微信点餐之工具类（2）

一、订单号生成类

com\imooc\utils\KeyUtil.java

package com.imooc.utils;
import java.util.Random;

/**
 * @author: menghaibin
 * @create: 2020-02-10 22:38
 * @description: 订单号生成
 **/
public class KeyUtil {

    /*
    * 生成唯一的主键
    * 格式：时间+随机数
    * */
    public synchronized static String genUniqueKey(){
        Random random = new Random();
        /*生成六位随机数*/
        Integer number = random.nextInt(900000)+100000;

        return System.currentTimeMillis()+String.valueOf(number);
    }
}

二、Json转换类

com\imooc\utils\JsonUtil.java

package com.imooc.utils;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

/**
 * @author: menghaibin
 * @create: 2020-02-23 14:24
 * @description: json格式化工具
 **/
public class JsonUtil {

    public static String toJson(Object object){
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder.setPrettyPrinting();
        Gson gson = gsonBuilder.create();
        return gson.toJson(object);
    }
}

三、支付金额校验类

com\imooc\utils\MathUtil.java

package com.imooc.utils;

/**
 * @author: menghaibin
 * @create: 2020-02-23 18:58
 * @description: 微信支付金额校验是否一致
 **/
public class MathUtil {

    private static final Double MONEY_RANGE=0.01;

    public static Boolean equals(Double d1,Double d2){
        Double result = Math.abs(d1 - d2);
        if(result < MONEY_RANGE){
            return true;
        }else{
            return false;
        }
    }
}

四、cookie操作类

package com.imooc.utils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;

/**
 * @author: menghaibin
 * @create: 2020-02-26 21:37
 * @description: 登录设置cookie
 **/
public class CookieUtil {

    /*设置cookie*/
    public static void setCookie(HttpServletResponse response,
                                 String name,String value,int maxAge){
        Cookie cookie = new Cookie(name,value);
        cookie.setPath("/");
        cookie.setMaxAge(maxAge);
        response.addCookie(cookie);

    }

    /*获取cookie*/
    public static Cookie getCookie(HttpServletRequest request,String name){
        
         Map<String,Cookie> cookieMap = readCookieMap(request);
         //判断这个map里面有没有name值
         if(cookieMap.containsKey(name)){
             return cookieMap.get(name);
         }
         return null;

    };
    
    /*被getCookie调用*/
    private static Map<String,Cookie> readCookieMap(HttpServletRequest request){
        Map<String,Cookie> cookieMap = new HashMap<>();
        Cookie[] cookies = request.getCookies();
        if(cookies !=null){
            for (Cookie cookie : cookies) {
                cookieMap.put(cookie.getName(),cookie);
            }
        }
        return cookieMap;
    }
}