Java利用继承和抽象写发红包案例

1.定义父类

package cn.demo.extend.demo13;

public class User {
    
    
    private String name;//姓名
    private int money;//余额

    public User(){
    
    

    }

    public User(String name, int money) {
    
    
        this.name = name;
        this.money = money;
    }
    //展示一些当前用户有多少前
    public void show(){
    
    
        System.out.println("我叫："+name+",我有多少钱："+money);
    }

    public String getName() {
    
    
        return name;
    }

    public void setName(String name) {
    
    
        this.name = name;
    }

    public int getMoney() {
    
    
        return money;
    }

    public void setMoney(int money) {
    
    
        this.money = money;
    }
}

2.定义发红包的群主类

package cn.demo.extend.demo13;

import java.util.ArrayList;

//群主的类
public class Manager extends User{
    
    
    public Manager(){
    
    

    }
    public Manager(String name, int money) {
    
    
        super(name, money);
    }
    public ArrayList<Integer> send(int totalMoney,int count){
    
    
        //首先需要一个集合，用来存储若干个红包的金额
        ArrayList<Integer> redList = new ArrayList<>();

        //首先看群主的余额
        int leftMoney = super.getMoney();
        if (totalMoney > leftMoney){
    
    
            System.out.println("余额不足");
            return redList;//返回空集合
        }

        //扣钱==》重新设置余额
        super.setMoney(leftMoney - totalMoney);

        //发红包需要平均拆成count份
        int avg = totalMoney / count;
        int mod = totalMoney % count;//余数

        //除不开的零头，包在最后一个红包中
        //下面把红包一个一个放到集合中
        for (int i = 0; i < count - 1; i++) {
    
    
            redList.add(avg);
        }

        //最后一个红包
        int last = avg + mod;
        redList.add(last);

        return redList;
    }
}

3.定义普通成员类

package cn.demo.extend.demo13;

import java.util.ArrayList;
import java.util.Random;

public class Member extends User{
    
    

    public Member() {
    
    
    }

    public Member(String name, int money) {
    
    
        super(name, money);
    }

    public void receive(ArrayList<Integer> list){
    
    
        //从多个红包中随便抽取一个，给自己
        //随机获取一个集合中的索引编号
        int index = new Random().nextInt(list.size());
        //根据索引从集合中删除，并且得到被删除的红包给自己
        int delta = list.remove(index);
        //当前成员本类有多少钱
        int money = super.getMoney();
        //加法，并且重新设置回去
        super.setMoney(money + delta);
    }
}

4.定义主类

package cn.demo.extend.demo13;

import java.util.ArrayList;

public class MainRed {
    
    
    public static void main(String[] args) {
    
    
        Manager manager = new Manager("群主",100);

        Member one = new Member("成员A",0);
        Member two = new Member("成员B",0);
        Member three = new Member("成员C",0);


        manager.show();
        one.show();
        two.show();
        three.show();
        System.out.println("===============");

        //群主总共发20，3个红包
        ArrayList<Integer> redList = manager.send(20,3);
        //收红包
        one.receive(redList);
        two.receive(redList);
        three.receive(redList);

        manager.show();//我叫：群主,我有多少钱：80
        one.show();//我叫：成员A,我有多少钱：6
        two.show();//我叫：成员B,我有多少钱：6
        three.show();//我叫：成员C,我有多少钱：8
    }
}