获取错误：无法找到指定的类：Session.php

Getting Error while using Hook:-

i have already done $config['enable_hooks'] = TRUE; in autoload.php and also set encryption key..

config/Hook.php

$hook['pre_controller'] = array(
                                'class'    => 'Login_hook',
                                'function' => 'check_login_hook',
                                'filename' => 'Login_hook.php',
                                'filepath' => 'hooks'
                                );

hooks/Login_hook.php

<?php
class Login_hook extends CI_Controller{
    function check_login_hook(){

        if(isset($this->session->userdata['user_storage'])){
            echo $user_id=$this->session->userdata['user_storage']['s_u_id'];
            echo $user_id=$this->session->userdata['user_storage']['s_u_name'];
        }else{
            echo "n";
        }

    }
}
?>

Error is:-

Unable to locate the specified class: Session.php

Load library session in construct

class check_login_hook extends CI_Controller {
     public function __construct()
          {
             parent::__construct();
             $this->load->library('session');
          }

Open your autoload.php in applications/config/autoload.php

$autoload['libraries'] = array('session');

Open you config.php in

$config['base_url'] ='your base url';

also enable the helper class in autoload.php

$autoload['helper'] = array('url');