Flyweight.java

public interface Shape {
    void draw(); 
}
//------------------------------------------------------

//------------------------------------------------------
// Circle.java
// Classe Circle, implementando a interface Shape
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);
    }
}
//------------------------------------------------------

//------------------------------------------------------
// ShapeFactory.java
// Classe Factory para produzir e controlar Shapes
import java.util.HashMap;

public class ShapeFactory {

   @SuppressWarnings("unchecked")
   private static final HashMap 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;
   }
}
//------------------------------------------------------

//------------------------------------------------------
// FlyweightPatternDemo.java
// Classe cliente que utiliza nosso factory
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);
   }
}