package com.deng.hongbao.base;
/**
 * 先構建一個格式確定下來的Result類
 * 然後構建一個常用的列舉類，內容可以根據專案自定義,檢視ResultEnum
 * 然後就是寫一個返回的工具類ResultUtil
 * 最後就是應用了，在Controller裡邊呼叫ResultUtil就可以了
 *
 * 還要考慮拋異常情況,就是當條件滿足時,直接把資訊拋給瀏覽器,比如未滿18歲,返回瀏覽器"未成年"
 * 建立一個handle包,建立一個ExceptionHandle類(或者XXServiceException類)
 *再建立一myException包,建立一個serviceException類繼承RuntimeException類
 

 * */

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 {
    //這裡是可以自己定義的，方便與前端互動即可
    UNKNOWN_ERROR(-1,"未知錯誤"),
    SUCCESS(0,"成功"),
    USER_NOT_EXIST(1,"使用者不存在"),
    USER_IS_EXISTS(2,"使用者已存在"),
    DATA_IS_NULL(3,"資料為空"),
    DENG_1(999,"傳送人為空1111"),// 測試
    ;
    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 {
    /**成功且帶資料**/
    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;
    }
    /**成功但不帶資料**/
    public static Result success(){

        return success(null);
    }
    /**失敗**/
    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)//對哪個異常類進行捕獲
    @ResponseBody
    public Result handle(Exception e) {

        if (e instanceof ServiceException) {
            ServiceException serviceException = (ServiceException) e;
            return ResultUtil.error(serviceException.getCode(), serviceException.getMessage());
        } else {
            // 如果是系統異常或其它異常,記錄在日誌
            logger.error("[系統異常] {}", e);
            return ResultUtil.error(-1, "未知錯誤!");
        }
    }

    // 成功用ResultUtil丟擲異常,但問題來了,這個異常類Exception,不能自定義ResultUtil的code,所以要自定義一個Exception
}

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

package com.deng.hongbao.MyException;

import com.deng.hongbao.base.ResultEnum;

public class ServiceException extends RuntimeException {

    // 繼承RuntimeException異常可以事物回滾,Exception只負責丟擲,但不回滾事物

    private Integer code;

    public ServiceException(Integer code, String msg) {
        super(msg);// 由於RuntimeException繼承了Exception,本身會有個msg檔案,所以直接呼叫
        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;
    }
}