File Upload Don't work

DefaultController.php

<?php

    /**
     * @Route("/test", name="uploads3")
     * @Template()
     */
    public function testAction(){
       
    $document = new FBPost();
    $form = $this->createFormBuilder($document)
        ->add('name')
        ->add('file')
        ->getForm()
    ;

    if ($this->getRequest()->getMethod() === 'POST') {
        $form->bindRequest($this->getRequest());
        if ($form->isValid()) {
            $em = $this->getDoctrine()->getEntityManager();

            $document->upload();

            $em->persist($document);
            $em->flush();

            $this->redirect('useradmin');
        }
    }

?>

FBPost.php

<?php

namespace Nobox\SocialShowsBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\HttpFoundation\File\UploadedFile;


/**
 * @ORM\Entity
 * @ORM\HasLifecycleCallbacks
 */
class FBPost
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    public $id;

    /**
     * @ORM\Column(type="string", length=255)
     * @Assert\NotBlank
     */
    public $name;

    /**
     * @Assert\File(maxSize="6000000")
     */
    public $file;

    /**
     * @ORM\Column(type="string", length=255, nullable=true)
     */
    public $path;

    /**
     * @ORM\PrePersist()
     * @ORM\PreUpdate()
     */
    public function preUpload()
    {
        if (null !== $this->file) {
            // do whatever you want to generate a unique name
            $this->path = uniqid().'.'.$this->file->guessExtension();
        }
    }

    /**
     * @ORM\PostPersist()
     * @ORM\PostUpdate()
     */
    public function upload()
    {
        if (null === $this->file) {
            return;
        }

        // if there is an error when moving the file, an exception will
        // be automatically thrown by move(). This will properly prevent
        // the entity from being persisted to the database on error
        $this->file->move($this->getUploadRootDir(), $this->path);

        unset($this->file);
    }

    /**
     * @ORM\PostRemove()
     */
    public function removeUpload()
    {
        if ($file = $this->getAbsolutePath()) {
            unlink($file);
        }
    }

    public function getAbsolutePath()
    {
        return null === $this->path ? null : $this->getUploadRootDir().'/'.$this->path;
    }

    public function getWebPath()
    {
        return null === $this->path ? null : $this->getUploadDir().'/'.$this->path;
    }

    protected function getUploadRootDir()
    {
        // the absolute directory path where uploaded documents should be saved
        return __DIR__.'/../../../../web/'.$this->getUploadDir();
    }

    protected function getUploadDir()
    {
        // get rid of the __DIR__ so it doesn't screw when displaying uploaded doc/image in the view.
        return 'uploads/documents';
    }

    public function setFile(File $file)
    {
        $this->file = $file;
    }

    /**
    * @return \Symfony\Component\HttpFoundation\File\UploadedFile
    */
    public function getFile()
    {
        return $this->file;
    }

}

?>