前言

这是一个多态的实例，模拟鼠标、键盘插入拔出，面向对象思想

一、实例步骤

1.创建接口

/*
* USB接口==规范
* */
public interface USB {
    //拔出 插入
    void connect();
    void unconnect();
}

2.创建鼠标、键盘、电脑类

Mouse


public class Mouse implements USB {
    private String name;

    public Mouse(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public void connect() {
        System.out.println(name+"成功接入电脑");
    }

    @Override
    public void unconnect() {
        System.out.println(name+"成功拔出电脑");
    }
    /*
     * 独有功能
     * */
    public void dbClick(){
        System.out.println(name+"点击鼠标");
    }
}

KeyBoard


public class KeyBoard implements USB{
    private String name;

    public KeyBoard(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public void connect() {
        System.out.println(name+"成功接入电脑");
    }

    @Override
    public void unconnect() {
        System.out.println(name+"成功拔出电脑");
    }
    /*
    * 独有功能
    * */
    public void keyDown(){
        System.out.println(name+" 敲击键盘");
    }

}

Computer


public class Computer {
    private String name;

    public String getName() {
        return name;
    }
    public void start(){
        System.out.println(name+"电脑开机了");
    }
/*
* 提供安装USB设备的入口
* */
    public void installUSB(USB usb){
        //多态：usb可能是鼠标也可能是键盘
        usb.connect();
        //独有功能：先判再强转
        if(usb instanceof KeyBoard){
            KeyBoard k= (KeyBoard) usb;
            k.keyDown();
        }else if(usb instanceof Mouse) {
            Mouse m= (Mouse) usb;
            m.dbClick();
        }
        usb.unconnect();
    }


    public void setName(String name) {
        this.name = name;
    }

    public Computer(String name) {
        this.name = name;
    }
}

3.创建测试类

package com.xxf.polymorphic_test;
/*
* 目标：USB设备模拟
* 1、定义USB接口：插入、拔出
* 2、定义两个USB实现类：鼠标、键盘。
* 3、创建一个电脑对象，创建USB设备对象，安装启动
* */
public class Test {
    //a、创建电脑对象
    public static void main(String[] args) {
    Computer c=new Computer("神船");
    c.start();
     //b、创建一个鼠标、键盘对象
     USB u=new KeyBoard("双飞燕");
     c.installUSB(u);
     USB u1=new Mouse("罗技");
     c.installUSB(u1);

}
   }