在Codeigniter中从控制器调用其他控制器方法失败

Question

我想在admin controller中调用upload_controllers方法。我在这里附上了我的代码。但它不起作用。相反，它显示Unable to locate the specified class: Session.php

class Admin_controller extends CI_Controller {

     public function __construct() {
          parent::__construct();
          this->load->helper('url');
     }

     function index(){
          require_once(APPPATH.'controllers/uploads_controller.php');
          $testObj = new uploads_Controller();
          $testObj->index();
     }
 }