String extension = fileName.substring(lastDot);
String extension = fileName.substring(lastDot).toLowerCase(Locale.ENGLISH);
	public static boolean isArchiveFileName(String fileName) {		int lastDot = fileName.lastIndexOf('.');		if (lastDot < 0) {			return false;		}		String extension = fileName.substring(lastDot);		return ARCHIVE_EXTENSION_SET.contains(extension);	}