Class Image zf2 with doctrine

Image.php

<?php
namespace User\Entity;

use Doctrine\ORM\Mapping as ORM,
    Doctrine\Common\Collections\ArrayCollection;

/**
 * Description of Image
 *
 * @author dudu
 */
/**
 * @ORM\Entity
 * @ORM\Table(name="image")
 * @ORM\HasLifecycleCallbacks
 */
class Image
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

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

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

    public function getId()
    {
        return $this->id;
    }

    public function getNom()
    {
        return $this->nom;
    }

    public function setNom($nom)
    {
        $this->nom = $nom;
    }

    public function getPath()
    {
        return $this->path;
    }

    public function setPath($path)
    {
        $this->path = $path;
    }

    public function getFile()
    {
        return $this->file;
    }

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

    public function getUploadRootDir()
    {
        return __DIR__.'/../../../../../public/'.$this->getUploadDir();
    }

    protected function getUploadDir()
    {
        return 'uploads/image/';
    }

    /**
     * @ORM\PrePersist()
     * @ORM\PreUpdate()
     */
    public function preUpload()
    {
        if (null !== $this->file) {
            $guessExtension = explode('.', $this->file['name']);
            $this->path = sha1(uniqid(mt_rand(), true)).'.'.$guessExtension[count($guessExtension)-1];
        }
    }

    /**
     * @ORM\PostPersist()
     * @ORM\PostUpdate()
     */
    public function upload()
    {
        if (null === $this->file) {
            return;
        }
        move_uploaded_file ($this->file['tmp_name'],$this->getUploadRootDir().$this->path);
        unset($this->file);
    }

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