魔术方法的使用

    server = $server;        $this->username = $username;        $this->password = $password;        $this->db = $db;        $this->connect();    }        private function connect()    {        $this->link = mysql_connect($this->server, $this->username, $this->password);        mysql_select_db($this->db, $this->link);    }        public function __sleep()    {        echo __METHOD__;        return array('server', 'username', 'password', 'db'); //序列化时保存这些属性    }        public function __wakeup()    {        $this->connect(); //反序列化后自动连接数据库        echo __METHOD__;    }}$conn = Connection('mysql://localhost:3306/','root','root123','db_php');unserilize(serialize($conn));?>

输出

__sleep__wakeup