/** *返回工厂实例 */ public static function factory() { //只实例一个对象 if (is_null(self::$sessionFactory)) { self::$sessionFactory = new SessionFactory(); } $driver = ucfirst(strtolower(C('SESSION_ENGINE'))); if (isset(self::$sessionFactory->driver[$driver])) { return self::$sessionFactory->driver[$driver]; } self::$sessionFactory->getDriver($driver); return self::$sessionFactory->driver[$driver]; }