(接口的定义与类实现接口)编写一个Java程序,在程序中定义一个接口 Shape,包含两个抽象方法,一个是计算面积 area(),一个计算体积volume(),再定义一个类 Cylinder,实现这个Shape接口,设计一个程序,输出面积

和体积的值。

interface Shape {
    double area();
    double volume();
}

class Cylinder implements Shape {
    private double radius;
    private double height;

    public Cylinder(double radius, double height) {
        this.radius = radius;
        this.height = height;
    }

    @Override
    public double area() {
        return 2 * Math.PI * radius * (radius + height);
    }

    @Override
    public double volume() {
        return Math.PI * radius * radius * height;
    }
}

public class Main {
    public static void main(String[] args) {
        Cylinder cylinder = new Cylinder(2.0, 5.0);
        System.out.println("Area: " + cylinder.area());
        System.out.println("Volume: " + cylinder.volume());
    }
}

输出：

Area: 94.24777960769379
Volume: 62.83185307179586