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

package com.biggw.day10.demo07;

/**
 * @author gw
 * @date 2019/11/2 0002 下午 16:46
 */
public class Computer {
    public void open() {
        System.out.println("打开电脑!");
    }

    public void close() {
        System.out.println("关闭电脑!");
    }

    public void useDevice(Usb usb) {
        if (usb instanceof KeyBorad) {
            KeyBorad keyBorad = (KeyBorad) usb;
            keyBorad.open();
            keyBorad.type();
            keyBorad.close();
        } else if (usb instanceof Mouse) {
            Mouse mouse = (Mouse) usb;
            mouse.open();
            mouse.click();
            mouse.close();
        }
    }
}

package com.biggw.day10.demo07;

/**
 * @author gw
 * @date 2019/11/2 0002 下午 16:42
 */
public interface Usb {
    public abstract void open();

    public abstract void close();
}

package com.biggw.day10.demo07;

/**
 * @author gw
 * @date 2019/11/2 0002 下午 16:44
 */
public class Mouse implements Usb {
    @Override
    public void open() {
        System.out.println("打开鼠标！");
    }

    @Override
    public void close() {
        System.out.println("关闭鼠标!");
    }

    public void click() {
        System.out.println("点击鼠标!");
    }
}

package com.biggw.day10.demo07;

/**
 * @author gw
 * @date 2019/11/2 0002 下午 16:43
 */
public class KeyBorad implements Usb {
    @Override
    public void open() {
        System.out.println("打开键盘!");
    }

    @Override
    public void close() {
        System.out.println("关闭键盘!");
    }

    public void type() {
        System.out.println("键盘输入文字!");
    }
}

package com.biggw.day10.demo07;

/**
 * @author gw
 * @date 2019/11/2 0002 下午 16:52
 */
public class Main {
    public static void main(String[] args) {
        Usb usb = new KeyBorad();
        Usb usb1 = new Mouse();

        Computer computer = new Computer();
        computer.open();
        computer.useDevice(usb);
        computer.useDevice(usb1);
        computer.close();

        /*点击鼠标!
        打开电脑!
        打开键盘!
        键盘输入文字!
        关闭键盘!
        打开鼠标！
        关闭鼠标!
        关闭电脑!*/
    }
}