1  public class CastingDemo {
  2    /** Main method */
  3    public static void main(String[] args) {
  4      // Create and initialize two objects
  5      Object object1 = new CircleFromSimpleGeometricObject(1);
  6      Object object2 = new RectangleFromSimpleGeometricObject(1, 1);
  7  
  8      // Display circle and rectangle
  9      displayObject(object1);
 10      displayObject(object2);
 11    }
 12  
 13    /** A method for displaying an object */
 14    public static void displayObject(Object object) {
 15      if (object instanceof CircleFromSimpleGeometricObject) {
 16        System.out.println("The circle area is " +
 17          ((CircleFromSimpleGeometricObject)object).getArea());
 18        System.out.println("The circle diameter is " +
 19          ((CircleFromSimpleGeometricObject)object).getDiameter());
 20      }
 21      else if (object instanceof 
 22                    RectangleFromSimpleGeometricObject) {
 23        System.out.println("The rectangle area is " +
 24          ((RectangleFromSimpleGeometricObject)object).getArea());
 25      }
 26    }
 27  }