php设计模式之备忘录模式

<?php/**  * 备忘录模式  *  * 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 */class Memento {private $_state = null;public function __construct($state) {$this->_state = $state;}public function getState() {return $this->_state;}}class Caretaker {private $_memento = null;public function getMemento() { return$ this->_memento;}public function setMemento($memento) {$this->_memento = $memento;}}class Originator {private $_state = null;public function getState() {return $this->_state;}public function setState($state) {$this->_state = $state;}public function createMemento() {return new Memento ( $this->_state );}public function setMemento($memento) {$this->_state = $memento->getState ();}public function display() {echo "state = " . $this->_state . "<br/>";}}$objOriginator = new Originator ();$objOriginator->setState ( 0 );$objOriginator->display ();$objCareTaker = new CareTaker ();$objCareTaker->setMemento ( $objOriginator->createMemento () );$objOriginator->setState ( 1 );$objOriginator->display ();$objOriginator->setMemento ( $objCareTaker->getMemento () );$objOriginator->display ();