[php]php设计模式 Memento (备忘录模式)

<?php
 2 /**
 3  * 备忘录模式
 4  *
 5  * 在不破坏封装性的前提下,捕获一个对象的内部状态,并在该对象之外保存这个状态,这样以后就可以将该对象恢复到保存的状态
 6 */
 7 class Memento
 8 {
 9 private$_state=null;
10 
11 publicfunction __construct($state)
12     {
13 $this->_state =$state;
14     }
15 
16 publicfunction getState()
17     {
18 return$this->_state;
19     }
20 }
21 
22 class Caretaker
23 {
24 private$_memento=null;
25 
26 publicfunction getMemento()
27     {
28 return$this->_memento;
29     }
30 
31 publicfunction setMemento($memento)
32     {
33 $this->_memento =$memento;
34     }
35 }
36 
37 class Originator
38 {
39 private$_state=null;
40 
41 publicfunction getState()
42     {
43 return$this->_state;
44     }
45 
46 publicfunction setState($state)
47     {
48 $this->_state =$state;
49     }
50 
51 publicfunction createMemento()
52     {
53 returnnew Memento($this->_state);
54     }
55 
56 publicfunction setMemento($memento)
57     {
58 $this->_state =$memento->getState();
59     }
60 
61 publicfunction display()
62     {
63 echo"state = ".$this->_state."<br/>";
64     }
65 }
66 
67 $objOriginator=new Originator();
68 $objOriginator->setState(0);
69 $objOriginator->display();
70 
71 $objCareTaker=new CareTaker();
72 $objCareTaker->setMemento($objOriginator->createMemento());
73 
74 $objOriginator->setState(1);
75 $objOriginator->display();
76 
77 $objOriginator->setMemento($objCareTaker->getMemento());
78 $objOriginator->display();