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();
  }
} 

Circle with normal border
Shape: Circle

Circle of red border
Shape: Circle
Border Color: Red

Rectangle of red border
Shape: Rectangle
Border Color: Red