1 package Demo511;
 2 
 3 import java.util.ArrayList;
 4 
 5 public class DemoSend {
 6     public static void main(String[] args) {
 7         Manager manager =new Manager("群主",1000);
 8         Member one =   new Member("成員A",0);
 9         Member two =   new Member("成員B",0);
10         Member three = new
 
 Member("成員C",0);
11         Member four =  new Member("成員D",0);
12         Member five =  new Member("成員E",0);
13 
14         ArrayList<Integer> redlist =manager.send(666,5);
15 
16         one.receive(redlist);
17         two.receive(redlist);
18         three.receive(redlist);
19         four.receive(redlist);
 
20         five.receive(redlist);
21 
22         manager.show();
23         one.show();
24         two.show();
25         three.show();
26         four.show();
27         five.show();
28     }
29 }

??是成員類，群主繼承成員，群員繼承成員

 1 package Demo511;
 2 
 3 public class User {
 4     private String name ;
 
 5     private int money;
 6 
 7     public User(){
 8 
 9     }
10 
11     public User(String name,int money) {
12         this.money=money;
13         this.name = name;
14     }
15     //展示一下，當前用戶的錢
16     public void show(){
17         System.out.println("我叫："+name+",還有"+money+"塊錢");
18     }
19     public String getName(){
20         return name;
21     }
22     public void setName(String name){
23         this.name=name;
24     }
25     public int getMoney(){
26         return money;
27     }
28     public void setMoney(int money){
29         this.money=money;
30     }
31 }

 1 package Demo511;
 2 
 3 import java.util.ArrayList;
 4 /*
 5 默認構造，有參構造
 6  */
 7 public class Manager extends User{
 8         public Manager(){
 9         }
10     public Manager(String name, int money) {
11         super(name, money);
12     }
13     public ArrayList<Integer> send(int totalMoney,int count) {
14             //用一個集合，來存儲若幹個紅包的金額
15         ArrayList<Integer> redList = new ArrayList<>();
16                     //查看群主的金錢余額
17         int leftMoney =super.getMoney();//群主當前余額
18         if (totalMoney>leftMoney){
19             System.out.println("余額不足");
20             return  redList;  //返回空集合
21         }
22         //扣錢就是重新設置余額
23         super.setMoney(leftMoney-totalMoney);
24          //發紅包需要評分count份
25         int avg =totalMoney/count;
26         int mod =totalMoney%count;
27         //除不開的金錢，放到最後一個紅包裏面
28         for (int i = 0; i < count-1; i++) {
29             redList.add(avg);
30         }
31         redList.add(avg+mod);
32         return  redList;
33     }
34 }

 1 package Demo511;
 2 
 3 import java.util.ArrayList;
 4 import java.util.Random;
 5 
 6 public class Member extends User {
 7     public Member() {
 8     }
 9     public Member(String name, int money) {
10         super(name, money);
11     }
12     public void receive(ArrayList<Integer>list){
13         //從多個紅包當中抽取一個給我。
14         //隨機獲取一個集合的索引編號。
15         int index =new Random().nextInt(list.size());
16         //刪除一個隨機紅包，並且給我。
17         int detal = list.remove(index);
18         int money = super.getMoney();
19         super.setMoney(money+detal);
20     }
21 }

代碼運行??

JAVA 實現簡單的發紅包案例