编辑代码

import java.util.Date;
import java.lang.String;
import java.lang.Math;
class Main {
	public static void main(String[] args) {

        GeometricObject test =new GeometricObject();
        GeometricObject test1 =new GeometricObject("blue",true);

        GeometricObject cc = new Circle(5.0,"red", false);
        double ss = ((Circle)cc).getArea();
        System.out.println("矩形 %"+ss);


        GeometricObject rc = new Rectangle(12.0, 2.6, "white", true);


	}
    public static void area(GeometricObject gg){
        double s;
        if (gg instanceof Circle){
             s = ((Circle)gg).getArea();
            System.out.println("圆面积 %"+s);
	
        }else if ( gg instanceof Rectangle){
             s = ((Rectangle)gg).getArea();
            System.out.println("矩形 %"+s);
        }
        
    }
}


class GeometricObject{
    private String color;
    private boolean filled;
    private Date dateCreated;

    public GeometricObject(){};
    public GeometricObject(String color, boolean filled){
        this.color = color;
        this.filled = filled;}
    public String getColor(){return this.color;}
    public void setColor(String color){color = color;}

    public boolean isFilled(){return filled;}

    public void setFilled(boolean filled){

    }
    public Date getDateCreated(){return this.dateCreated;}
  
    public String toString(){return super.toString();}
}

class Circle extends GeometricObject{
    private double radius;
    public Circle(){}
    public Circle(double radius, String color, boolean filled){
        super(color, filled);
        this.radius = radius;}
    public double getRadius(){return radius;}
    public void setRadius(double radius){this.radius = radius;}
    public double getArea(){return getRadius()*getRadius()*Math.PI;}
}

class Rectangle extends GeometricObject{
    private double width;
    private double height;
    public Rectangle(){}
    public Rectangle(double width, double height){
    }
    public Rectangle(double width, double height, String color, boolean filled){
        super(color, filled);
        this.width = width;
        this.height = height;
    }
    public double getWidth(){return width;}
    public void setWidth(double width){this.width = width;}
    public void setHeight(double height){this.height = height;}
    public double getHeight(){return height;}
    public double getArea(){return getWidth()*getHeight();}
}