[Java知识库]Java应用_模拟微信抢红包

如何用Java实现一个微信抢红包的过程呢？

Main.java

package redEnvelope;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        //红包金额和人数
        double money = 0;
        int people = 0;

        System.out.println("请输入红包的大小和人数");
        Scanner reader = new  Scanner(System.in);
        money = reader.nextDouble();
        people = reader.nextInt();
        //保证每人至少一分钱
        while((money<(people*RandomRedEnvelope.minMoney)) || (people <= 0)){
            System.out.println("输入金额或人数不支持！请重新输入红包的大小和人数：");
            money = reader.nextDouble();
            people = reader.nextInt();
        }
        //构建一个抢红包实例
        RandomRedEnvelope randomRedEnvelope = new RandomRedEnvelope(money, people);

        System.out.printf("%.2f红包已被%d个人抢完，结果如下:\n", money, people);
        showProgress(randomRedEnvelope);
    }
    public static void showProgress(RandomRedEnvelope randomRedEnvelope){
        while(randomRedEnvelope.remainPeople>0){
            double money = randomRedEnvelope.giveMoney();
            System.out.printf("%.2f\t",money);
        }
    }
}

RedEnvelope.java

package redEnvelope;

public abstract class RedEnvelope {
    public double remainMoney;      //红包当前金额
    public int remainPeople;        //抢红包的人数
    public abstract double giveMoney();     //抢红包方法
}

RandomRedEnvelope.java

package redEnvelope;
import java.util.Random;

public class RandomRedEnvelope extends RedEnvelope{     //随机红包
    double money = 0;       //最后用户得到的金额
    int randomMoney = 0; //系统随机产生的金额

    public static double minMoney = 0.01;        //设置红包最小金额为1分钱

    int integerRemainMoney;  //红包当前金额用分表示
    int integerMinMoney;     //红包最小金额用分表示

    RandomRedEnvelope(double remainMoney, int remainPeople){
        //设置红包的大小，抢的人数，每人至少抢到的金额
        this.remainMoney = remainMoney;
        this.remainPeople = remainPeople;
        integerRemainMoney = (int)remainMoney*100;
        integerMinMoney = (int)(minMoney*100);
    }

    public double giveMoney(){
        //重写抽象方法中抢红包实例
        if(remainPeople == 1){
            money = remainMoney;
            remainPeople--;
            return money;
        }
        Random random = new Random();
        randomMoney = random.nextInt(integerRemainMoney);
        //如果随机产生的钱太小，那这个红包的钱就是一分
        if(randomMoney < integerMinMoney){
            randomMoney = integerMinMoney;
        }
        //剩余用来抢的钱
        int leftOtherPeopleMoney = integerRemainMoney - randomMoney;
        //其他人至少能得到的钱
        int otherPeopleNeedNoney = integerMinMoney*(remainPeople-1);
        if(leftOtherPeopleMoney < otherPeopleNeedNoney){
            randomMoney -= (otherPeopleNeedNoney - leftOtherPeopleMoney);
        }
        integerRemainMoney -= randomMoney;
        remainMoney = (double)(integerRemainMoney/100.0);
        remainPeople--;

        money = (randomMoney/100.0);
        return money;
    }
}