Symfony2名称空间声明

Question

我正在尝试理解这个错误，但没有结果。我认为命名空间已正确写入脚本但仍会显示错误。也许Symfony在命名空间之前添加了一些代码？

Namespace declaration statement has to be the very first statement in the script in C:\xampp\htdocs\progetti\Symfony\src\Stefano\ZulliBundle\Security\Core\User\FOSUBUserProvider.php line 3

脚本是这样的：

<?php

namespace Stefano\ZulliBundle\Security\Core\User;

use HWI\Bundle\OAuthBundle\OAuth\Response\UserResponseInterface;
use HWI\Bundle\OAuthBundle\Security\Core\User\FOSUBUserProvider as BaseClass;
use Symfony\Component\Security\Core\User\UserInterface;

class FOSUBUserProvider extends BaseClass
{

/**
 * {@inheritDoc}
 */
public function connect(UserInterface $user, UserResponseInterface $response)
{
    $property = $this->getProperty($response);
    $username = $response->getUsername();

    //on connect - get the access token and the user ID
    $service = $response->getResourceOwner()->getName();

    $setter = 'set'.ucfirst($service);
    $setter_id = $setter.'Id';
    $setter_token = $setter.'AccessToken';

    //we "disconnect" previously connected users
    if (null !== $previousUser = $this->userManager->findUserBy(array($property => $username))) {
        $previousUser->$setter_id(null);
        $previousUser->$setter_token(null);
        $this->userManager->updateUser($previousUser);
    }

    //we connect current user
    $user->$setter_id($username);
    $user->$setter_token($response->getAccessToken());

    $this->userManager->updateUser($user);
}

/**
 * {@inheritdoc}
 */
public function loadUserByOAuthUserResponse(UserResponseInterface $response)
{
    $username = $response->getUsername();
    $user = $this->userManager->findUserBy(array($this->getProperty($response) => $username));
    //when the user is registrating
    if (null === $user) {
        $service = $response->getResourceOwner()->getName();
        $setter = 'set'.ucfirst($service);
        $setter_id = $setter.'Id';
        $setter_token = $setter.'AccessToken';
        // create new user here
        $user = $this->userManager->createUser();
        $user->$setter_id($username);
        $user->$setter_token($response->getAccessToken());
        //I have set all requested data with the user's username
        //modify here with relevant data
        $user->setUsername($username);
        $user->setEmail($username);
        $user->setPassword($username);
        $user->setEnabled(true);
        $this->userManager->updateUser($user);
        return $user;
    }

    //if user exists - go with the HWIOAuth way
    $user = parent::loadUserByOAuthUserResponse($response);

    $serviceName = $response->getResourceOwner()->getName();
    $setter = 'set' . ucfirst($serviceName) . 'AccessToken';

    //update access token
    $user->$setter($response->getAccessToken());

    return $user;
}

}