查找会员积分

 1 package homework20191126;
 2 
 3 public class User {
 4 
 5     private String id;
 6     private int num;
 7     
 8     @Override
 9     public int hashCode() {
10         final int prime = 31;
11         int result = 1;
12         result = prime * result + ((id == null) ? 0 : id.hashCode());
13         return result;
14     }
15     @Override
16     public boolean equals(Object obj) {
17         if (this == obj)
18             return true;
19         if (obj == null)
20             return false;
21         if (getClass() != obj.getClass())
22             return false;
23         User other = (User) obj;
24         if (id == null) {
25             if (other.id != null)
26                 return false;
27         } else if (!id.equals(other.id))
28             return false;
29         return true;
30     }
31     
32     @Override
33     public String toString() {
34         return "User [id=" + id + ", num=" + num + "]";
35     }
36     
37     public User() {
38         
39     }
40     
41     public User(String id, int num) {
42         this.id = id;
43         this.num = num;
44     }
45     
46     public String getId() {
47         return id;
48     }
49     public void setId(String id) {
50         this.id = id;
51     }
52     public int getNum() {
53         return num;
54     }
55     public void setNum(int num) {
56         this.num = num;
57     }    
58 }

 1 package homework20191126;
 2 
 3 import java.util.ArrayList;
 4 
 5 public class Usermanager {
 6 
 7 private ArrayList list = new ArrayList();
 8     
 9     public void add(User user) {
10         list.add(user);
11     }
12     
13     public void showAll() {
14         System.out.println("***会员列表***");
15         System.out.println("编号\t积分");
16         User user;
17         for(Object obj : list) {
18             user = (User)obj;
19             System.out.println(user.getId()+"\t"+user.getNum());
20         }
21     }
22     
23     public User find(String id) {
24         User user = new User();
25         user.setId(id);
26         
27         int index = list.indexOf(user);
28         if(index == -1) {
29             return null;
30         }else {
31             return (User)list.get(index);
32         }
33     }
34 }

 1 package homework20191126;
 2 
 3 import java.util.Scanner;
 4 
 5 public class Testuser1 {
 6 
 7     public static void main(String[] args) {
 8         Scanner input = new Scanner(System.in);
 9         
10         String id;
11         int num;
12         User user;
13         
14         Usermanager m = new Usermanager();
15         
16         for(int i = 0; i < 4;i++) {
17             System.out.print("请输入会员编号：");
18             id = input.next();
19             System.out.print("请输入会员积分：");
20             num = input.nextInt();
21             
22             user = new User(id, num);
23             m.add(user);
24         }
25         
26         m.showAll();
27         
28         System.out.println("请输入要查找的会员编号：");
29         id = input.next();
30         
31         User user2 = m.find(id);
32         
33         if(user2 == null) {
34             System.out.println("没有找到");        
35         }else {
36             System.out.println("该会员积分为："+user2.getNum());
37         }
38     }
39 }