GeneratePdfController.php

<?php
class GeneratePdfController extends AbstractActionController
{
    public function indexAction()
    {
      $filename = '/path/to/myFile.pdf';
      $response = new Stream();
      $headers = new Headers();
      $headers
          ->addHeaderLine('Pragma', 'public')
          ->addHeaderLine('Cache-Control', 'must-revalidate, post-check=0, pre-check=0')
          ->addHeaderLine('Content-Type', 'application/pdf')
          ->addHeaderLine('Content-disposition', 'inline; filename="' . basename($filename) . '";')
          ->addHeaderLine('Content-Transfer-Encoding', 'binary')
          ->addHeaderLine('Content-Length', filesize($filename))
          ->addHeaderLine('Accept-Ranges', 'bytes');
      $response->setHeaders($headers);
      $response->setContentLength(filesize($filename));
      $response->setStream(fopen($filename, 'r'));
      return $response;
    }
}