人机猜拳

import java.util.Scanner;
　public class Person {
    Scanner input = new Scanner(System.in);
       String name;
    int score;
    String action;
    int num;
      public void method() {
        System.out.println("
请出拳：1.剪刀 2.石头 3.布");
        boolean a = true;
        do {

            num = input.nextInt();
            if (num == 1 || num == 2 || num == 3) {
                switch (num) {
                case 1:
                    action = "剪刀";
                    break;
                case 2:
                    action = "石头";
                    break;
                case 3:
                    action = "布";
                    break;
                }
                a = false;
                System.out.println("你出拳：" + action);
            } else {
                System.out.println("输入数字有误,请重新输入");
            }

        } while (a);
    }
}

第二个类，电脑类：

  public class Computer {
         String name;
    int score;
    String action;
    int num;
         public void method(){
                  num=(int)((Math.random())*3)+1;
        switch(num){
        case 1:
            action="剪刀";
            break;
        case 2:
            action="石头";
            break;
        case 3:
            action="布";
            break;
        }
        System.out.println(name+"出拳："+action);
        
    }
}
                                    

第三个类，游戏类：

import java.util.Scanner;

public class Game {
    Scanner input = new Scanner(System.in);
        Person person = new Person();//创建玩家类的对象
    Computer computer = new Computer();//创建电脑类的对象
    int number;
    int frequency = 0;
        public void process() {
        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("请选择对方角色（1:刘备2:孙权3:曹操）:");
        boolean b = true;
        do {
            number = input.nextInt();
            if (number == 1 || number == 2 || number == 3) {
                switch (number) {
                case 1:
                    computer.name = "刘备";
                    break;
                case 2:
                    computer.name = "孙权";
                    break;
                case 3:
                    computer.name = "曹操";
                    break;

                }
                b = false;
            } else {
                System.out.println("输入数字有误,请重新输入");
            }
        } while (b);
        System.out.print("请输入你的姓名：");
        person.name = input.next();
        System.out.println(person.name + "  VS  " + computer.name + "  对战
");
        System.out.println("要开始吗？(y/n)");
        char answer = input.next().charAt(0);
        while (answer == 'y') {
            person.method();
            computer.method();
            if (person.num == computer.num) {
                System.out.println("嘿嘿，和局，等着瞧吧！");
            } else if (((person.num == 2) && (computer.num == 1))
                    || (person.num == 1) && (computer.num == 3)
                    || ((person.num == 3) && (computer.num == 2))) {
                System.out.println("哇，你赢了，好厉害！");
                person.score++;
            } else {
                System.out.println("^_^!!!你输了，真笨！");
                computer.score++;
            }
            frequency++;
            System.out.println("
");
            System.out.println("还要继续吗？(y/n)");
            answer = input.next().charAt(0);
        }
    }
       public void showResult() {
        System.out.println("********************************");
        System.out.println(person.name + "  VS  " + computer.name);
        System.out.println("对战次数：" + frequency);
        System.out.println("
姓名		得分");
        System.out.println(person.name + "		" + person.score);
        System.out.println(computer.name + "		" + computer.score);
        if (person.score < computer.score) {
            System.out.println("呵呵，笨笨，下次加油！");
        } else if (person.score == computer.score) {
            System.out.println("哇，竟然平局，我们下次一决胜负！");
        } else {
            System.out.println("哇，你好棒啊！");
        }
        System.out.println("********************************");

    }
}

测试类：

public class Demo {
public static void main(String[] args) {
    Game play=new Game();//创建游戏类的对象
    play.process();//调用游戏类的游戏进程方法
    play.showResult();//调用游戏类的结算方法
}
}