private void validateFileName(String fileName) throws InvalidFileException {
		Pattern pattern = Pattern.compile(FILE_NAME_REGEXP);
		Matcher matcher = pattern.matcher(fileName);
		if (matcher.matches()) {
			File file = new File(fileName);
			if (!file.exists() || file.isDirectory())
				throw new InvalidFileException("File is not exists.");
		} else
			throw new InvalidFileException("Incorrect file name.");
	}