利用面向对象来修改密码

import java.util.Scanner;

class Admin {
    String admin;
    int mm;

    public void gaimi() {
        System.out.println("用户名:"+admin+"n密码:"+mm);
    }
}

public class work2 {
    public static void main(String[] args) {
        Admin test = new Admin();
        test.admin = "cstyyds";
        test.mm = 123456;
        while (true) {
            System.out.println("输入旧的用户名:");
            Scanner sc = new Scanner(System.in);
            String oldadmin = sc.next();
            System.out.println("输入旧的密码:");
            int oldmm = sc.nextInt();
            if (oldadmin.equals(test.admin) && oldmm == test.mm) {
                System.out.println("认证成功!");
                System.out.println("请输入新密码:");
                int newadmin = sc.nextInt();
                test.mm = newadmin;
                System.out.print("更改密码成功!");
                break;
            } else {
                System.out.println("您输入的用户名或密码有误，请稍后再试.");
            }

        }
        System.out.println("新用户信息为:");
        test.gaimi();
    }
}