java接口多态

Java 评论

java接口多态

接口多态和类多态是一样的用法

定义格式:

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public interface 父接口{
	//内容
}
public class 类名A implements 父接口 {
	//内容
}
public class 类名B implements 父接口 {
	//内容
}

使用格式:

父接口类型 接口对象名 = new 类名();







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package xiaochenyan.top.demo003;

public class DemoMain{
    public static void main(String[] args) {
        Computer cm = new Computer();
        cm.open();
        cm.local(new usbMouse());
        cm.local(new usbKeyboard());
        cm.close();
    }
}
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package xiaochenyan.top.demo003;

public interface USB{
    public abstract void open();
    public abstract void close();
}
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package xiaochenyan.top.demo003;

public class usbKeyboard 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 qiaoJiJianPan(){
        System.out.println("敲击键盘");
    }
}
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package xiaochenyan.top.demo003;

public class usbMouse 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 shuBiaoDianJi(){
        System.out.println("鼠标点击");
    }
}
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package xiaochenyan.top.demo003;

public class Computer{
   public void open(){
        System.out.println("打开电脑");

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

    }
    //使用接口进行多态处理
    public void local(USB obj)
    {
        obj.open();

        if(obj instanceof usbMouse){
            ((usbMouse) obj).shuBiaoDianJi();

        }else if(obj instanceof usbKeyboard){
            ((usbKeyboard) obj).qiaoJiJianPan();

        }
        obj.close();
    }

}

YanChen

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