Source of RoundShape.java

Structures and functions

  1: //RoundShape.java
  2: //An abstract class

  4: public abstract class RoundShape
  5: {
  6:     //Note this "inner class".
  7:     //It is used somewhat as a C++ struct might be used.
  8:     protected class Center
  9:     {
 10:         int x;
 11:         int y;
 12:     }

 14:     protected Center centerOfRoundShape = new Center();
 15:     protected double radiusOfRoundShape;


 18:     //Constructor
 19:     public RoundShape(int xCenter, int yCenter, double radius)
 20:     {        
 21:         centerOfRoundShape.x = xCenter;
 22:         centerOfRoundShape.y = yCenter;
 23:         radiusOfRoundShape = radius;
 24:     }


 27:     //Example of an abstract method
 28:     abstract public double getArea();
 29:     //Such a method *must* be implemented in any derived class.
 30:     //Or, the derived class must itself be declared abstract.
 31: }