不要把界面的发给我，刚学几天看不懂QWQ，主要是如何吧随机数验证码加到用户名下面，各位大佬看看我目前写的QWQ，请毫不留情的鞭挞我吧，会努力的。
public static void main(String[] args) {
        // TODO Auto-generated method stub
        String zname = "Joh";
        String zaddress = "12345";
        int num = (int)(Math.random()*9999-999);
        Scanner input = new Scanner(System.in);
        System.out.println("用户名");
        String name = input.next();
        System.out.println("密码");
        String address = input.next();
    }

谢谢大大。。我知道怎么写了。。。今天刚写出来辜负了一片美意_(:з」∠)_，下面是我写的代码
import java.util.*;
public class OAdenglu {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String zname = "John";
        String zaddress = "123456";
        
        for(int i=0;i<3;i++){
            int znum = (int)(Math.random()*9999);//生成4位随机数
            Scanner input = new Scanner(System.in);
            System.out.println("用户名");
            String name = input.nextLine();
            System.out.println("密码");
            String address = input.nextLine();
            System.out.println("验证码"+znum);
            int num=input.nextInt();
            
            if(!name.equals(zname)){
                System.out.println("用户名错误请重新登录。");
            }else if(!address.equals(zaddress)){
                System.out.println("密码错误请重新登录。");
            }else if(num!=znum){
                System.out.println("验证码错误请重新登录。");
            }else{
                System.out.println("您好John，欢迎登录OA管理系统。");
                break;
            }
        }
        System.out.println("退出系统。");//退出及验证正确用户名 密码 验证码

    }

}