1.创建Door

public class Door {
    public void open(){
        System.out.println("开门");
    }

    public void close() {
        System.out.println("关门");
    }

}

2.创建KeypadDoor

public class KeypadDoor extends Door{

    public void open() {
        System.out.println("输入密码开门");
    }

    public void close() {
        System.out.println("轻轻关上，自动锁门");
    }
}

3.创建PowerDoor

public class PowerDoor extends Door {
    public void open() {
        System.out.println("按遥控开门");
    }

    public void close() {
        System.out.println("按遥控锁门");
    }
}

4.运行

public class Demo01 {
    public static void main(String[] args) {
        KeypadDoor keypadDoor = new KeypadDoor();
        keypadDoor.open();
        keypadDoor.close();

        PowerDoor powerDoor = new PowerDoor();
        powerDoor.open();
        powerDoor.close();


    }
}