SourceMaking

public class DecoratorBefore {

 

static class A { public void doIt() { System.out.print( 'A' ); } }

 

static class AwithX extends A {

   public  void doIt() { super.doIt();  doX(); }

   private void doX()  { System.out.print( 'X' ); }

}

 

static class AwithY extends A {

   public void doIt() { super.doIt();  doY(); }

   public void doY()  { System.out.print( 'Y' ); }

}

 

static class AwithZ extends A {

   public void doIt() { super.doIt();  doZ(); }

   public void doZ()  { System.out.print( 'Z' ); }

}

 

static class AwithXY extends AwithX {

   private AwithY obj = new AwithY();

   public void doIt() {

      super.doIt();

      obj.doY();

}  }

 

static class AwithXYZ extends AwithX {

   private AwithY obj1 = new AwithY();

   private AwithZ obj2 = new AwithZ();

   public void doIt() {

      super.doIt();

      obj1.doY();

      obj2.doZ();

}  }

 

public static void main( String[] args ) {

   A[] array = { new AwithX(), new AwithXY(), new AwithXYZ() };

   for (int i=0; i < array.length; i++) {

      array[i].doIt();

      System.out.print( "  " );

}  }  }