Java 多态性的使用

package com.bytezreo.duotai3;

/***
 * 
 * @Description  练习多态性的使用
 * @author  Bytezero·zhenglei!      Email:420498246@qq.com
 * @version
 * @date 2021年9月24日上午8:46:24
 * @     
 * 编写 equalsArea 方法测试两个对象的面积是否相等（注意方法的参数类型，利用动态绑定技术）
 * 编写 displayGeometricObject方法显示对象的面积（注意方法的参数类型，利用动态绑定技术）
 * 
 *
 */
public class GeometricTest
{
    public static void main(String[] args)
    {
        GeometricTest test = new GeometricTest();
    
        Circle c1 = new Circle(2.3,"black",5.0);
        test.displayGeometricObject(c1);
        
        Circle c2 = new Circle(4.3,"red",5.0);
        test.displayGeometricObject(c2);
         boolean isEquals = test.equalsArea(c1, c2);
         System.out.println("c1和c2的面积是否相等：" + isEquals);
        
        Circle c3 = new Circle(2.3,"black",5.0);
        test.displayGeometricObject(c3);
        
        boolean isEquals1 = test.equalsArea(c1, c3);
        System.out.println("c1和c3的面积是否相等：" + isEquals1);
        
        MyRectangle r1  = new MyRectangle(2.2,3.3,"red",1.0);
        test.displayGeometricObject(r1);
        
        
        
    }
    
    
    //GeometricObject o  = new Circle(...);
    public void displayGeometricObject(GeometricObject o)
    {
        System.out.println("面积为:"+ o.findAre());
    }
    
    
    
    //测试两个对象的面积是否相等
    public boolean equalsArea(GeometricObject o1,GeometricObject o2)
    {
         return o1.findAre() == o2.findAre();
    }
    
    
    
    
}

package com.bytezreo.duotai3;

public class GeometricObject    //几何图形
{
    protected  String color;
    protected  double weight;
    public String getColor() {
        return color;
    }
    public void setColor(String color) {
        this.color = color;
    }
    public double getWeight() {
        return weight;
    }
    public void setWeight(double weight) {
        this.weight = weight;
    }
//    public GeometricObject()
//    {
//        
//    }
    public GeometricObject(String color, double weight) {
        super();
        this.color = color;
        this.weight = weight;
    }
    
    
    public double findAre()
    {
       return 0.0;    
    }
    
}

package com.bytezreo.duotai3;

public class Circle extends GeometricObject
{
    
    private double radius;

    public Circle(double radius,String color, double weight) 
    {
        super(color, weight);
        
        this.radius = radius;
        
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }
    
    @Override
    public double findAre()
    {
        // TODO Auto-generated method stub
        return 3.14 *radius *radius;
    }
    

    
    
    
    
    
    
}

package com.bytezreo.duotai3;

public class MyRectangle extends GeometricObject
{
    private double width;
    private double height;

    public MyRectangle( double width, double height,String color, double weight)
    {
        super(color, weight);
        this.width = width;
        this.height = height;
        
        
        
    }

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }
    
    
    @Override
    public double findAre() 
    {
        
        return width * height;
    }
    
    

}