stratepy pattern

public class Client {
  public static void main (String[] args) {
    System.out.println("start");
    Factory myFactory;
    myFactory = new Factory();
    Component myComponent = myFactory.getComponent();
    myComponent.prtTicket();
    System.out.println("end");
  }
}
abstract class Component {
  abstract public void prtTicket();
}
class SalesTicket extends Component {
  public void prtTicket() {
    System.out.println("売上伝票の印刷処理");
  }
}
abstract class TicketDecorator extends Component {
  private Component myComponent;
  public TicketDecorator(Component myComponent) {
    this.myComponent = myComponent;
  }
  public void callTrailer() {
    if (myComponent != null)
    myComponent.prtTicket();
  }
}
class Header1 extends TicketDecorator {
  public Header1(Component myComponent) {
    super(myComponent);
  }
  public void prtTicket() {
    System.out.println("ヘッダ１");
    callTrailer();
  }
}
class Header2 extends TicketDecorator {
  public Header2(Component myComponent) {
    super(myComponent);
  }
  public void prtTicket() {
    callTrailer();
    System.out.println("ヘッダ２");
  }
}
class Footer1 extends TicketDecorator {
  public Footer1(Component myComponent) {
    super(myComponent);
  }
  public void prtTicket() {
    callTrailer();
    System.out.println("フッタ1");
  }
}
class Footer2 extends TicketDecorator {
  public Footer2(Component myComponent) {
    super(myComponent);
  }
  public void prtTicket() {
    callTrailer();
    System.out.println("フッタ2");
  }
}
class Factory {
  public Component getComponent() {
    Component myComponent;
    myComponent = new SalesTicket();
    myComponent = new Footer2(myComponent);
    myComponent = new Footer1(myComponent);
    myComponent = new Header2(myComponent);
    myComponent = new Header1(myComponent);
    return myComponent;
  }
}