发票基本类

public class Invoice {public void printInvoice() {System.out.println("打印发票正文");}
}

发票正文类

public class Decorator extends Invoice {protected Invoice ticket;public Decorator(Invoice ticket) {this.ticket = ticket;}@Overridepublic void printInvoice() {if (ticket != null) {ticket.printInvoice();}}
}

发票头部类

public class HeadDecorator extends Decorator {public HeadDecorator(Invoice ticket) {super(ticket);}@Overridepublic void printInvoice() {System.out.println("打印发票头");super.printInvoice();}
}

发票尾部类

public class FootDecorator extends Decorator {public FootDecorator(Invoice ticket) {super(ticket);}@Overridepublic void printInvoice() {super.printInvoice();System.out.println("打印发票尾");}
}

演示类

public class Demo {public static void main(String[] args) {Invoice t= new Invoice();Decorator ticket;ticket=new FootDecorator(new HeadDecorator(t));ticket.printInvoice();}
}

演示结果