Java题定义接口Shape,包含俩个抽象方法

Question

2.定义接口Shape，包含两个抽象方法getArea()和getCircum(),
分别实现获取图形的面积和周长，抽象方法print()用于输出面积和周长。基于接口Shape定义矩形类Ranctangle和圆类Circle。
圆类包含数据成员有半径，矩形类包含数据成员的有长、宽。
成员通过构造方法进行初始化，每个类都要重写抽象方法getArea()和 getCircum():计算并获取面积和周长，并重写抽象方法print()。
测试类中实例化矩形类Ranctangle和圆类Circle，计算面积和周长，并输出。

Answer 1

接口Shape：
public interface Shape {
    double getArea();
    double getCircum();
    void print();
}
圆类Circle：
public class Circle implements Shape {
    private double radius;
    
    public Circle(double radius) {
        this.radius = radius;
    }
    
    public double getArea() {
        return Math.PI * radius * radius;
    }
    
    public double getCircum() {
        return 2 * Math.PI * radius;
    }
    
    public void print() {
        System.out.println("The area of the circle is: " + getArea());
        System.out.println("The circum of the circle is: " + getCircum());
    }
}
矩形类Ranctangle：
public class Rectangle implements Shape {
    private double length;
    private double width;
    
    public Rectangle(double length, double width) {
        this.length = length;
        this.width = width;
    }
    
    public double getArea() {
        return length * width;
    }
    
    public double getCircum() {
        return 2 * (length + width);
    }
    
    public void print() {
        System.out.println("The area of the rectangle is: " + getArea());
        System.out.println("The circum of the rectangle is: " + getCircum());
    }
}
测试类：
public class Test {
    public static void main(String[] args) {
        Shape circle = new Circle(2.0);
        circle.print();
        
        Shape rectangle = new Rectangle(2.0, 3.0);
        rectangle.print();
    }
}
输出结果：
The area of the circle is: 12.566370614359172
The circum of the circle is: 12.566370614359172
The area of the rectangle is: 6.0
The circum of the rectangle is: 10.0