查找会员积分

package homework20191126;

public class User {

    private String id;
    private int num;
    
    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((id == null) ? 0 : id.hashCode());
        return result;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        User other = (User) obj;
        if (id == null) {
            if (other.id != null)
                return false;
        } else if (!id.equals(other.id))
            return false;
        return true;
    }
    
    @Override
    public String toString() {
        return "User [id=" + id + ", num=" + num + "]";
    }
    
    public User() {
        
    }
    
    public User(String id, int num) {
        this.id = id;
        this.num = num;
    }
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public int getNum() {
        return num;
    }
    public void setNum(int num) {
        this.num = num;
    }    
}

package homework20191126;

import java.util.ArrayList;

public class Usermanager {

private ArrayList list = new ArrayList();
    
    public void add(User user) {
        list.add(user);
    }
    
    public void showAll() {
        System.out.println("***会员列表***");
        System.out.println("编号\t积分");
        User user;
        for(Object obj : list) {
            user = (User)obj;
            System.out.println(user.getId()+"\t"+user.getNum());
        }
    }
    
    public User find(String id) {
        User user = new User();
        user.setId(id);
        
        int index = list.indexOf(user);
        if(index == -1) {
            return null;
        }else {
            return (User)list.get(index);
        }
    }
}

package homework20191126;

import java.util.Scanner;

public class Testuser1 {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        
        String id;
        int num;
        User user;
        
        Usermanager m = new Usermanager();
        
        for(int i = 0; i < 4;i++) {
            System.out.print("请输入会员编号：");
            id = input.next();
            System.out.print("请输入会员积分：");
            num = input.nextInt();
            
            user = new User(id, num);
            m.add(user);
        }
        
        m.showAll();
        
        System.out.println("请输入要查找的会员编号：");
        id = input.next();
        
        User user2 = m.find(id);
        
        if(user2 == null) {
            System.out.println("没有找到");        
        }else {
            System.out.println("该会员积分为："+user2.getNum());
        }
    }
}