Shape接口，并定义抽象方法周长和面积

定义一个Shape接口，并定义抽象方法周长和面积，圆形类和长方形类分别去实现这个接口。最后在测试类里计算半径为5.6的周长和面积;长6.1，宽6.3的长方形的周长和面积

1. 测试类用Main代替

public class Main {

   public static void main(String[] args) {
       // TODO Auto-generated method stub
       // 最后在测试类里计算半径为5.6的周长和面积;长6.1，宽6.3的长方形的周长和面积

       Circular circular = new Circular(5.6);
       System.out.println("圆形的周长：" + circular.calcPerimeter());
       System.out.println("圆形的面积：" + circular.calcArea());

       Rectangle rectangle = new Rectangle(6.1,6.3);
       System.out.println("长方形的周长：" + rectangle.calcPerimeter());
       System.out.println("长方形的面积：" + rectangle.calcArea());

   }

}

2. 编写Shape接口

public interface Shape {

   // 计算面积
   double calcArea();

   // 计算周长
   double calcPerimeter();

}

3. 编写实现类圆形和长方形

public class Circular implements Shape{

   private double radius;



   @Override
   public String toString() {
       return "Circular [radius=" + radius + "]";
   }

   public double getRadius() {
       return radius;
   }

   public void setRadius(double radius) {
       this.radius = radius;
   }

   public Circular(double radius) {
       // TODO Auto-generated constructor stub
       this.radius = radius;
   }

   @Override
   public double calcArea() {
       // TODO Auto-generated method stub
       // 面积计算公式
       return Math.PI * this.radius * this.radius;
   }

   @Override
   public double calcPerimeter() {
       // TODO Auto-generated method stub
       // 周长计算公式
       return 2 * Math.PI * this.radius;
   }

}

public class Rectangle implements Shape{

   private double length;
   private double wide;

   public Rectangle(double length,double wide) {
       // TODO Auto-generated constructor stub
       this.length = length;
       this.wide = wide;
   }

   @Override
   public String toString() {
       return "Rectangle [length=" + length + ", wide=" + wide + "]";
   }

   public double getLength() {
       return length;
   }

   public void setLength(double length) {
       this.length = length;
   }

   public double getWide() {
       return wide;
   }

   public void setWide(double wide) {
       this.wide = wide;
   }

   @Override
   public double calcArea() {
       // TODO Auto-generated method stub
       // 面积计算公式
       return this.length * this.wide;
   }

   @Override
   public double calcPerimeter() {
       // TODO Auto-generated method stub
       // 周长计算公式
       return 2 * (this.length + this.wide);
   }
}

大体的目录结构：

public interface Shape {

    double getPerimeter(double x,double y);

    double getArea(double x,double y);

}

public class Circle implements Shape {
    /**
     * 获取周长
     *
     * @param x 半径
     * @param y 空
     * @return
     */
    @Override
    public double getPerimeter(double x, double y) {
        return 2 * Math.PI * x;
    }

    /**
     * 获取面积
     *
     * @param x 半径
     * @param y 空
     * @return
     */
    @Override
    public double getArea(double x, double y) {
        return Math.PI * Math.pow(x, 2);
    }
}


/**
 * 矩形
 */
public class Rect implements Shape{
    /**
     * 周长
     * @param x 长
     * @param y 宽
     * @return
     */
    @Override
    public double getPerimeter(double x, double y) {
        return (x+y)*2;
    }

    /**
     * 面积
     * @param x 长
     * @param y 宽
     * @return
     */
    @Override
    public double getArea(double x, double y) {
        return x*y;
    }
}

    @Test
    fun test2(){
        var circle:Shape=Circle()
        println(circle.getPerimeter(1.0,0.0))
        println(circle.getArea(1.0,0.0))

        var rect:Shape=Rect()
        println(rect.getPerimeter(1.0,2.0))
        println(rect.getArea(1.0,2.0))
    }

public class Test {

   public static void main(String[] args) {

       Shape circle = new Circle(5.6);
       System.out.println("圆的面积：" + circle.getArea());
       System.out.println("圆的周长：" + circle.getPerimeter());

       Shape rect = new Rectangle(6.1,6.3);
       System.out.println("矩形的面积：" + rect.getArea());
       System.out.println("矩形的周长：" + rect.getPerimeter());
   }

}
interface Shape{
double getArea();
double getPerimeter();
}

class Circle implements Shape{

   double radius; //半径
   public Circle() {}
   public Circle(double radius) {
       this.radius = radius;
   }
   @Override
   public double getArea() {
       return 3.14*radius*radius;
   }

   @Override
   public double getPerimeter() {
       return 2*radius*3.14;
   }
}
class Rectangle implements Shape{

   private double height;
   private double width;
   public Rectangle() {}
   public Rectangle(double height,double width) {
       this.height = height;
       this.width = width;
   }
   @Override
   public double getArea() {
       return width*height;
   }

   @Override
   public double getPerimeter() {
       return 2*height*width;
   }

}

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