JAVA HashMap的运用（Demo片段）

package basic.day12;

import java.util.HashMap;
import java.util.Scanner;

public class HashMapDemo {
  public static void main(String[] args) {
    HashMap users = new HashMap();
    users.put("Tom", new User("Tom", "123", 25));// 通过put放入一个键值
    users.put("Jerry", new User("Jerry", "456", 26));
    users.put("Andy", new User("Andy", "789", 27));
    System.out.println(users);
    Scanner s = new Scanner(System.in);
    while (true) {
      System.out.println("用户名:");
      String name = s.nextLine();
      System.out.println("密码:");
      String pwd = s.nextLine();
      if (!users.containsKey(name)) {
        System.out.println("没有注册!");
        continue;
      }
      User user = (User) users.get(name);
      if (user.pwd.equals(pwd)) {
        System.out.println("欢迎登录！");
        break;
      }
    }
  }
}