object);
        return result;
    }
    /**成功但不带数据**/
    public static Result success(){

        return success(null);
    }
    /**失败**/
    public static Result error(Integer code,String msg){
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        return result;
    }
}

//----------------------------------------------------------------

package com.deng.hongbao.handle;

import com.deng.hongbao.MyException.ServiceException;
import com.deng.hongbao.base.Result;
import com.deng.hongbao.util.ResultUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

@ControllerAdvice
public class ExceptionHandle {
    private final static Logger logger = LoggerFactory.getLogger(ExceptionHandle.class);

    @ExceptionHandler(value = Exception.class)//对哪个异常类进行捕获
    @ResponseBody
    public Result handle(Exception e) {

        if (e instanceof ServiceException) {
            ServiceException serviceException = (ServiceException) e;
            return ResultUtil.error(serviceException.getCode(), serviceException.getMessage());
        } else {
            // 如果是系统异常或其它异常,记录在日志
            logger.error("[系统异常] {}", e);
            return ResultUtil.error(-1, "未知错误!");
        }
    }

    // 成功用ResultUtil抛出异常,但问题来了,这个异常类Exception,不能自定义ResultUtil的code,所以要自定义一个Exception
}

// ----------------------------------------------------------

package com.deng.hongbao.MyException;

import com.deng.hongbao.base.ResultEnum;

public class ServiceException extends RuntimeException {

    // 继承RuntimeException异常可以事物回滚,Exception只负责抛出,但不回滚事物

    private Integer code;

    public ServiceException(Integer code, String msg) {
        super(msg);// 由于RuntimeException继承了Exception,本身会有个msg文件,所以直接调用
        this.code = code;
    }

    public ServiceException(ResultEnum resultEnum) {
        super(resultEnum.getMsg());
        this.code = resultEnum.getCode();
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }
}