TYPO3 isDir，getRealPath在Controller上不起作用

What i would like to do, is to zip my fileadmin and my extension folder with a zipAction on my controller. So i took a piece of code from here and i have this:

$fileAdminPath = 'fileadmin';
$archiveName = $importerSettings['fileadminArchiveName'];
$zip = new \ZipArchive;
$zip->open($archiveName, \ZipArchive::CREATE | \ZipArchive::OVERWRITE);
$files = new \RecursiveIteratorIterator (new \RecursiveDirectoryIterator($fileAdminPath), \RecursiveIteratorIterator::LEAVES_ONLY);

if (!$file->isDir()) {
   // Get real and relative path for current file
   $filePath = $file->getRealPath();
   $relativePath = substr($filePath, strlen($fileAdminPath) + 1);
   // Add current file to archive
   $zip->addFile($filePath, $relativePath);
}

// Zip archive will be created only after closing object
$zip->close();

Now, when the code reaches the isDir() part, i get the following error:

Call to a member function isDir() on null

If i remove it and let the code run again, the getRealPath() gets the same error. So i am guessing i missing a namespace or something like that, that stores these functions.

On a local php file (index.php) and MAMPP it works. On TYPO3, not.

By the way, i am not sure if the controller really reads the fileadmin path. If i got it wrong, please feel free to correct me.

Best regards

If you run your script inside an extension, this script is searching fileadmin within your extension directory.

Try to use the following script:

$fileAdminPath = \TYPO3\CMS\Core\Utility\GeneralUtility::getFileAbsFileName('fileadmin');

Edit:

You should also walk the files in an foreach because you scan an directory recursiv:

foreach ($files as $file) {
  if (!$file->isDir()) {
    // Get real and relative path for current file
    $filePath = $file->getRealPath();
    $relativePath = substr($filePath, strlen($fileAdminPath) + 1);
    // Add current file to archive
    $zip->addFile($filePath, $relativePath);
  }
}