public void run() {
            try {
                FileLock fl = fc.lock(start, end, false);
                System.out.println("Заблокировано: " + start + " to " + end);
                while (buff.position() < buff.limit() - 1)
                    buff.put((byte)(buff.get()+1));
                fl.release();
                System.out.println("Освобождено: " + start + " to " + end);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }