Flyweight پترن در جاوا (Design Pattern)

public interface Shape {

     void draw();

}

public class Circle implements Shape {

     private String color;

     private int x;

     private int y;

     private int radius;



     public Circle(String color) {

          this.color = color;

     }



     public void setX(int x) {

          this.x = x;

     }



     public void setY(int y) {

          this.y = y;

     }



     public void setRadius(int radius) {

          this.radius = radius;

     }



     @Override

     public void draw() {

          System.out.println("Circle: Draw() [Color : " + color + ", x : " + x

                   + ", y :" + y + ", radius :" + radius);

     }

}

import java.util.HashMap;

public class ShapeFactory {
   private static final HashMap<String, Shape> circleMap = new HashMap();

   public static Shape getCircle(String color) {
      Circle circle = (Circle)circleMap.get(color);

      if(circle == null) {
         circle = new Circle(color);
         circleMap.put(color, circle);
         System.out.println("Creating circle of color : " + color);
      }
      return circle;
   }
}

public class FlyweightPatternDemo {
     private static final String colors[] = { "Red", "Green", "Blue", "White",
              "Black" };

     public static void main(String[] args) {

          for (int i = 0; i < 20; ++i) {
              Circle circle = (Circle) ShapeFactory.getCircle(getRandomColor());
              circle.setX(getRandomX());
              circle.setY(getRandomY());
              circle.setRadius(100);
              circle.draw();
          }
     }

     private static String getRandomColor() {
          return colors[(int) (Math.random() * colors.length)];
     }

     private static int getRandomX() {
          return (int) (Math.random() * 100);
     }

     private static int getRandomY() {
          return (int) (Math.random() * 100);
     }
}