A question regarding the above title
Why does my data transferred via serial port keeps on buffering? The android cannot recognize the data as a data. It cannot write the data received and transferred to the tag on the android device

This is the sendFileToTag function:

 public boolean sendFileToTag(Tag detectedTag, int sectorOrPage) {
        try {
            // Give the exact filePath
            String filePath = "/storage/self/primary/Upload_in_NFC.txt";

            // Read the file data
            String fileData = readFileAsString(filePath);

            // Encode the file data into an NDEF message
            byte[] ndefData = encodeNdefData(fileData);

            // Construct the NFC_Write command
            byte[] nfcWriteCommand = new byte[]{
                    (byte) 0xAA,  // Start byte
                    0x00,         // Length (variable, depends on the data being sent)
                    0x2C,         // Command byte for NFC_Write (0x94)
                    (byte) sectorOrPage, // Sector/Page (replace this with the appropriate sector or page number)
                    (byte) (ndefData.length + 1), // Length of NDEF data
                    0x01          // Start of NDEF data
                    // NDEF data goes here
                    // You may need to convert the fileData to bytes and place it here
            };

            // Write the NFC_Write command to the tag
            byte[] responseData = sendNFCCommand(detectedTag, nfcWriteCommand);

            // Check the response for errors
            if (responseData != null && responseData.length > 0 && responseData[0] == (byte) 0x00) {
                // Write successful
                byte[] cardNumber = Arrays.copyOfRange(responseData, 1, responseData.length);
                System.out.println("File data written to NFC tag");
                System.out.println("Card Number: " + asciiToHex(new String(cardNumber, StandardCharsets.US_ASCII)));
                return true;
            } else {
                // Handle the case where there was an error in the response
                showToast("NFC Write Error");
            }
        } catch (IOException e) {
            // Handle file reading error
            e.printStackTrace();
        }
        return false;
    }

This is the serial port configuration:

   // Find and open the USB serial port
        UsbSerialPort serialPort = findSerialPort(); // Implement the method to find the appropriate serial port

        try {
            // Open the serial port and configure parameters
            serialPort.open(usbManager.openDevice(serialPort.getDriver().getDevice()));
            // Configure parameters
            serialPort.setParameters(9600, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);

            // Create a buffer to read the data
            byte[] buffer = new byte[1024];
            int totalBytesRead = 0;
            int MAX_DATA_SIZE = 1024; // Define your maximum data size here


            // Read data from the serial port
            while (true) {
                int bytesRead = serialPort.read(buffer, 1000); // Adjust the timeout value as needed

                // Convert the received bytes to a string
                if (bytesRead > 0) {
                    // Append the received bytes to the data
                    dataFromSerial += new String(buffer, 0, bytesRead);
                    totalBytesRead += bytesRead;


                    // Check for termination condition or end of transmission
                    if (dataFromSerial.contains("terminator")) {
                        break; // Exit the loop if the terminator is found
                    }

                    // Check for maximum data size or other conditions
                    if (totalBytesRead >= MAX_DATA_SIZE) {
                        break; // Exit the loop if maximum data size is reached
                    }
                } else {
                    // No more data to read
                    break;
                }
            }

This is the writeDataToFile:

   public void writeDataToFile(File directory, NdefMessage ndefMessage) {
        try {
            if (directory != null) {
                File file = new File(directory, "nfc_data.txt");
                try (FileOutputStream fos = new FileOutputStream(file)) {
                    // Process each NDEF record
                    if (ndefMessage != null) {
                        NdefRecord[] records = ndefMessage.getRecords();
                        for (NdefRecord record : records) {
                            // Assuming the record contains text data
                            if (record.getTnf() == NdefRecord.TNF_WELL_KNOWN &&
                                    Arrays.equals(record.getType(), NdefRecord.RTD_TEXT)) {
                                // Decode the payload data
                                String dataFromNdef = new String(record.getPayload(), StandardCharsets.UTF_8);
                                // Write the NDEF data to the file
                                fos.write(("NDEF Data: " + dataFromNdef + "n").getBytes(StandardCharsets.UTF_8));
                            }
                        }
                    }
                    Log.d("FileIO", "NFC Data written to file: " + file.getAbsolutePath());
                } catch (IOException e) {
                    Log.e("FileIO", "Error writing to file: " + e.getMessage());
                }
            } else {
                Log.e("FileIO", "Directory is null, cannot write to file.");
            }
        } catch (Exception e) {
            Log.e("FileIO", "Error: " + e.getMessage());
        }
    }