接口：Printable 方法：print()

抽象类：1：BlackPrinter 实现 Printable ，print输出：黑白打印；2：ColorPrinter 实现 Printable ，print输出：彩色打印

具体类：1：LaserPrinter，继承 BlackPrinter，输出：黑白打印，激光打印；具体类 2：JetInkPrinter 继承 ColorPrinter ，print输出：彩色打印，喷墨打印

测试类：声明接口Printable 变量p，new一个激光打印机，一个喷墨打印机，分别用p指向两个打印机，用p调用print方法

https://blog.csdn.net/m0_46824767/article/details/105697794 试试？

interface Printable {
    void print();
}

class BlackPrinter implements Printable {
    @Override
    public void print() {
        System.out.println("黑白打印");
    }
}

class ColorPrinter implements Printable {
    @Override
    public void print() {
        System.out.println("彩色打印");
    }
}

class LaserPrinter extends BlackPrinter {
    @Override
    public void print() {
        super.print();
        System.out.println("激光打印");
    }
}

class JetInkPrinter extends ColorPrinter {
    @Override
    public void print() {
        super.print();
        System.out.println("喷墨打印");
    }
}

public class Test {
    public static void main(String[] args) {
        LaserPrinter laserPrinter = new LaserPrinter();
        JetInkPrinter jetInkPrinter = new JetInkPrinter();
        Printable p = laserPrinter;
        p.print(); 
        p = jetInkPrinter;
        p.print(); 
    }
}