在学习java期间如何利用java制作一个简单的猜拳游戏编程？

import java.util.Scanner;
 
public class Game {
    private Scanner scan = new Scanner(System.in);
    private String rule[] = {"","剪刀","石头","布"};
    private String role[] = {"","刘备","孙权","曹操"};
    private Computer computer;
    private User user;
    private int roundCount;
    private Game(){
        roundCount = 0;
    }
    public static void main(String[] args) {
        Game game = new Game();
        game.start();
    }
    public  void start(){
        computer = new Computer();
        System.out.println("- - 欢迎进入游戏世界 - -");
        System.out.println("** ******************");
        System.out.println("** 猜拳，开始 **");
        System.out.println("** ******************");
        System.out.println();
        System.out.println("出拳规则：1.剪刀 2.石头 3.布");
        System.out.print("请选择角色（1：刘备 2.孙权 3.曹操）");
        int userRole = scan.nextInt();
        if(userRole >=1 && userRole <=3){
            user = new User(role[userRole]);
            System.out.println();
            System.out.print("要开始吗？（y/n） ");
            String start = scan.next();
            if(start.equals("y")){
                round();
            }
            else if(start.equals("n")){
                 
            }
        }
    }
    private void round(){
        roundCount ++;
        System.out.println();
        System.out.print("请出拳:1.剪刀 2.石头 3.布 (输入相应数字): ");
        int userRule = user.round();
        if(userRule >= 1 && userRule <= 3){
            int computerRule = computer.round();
            judge(userRule,computerRule);
            System.out.println();
            System.out.print("是否开始下一轮（y/n）: ");
            String next = scan.next();
            if(next.equals("y")){
                round();
            }
            else if(next.equals("n")){
                end();
            }
        }
    }
    private void judge(int ur,int cr){
        System.out.println("你出拳："+ rule[ur]);
        System.out.println("电脑出拳："+ rule[cr]);
        if(ur == cr){
            System.out.println("结果：和局，真衰！嘿嘿，等着瞧吧！");
        }
        else if((ur == 1 && cr== 3)||
                (ur == 2 && cr == 1)||
                (ur == 3 && cr == 2)){
            System.out.println("结果：你赢了！");
            user.win();
        }
        else{
            System.out.println("结果：你输了！");
            computer.win();
        }
    }
    private void end(){
        System.out.println("- -------------------------------------");
        System.out.println(user.getName() + "VS" + computer.getName());
        System.out.println("对战次数:" + roundCount);
        if(computer.getWin() == user.getWin()){
            System.out.println("结果:打成平手,下次再和你一分高下！");
        }
        else if(computer.getWin() > user.getWin()){
            System.out.println("结果：你输了！电脑赢了" + computer.getWin()+"次！");
        } 
        else{
            System.out.println("结果：你赢了！你赢了" + user.getWin()+"次！");
        }
        System.out.println("- -------------------------------------");
    }
    class Computer{
        private int win;
        private String name;
        public Computer(){
            win = 0;
            name = "匿名";
        }
        public int round(){
             
            return (int)(System.currentTimeMillis() % 3) + 1;//随机返回1、2、3
        }
        public String getName(){
            return name;
        }
        public void win(){
            win ++;
        }
        public int getWin(){
            return win;
        }
    }
    class User{
        private int win;
        private String name = "";
        public User(String name){
            this.name = name;
            win = 0;
        }
        public int round(){
            return scan.nextInt();
        }
        public String getName(){
            return name;
        }
        public void win(){
            win ++;
        }
        public int getWin(){
            return win;
        }
    }
}