tatic boolean checkExtension(String path) {
        int lastIndex;
        lastIndex = path.length() - 1;
        char[] pathToFile = path.toCharArray();
        if (pathToFile[lastIndex] != 't' || pathToFile[lastIndex - 1] != 'x' ||
pathToFile[lastIndex - 2] != 't' || pathToFile[lastIndex - 3] != '.') {
            System.out.println("Файл имеет неверное расширение. ");
            return false;
        }
        return true;
    }