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);   
     double sss = (test1).getarea();
     GeometricObject cc = new Circle(5.0,"red",false);
     double ss = ((Circle)cc).getarea();
     System.out.println("矩形 %"+sss);
     System.out.println("矩形 %"+ss);
	}
    public static void area(GeometricObject gg)
    {
        double s;
        if (gg instanceof Circle)
        {
            s = ((Circle)gg).getarea();
            System.out.println("圆面积 %"+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)
    {
        filled = filled;
    }
    public Date getdateCreated()
    {
        return this.dateCreated;
    }
    public String toString()
    {
        return super.toString();
    }
      public double getarea()
    {
        return 2100;
    }
}

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;
    }
}