JAVA 装饰模式-2016软件设计师下半年考试真题

Posted on | Edited on | Comments:

题目要求：打印发票头、内容、底部的要求

BTW,八成这次软考又挂了…

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
class Invoice{
  public void printInvoice(){
    System.out.println("this is content");
  }
}
class Decorator extends Invoice{
  protected Invoice ticket;
  public Decorator (Invoice t){
    ticket=t;
  }
  public void printInvoice(){
    if(ticket!=null){
      ticket.printInvoice();
    }
  }
}
class HeaderDecorator extends Decorator{
  public HeaderDecorator(Invoice t){
    super(t);
  }
  public void printInvoice(){
    System.out.println("this is the header");
    super.printInvoice();
  }
}
class FooterDecorator extends Decorator{
  public FooterDecorator(Invoice t){
    super(t);
  }
  public void printInvoice(){
    super.printInvoice();
    System.out.println("this is the footer");
  }
}
public class zhuangshi {
  public static void main(String[] args){
    Invoice t =new Invoice();
    Invoice ticket;
    ticket=new FooterDecorator(new HeaderDecorator(t));
    ticket.printInvoice();
    System.out.println("=====================");
    ticket=new FooterDecorator(new HeaderDecorator(new Decorator(null)));
    ticket.printInvoice();
  }
}

这么写也行 ，不知道哪个算标准答案

1
2
3
4
5
6
7
Invoice t =new Invoice();
 Invoice ticket;
 ticket=new HeaderDecorator(new FooterDecorator(t));
 ticket.printInvoice();
 System.out.println("=====================");
 ticket=new HeaderDecorator(new FooterDecorator(null));
 ticket.printInvoice();

结果

图片描述