数据库会话PHP Mongo

Question

我正在使用mongoDB和PHP为我的网页创建一个登录部分。目前我可以验证我的用户凭据，检查它是否真实。我的问题是，当我登录时，它不会在php中保持会话。我从一本书中获取了一些代码，其中展示了如何将会话存储在我的mongoDB数据库中。我很确定它必须是有错误的会话，因为它不会将信息带到下一页。

我的会话代码

    <?php
    require_once('dbconnection.php');
    class SessionManager
    {
        //name of collection where sessions will be stored
        const COLLECTION = 'sessions';
        //Expire session after 10 mins in inactivity
        const SESSION_TIMEOUT = 600;
        //Expire session after 1 hour
        const SESSION_LIFESPAN = 3600;
        //name of the session cookie
        const SESSION_NAME = 'mongosessid';
        const SESSION_COOKIE_PATH = '/';
        const SESSION_COOKIE_DOMAIN = '';
        private $_mongo;
        private $_collection;
        private $_currentSession;
        public function __construct()
        {
            $this->_mongo = DBConnection::instantiate();
            $this->_collection = $this->_mongo->
            getCollection(SessionManager::COLLECTION);
            session_set_save_handler(
            array(&$this, 'open'),
            array(&$this, 'close'),
            array(&$this, 'read'),
            array(&$this, 'write'),
            array(&$this, 'destroy'),
            array(&$this, 'gc')
            );
            //Set session garbage collection period
            ini_set('session.gc_maxlifetime',
            SessionManager::SESSION_LIFESPAN);
            //set session cookie configurations
            session_set_cookie_params(
            SessionManager::SESSION_LIFESPAN,
            SessionManager::SESSION_COOKIE_PATH,
            SessionManager::SESSION_COOKIE_DOMAIN
            );
            //Replace 'PHPSESSID' with 'mongosessid' as the
            //session name
            session_name(SessionManager::SESSION_NAME);
            session_cache_limiter('nocache');
            //start the session
            session_start();
        }
        public function open($path, $name)
        {
            return true;
        }
        public function close()
        {
            return true;
        }
        public function read($sessionId)
        {
            $query = array(
                    'session_id' => $sessionId,
                    'timedout_at' => array('$gte' => time()),
                    'expired_at' => array('$gte' => time() -
                    SessionManager::SESSION_LIFESPAN)
            );
            $result = $this->_collection->findOne($query);
            $this->_currentSession = $result;
            if(!isset($result['data']))
            {
                return '';
            }
            return $result['data'];
        }
        public function write($sessionId, $data)
        {
            $expired_at = time() + self::SESSION_TIMEOUT;
            $new_obj = array(
                    'data' => $data,
                    'timedout_at' =>
                    time() + self::SESSION_TIMEOUT,
                    'expired_at' =>
                    (empty($this->_currentSession)) ?
                    time()+ SessionManager::SESSION_LIFESPAN
                    : $this->_currentSession['expired_at']
            );
            $query = array('session_id' => $sessionId);
            $this->_collection->update(
                    $query,
                    array('$set' => $new_obj),
                    array('upsert' => True)
            );
            return True;
        }
        public function destroy($sessionId)
        {
            $this->_collection->remove(array('session_id' =>
                    $sessionId));
            return True;
        }
        public function gc()
        {
            $query = array( 'expired_at' => array('$lt' => time()));
            $this->_collection->remove($query);
            return True;
        }
        public function __destruct()
        {
            session_write_close();
        }
    }
    //initiate the session
    $session = new SessionManager

();

user.php的

<?php
require_once('dbconnection.php');
require_once('session.php');
class User
{
    const COLLECTION = 'users';
    private $_mongo;
    private $_collection;
    private $_user;
    public function __construct()
    {
        $this->_mongo = DBConnection::instantiate();
        $this->_collection = $this->_mongo->
        getCollection(User::COLLECTION);
        if ($this->isLoggedIn()) $this->_loadData();
    }
    public function isLoggedIn()
    {
        return isset($_SESSION['user_id']);
    }
    public function authenticate($username, $password)
    {
        $query = array(
                'username' => $username,
                'password' => $password
        );
        $this->_user = $this->_collection->findOne($query);
        if (empty($this->_user)) return False;
        $_SESSION['user_id'] = (string) $this->_user['_id'];
        return True;
    }
    public function logout()
    {
        unset($_SESSION['user_id']);
    }
    public function __get($attr)
    {
        if (empty($this->_user))
            return Null;
        switch($attr)
        {
            case 'address':
                $address = $this->_user['address'];
                return sprintf('country: %s, city: %s, street: %',  $address['country'],
                        $address['city'], $address['street']);
            case 'city':
                return $this->_user['address']['city'];
            case 'country':
                return $this->_user['address']['country'];
            case 'password':
                return NULL;
            default:
                return (isset($this->_user[$attr])) ?
                $this->_user[$attr] : NULL;
        }
    }
    private function _loadData()
    {
        $id = new MongoId($_SESSION['user_id']);
        $this->_user = $this->_collection->findOne(array('_id'
                => $id));
    }
}

我的两个php / HTML页面

<?php
$action = (!empty($_POST['login']) &&
        ($_POST['login'] === 'Log in')) ? 'login'
                : 'show_form';
switch($action)
{
    case 'login':
        require('session.php');
        require('user.php');
        $user = new User();
        $username = $_POST['username'];
        $password = $_POST['password'];
        if ($user->authenticate($username, $password))
        {
            header('location: startpage.php');
            exit;
        }
        else
        {
            $errorMessage = "Username/password did not match.";
            break;
        }
    case 'show_form':
    default:
        $errorMessage = NULL;
}
?>

Seconcd php / HTML页面（不含HTML）

<?php
            require('session.php');
            require('user.php');
            $user = new User();
            if (!$user->isLoggedIn())
            {
                header('location: index.php');
                exit;
            }
            else {
                header('location: startpage.php');
                break;
            }
      ?>

感谢任何帮助，感谢所有读过这些代码的人。