Java题定义接口Shape,包含俩个抽象方法

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。

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

代码如下，如有帮助望采纳

public interface Shape {
    //定义getArea方法
    double getArea();
    //定义getCircum方法
    double getCircum();

    //输出周长和面积
    void print();
}
import java.math.BigDecimal;

//矩形类
public class Ranctangle implements Shape{
    //长
    private String length;
    //宽
    private String width;
    //无参构造方法
    public Ranctangle() {

    }
    //有参构造方法
    public Ranctangle(String length, String width) {
        this.length = length;
        this.width = width;
    }
    @Override
    public double getArea() {
        //使用bigdecimal防止计算double类型的浮点数精度丢失
        BigDecimal length = new BigDecimal(this.length);
        BigDecimal width = new BigDecimal(this.width);
        return length.multiply(width).doubleValue();
    }

    @Override
    public double getCircum() {
        //使用bigdecimal防止计算double类型的浮点数精度丢失
        BigDecimal length = new BigDecimal(this.length);
        BigDecimal width = new BigDecimal(this.width);
        return length.add(width).doubleValue();
    }

    @Override
    public void print() {
        System.out.println("矩形周长为：" + getCircum());
        System.out.println("矩形面积为：" + getArea());
    }
}
import java.math.BigDecimal;

//圆类
public class Circle implements Shape{
    //定义成员变量半径radius
    private String radius;
    //构造方法
    public Circle() {

    }
    //有参构造方法
    public Circle(String radius) {
        this.radius = radius;
    }
    @Override
    public double getArea() {
        BigDecimal radius = new BigDecimal(this.radius);
        BigDecimal a = new BigDecimal("3.14");
        return a.multiply(radius).multiply(radius).doubleValue();
    }

    @Override
    public double getCircum() {
        BigDecimal radius = new BigDecimal(this.radius);
        BigDecimal a = new BigDecimal("3.14");
        BigDecimal b = new BigDecimal("2");
        return a.multiply(radius).multiply(b).doubleValue();
    }

    @Override
    public void print() {
        System.out.println("圆形周长为：" + getCircum());
        System.out.println("圆形面积为：" + getArea());
    }
}
//测试类
public class Test {
    public static void main(String[] args) {
        //定义矩形和圆形对象
        Shape ranctangle = new Ranctangle("2", "3.1");
        Shape circle = new Circle("2");
        ranctangle.print();
        circle.print();
    }
}

输出结果如下