gistfile1.txt

public static Observable<String> resetClock(NfcA nfca, long timestamp) {
        return Observable.fromCallable(() -> {
            prepareToIO(nfca);
            writeOperationCommand(nfca,
                    NfcOperationFactory.getCommandForTimeSetup(timestamp));
            //checkForOperationSuccess(nfca); //////////////////
            try {
                selectSector(nfca, SECTOR_3);
            } catch (Exception e) {
                throw new NfcOperationException("select sector 3" + e.getMessage());
            }

            byte[] record = new byte[4];
            byte[] command = new byte[] {COMMAND_READ_RECORD, (byte) (249)};
            DateTime startTime = DateTime.now().plusSeconds(1);
            while (true) {
                try {
                    record = nfca.transceive(command);
                } catch (Exception e) {
                }
                if (startTime.isBeforeNow()) {
                    throw new NfcOperationException("timed out");
                }
                if ((record[2] & 8) == 8) {
                    break;
                }
            }
            ////////////////////////////////////////////
            return readOperationAnswer(nfca);
        });
    }