小结 3



public interface Shape {
   void draw();
}
public class Rectangle implements Shape {
   @Override
   public void draw() {
      System.out.println("Shape: Rectangle");
   }
}
public class Circle implements Shape {
   @Override
   public void draw() {
      System.out.println("Shape: Circle");
   }
}
public abstract class ShapeDecorator implements Shape {
   protected Shape decoratedShape;
   public ShapeDecorator(Shape decoratedShape){
      this.decoratedShape = decoratedShape;
   }
   public void draw(){
      decoratedShape.draw();
   }	
}
public class RedShapeDecorator extends ShapeDecorator {
   public RedShapeDecorator(Shape decoratedShape) {
      super(decoratedShape);		
   }
   @Override
   public void draw() {
      decoratedShape.draw();	       
      setRedBorder(decoratedShape);
   }
   private void setRedBorder(Shape decoratedShape){
      System.out.println("Border Color: Red");
   }
}
public class DecoratorPatternDemo {
   public static void main(String[] args) {
      Shape circle = new Circle();
      Shape redCircle = new RedShapeDecorator(new Circle());
      Shape redRectangle = new RedShapeDecorator(new Rectangle());
      System.out.println("Circle with normal border");
      circle.draw();
      System.out.println("\nCircle of red border");
      redCircle.draw();
      System.out.println("\nRectangle of red border");
      redRectangle.draw();
   }
}