Controller/FileController.php
public function downloadAction(Request $request)
    {
        $key = $request->attributes->get('key');
        if (0 < strlen($key)) {
            $fs = $this->get('local_upload_filesystem');
            if ($fs->has($key)) {
                $file = $fs->get($key);

                // TODO 304 not modified

                $response = new StreamedResponse();

                // Set the headers
                $response->headers->set('Content-Type', $file->getMimetype());
                $response->headers->set('Content-Length', $file->getSize());

                // TODO http cache
                /*$this->setHttpCacheHeaders(
                    $lastModified,
                    md5($this->getCachePath() . $lastModified->getTimestamp()),
                    $this->maxAge
                );*/

                $response->setCallback(function () use ($file) {
                    fpassthru($file->readStream());
                });

                return $response;
            }
        }

        throw new NotFoundHttpException('File not found');
    }
public function downloadAction(Request $request)
    {
        $key = $request->attributes->get('key');
        if (0 < strlen($key)) {
            $fs = $this->get('local_upload_filesystem');
            if ($fs->has($key)) {
                $file = $fs->get($key);

                // TODO 304 not modified

                $response = new StreamedResponse();

                // Set the headers
                $response->headers->set('Content-Type', $file->getMimetype());
                $response->headers->set('Content-Length', $file->getSize());

                // TODO http cache
                /*$this->setHttpCacheHeaders(
                    $lastModified,
                    md5($this->getCachePath() . $lastModified->getTimestamp()),
                    $this->maxAge
                );*/

                $response->setCallback(function () use ($file) {
                    fpassthru($file->readStream());
                });

                return $response;
            }
        }

        throw new NotFoundHttpException('File not found');
    }
Download local file.

@param Request $request
@return BinaryFileResponse
@throws NotFoundHttpException