public function getFilesFromDirectories(array $directoryArray)
    {
        $directoryArray = $this->getAbsoluteDirectoryPath($directoryArray);
        if (is_array($directoryArray) && count($directoryArray)) {
            $files = array();
            foreach ($directoryArray as $directory) {
                $foundFiles = GeneralUtility::getAllFilesAndFoldersInPath(
                    array(),
                    $directory,
                    $this->indexerConfig['fileext']
                );

                if (is_array($foundFiles) && count($foundFiles)) {
                    foreach ($foundFiles as $file) {
                        $files[] = $file;
                    }
                }
            }
            return $files;
        } else {
            return array();
        }
    }