php設(shè)計模式之單例模式代碼
更新時間:2016年06月11日 09:50:21 作者:dongxiaojie
這篇文章主要為大家詳細介紹了php設(shè)計模式之單例模式的實現(xiàn)代碼,具有一定的參考價值,感興趣的朋友可以參考一下
php設(shè)計模式之單例模式的例子,供大家參考,具體內(nèi)容如下
<?php /** * php設(shè)計模式 單例模式 */ class Fruit{ private static $instanceMap = array(); //protected getter for singleton instances protected static function getSingleton($className){ //保證單例模式 并且不能從控制器實例化和克隆 if (!isset(self::$instanceMap[$className])) { $object = new $className; //Make sure this object inherit from Singleton if ($object instanceof Fruit) { self::$instanceMap[$className] = $object; var_dump($object); } else { throw SingletonException("Class '$className' do not inherit from Singleton!"); } } return self::$instanceMap[$className]; } //protected constructor to prevent outside instantiation protected function __construct(){} //denie cloning of singleton objects public final function __clone(){ trigger_error('It is impossible to clone singleton', E_USER_ERROR); } } class Apple extends Fruit{ protected $rndId; public function __construct(){ $this->rndId = rand(); } public function whatAmI(){ echo 'I am a Apple(' . $this->rndId . ')<br />'; } public static function getInstance(){ //echo get_class(); return Fruit::getSingleton(get_class()); } } class GreenApple extends Apple{ public function whatAmI(){ echo 'I am a GreenApple(' . $this->rndId . ')<br />'; } public static function getInstance(){ return Fruit::getSingleton(get_class()); } } $apple1 = Apple::getInstance(); //var_dump($apple1); $apple2 = GreenApple::getInstance(); $apple1->whatAmI();// should echo 'I am a Apple(some number) $apple2->whatAmI();// should echo 'I am a GreenApple(some number) $apple1 = Apple::getInstance(); $apple2 = GreenApple::getInstance(); //保證單例模式 $apple1->whatAmI();// should echo 'I am a Apple(same number as above) $apple2->whatAmI();// should echo 'I am a GreenApple(same number as above) // $a = clone $apple1;// this should fail // $b = clone $apple2;// this should fail
以上就是本文的全部內(nèi)容,希望對大家學(xué)習(xí)php程序設(shè)計有所幫助。
相關(guān)文章
Laravel框架使用技巧之使用url()全局函數(shù)返回前一個頁面的地址方法詳解
這篇文章主要介紹了Laravel框架使用技巧之使用url()全局函數(shù)返回前一個頁面的地址,需要的朋友可以參考下2020-04-04mysql 查詢指定日期時間內(nèi)sql語句實現(xiàn)原理與代碼
查詢指定日期時間內(nèi)sql語句實現(xiàn)原理:如果是月份就是當前的月減去你要統(tǒng)計的時間如我要查詢數(shù)據(jù)庫中從今天起往前三個月的所有記錄2012-12-12