Java 接口和多态练习
我们鼠标和键盘实现USB接口,那么我们鼠标和键盘就变成了USB设备,这时候我们就可以把它放到笔记本电脑里面去用 1 package com.biggw.day10.demo07; 2 3 /** 4 * @author gw 5 * @date 2019/11/2 0002 下午 16:46 6 */ 7 public class Computer { 8 public void open() { 9 System.out.println("打开电脑!"); 10 } 11 12 public void close() { 13 System.out.println("关闭电脑!"); 14 } 15 16 public void useDevice(Usb usb) { 17 if (usb instanceof KeyBorad) { 18 KeyBorad keyBorad = (KeyBorad) usb; 19 keyBorad.open(); 20 keyBorad.type(); 21 keyBorad.close(); 22 } else if (usb instanceof Mouse) { 23 Mouse mouse = (Mouse) usb; 24 mouse.open(); 25 mouse.click(); 26 mouse.close(); 27 }