I would ignore what the Google documentation says for reading at https://developer.android.com/guide/topics/connectivity/nfc/nfc and for read/write at https://developer.android.com/guide/topics/connectivity/nfc/advanced-nfc#read-write as this provides a very poor user experience for writing to Tags and leads to a lot of failed writes because of user behaviour.
To get reliable writing to NFC with Android you should use the newer and much better enableReaderMode API https://developer.android.com/reference/android/nfc/NfcAdapter
Using this newer API leads to a lot less failed writes and corrupted cards because you can control when the notification sound happens. With the old Intent based system the system pauses your app and then reads the card and makes a notification sound, the user then removes the card before your App is resumed and has a chance to handle the card data and write to the card.
With the newer enableReaderMode API you turn off the system notification sound and your App is never paused to read the NFC card, you can then read and write to the card and then when you have successfully written to the card you can make the notification sound yourself.
Because any errors are silent, the user will keep trying to present the card until the success Notification. Additional logic is needed not to write the same message every time a single card or different cards are presented.
Some example code (adapted from my NFC app to handle low level reading and writing (not Ndef Tag technology))
public class NFCActivity extends AppCompatActivity implements NfcAdapter.ReaderCallback{
private NfcAdapter mNfcAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nfc);
mNfcAdapter = NfcAdapter.getDefaultAdapter(this);
// Rest of Activity setup
}
@Override
protected void onResume() {
super.onResume();
if(mNfcAdapter!= null) {
Bundle options = new Bundle();
// Work around for some broken Nfc firmware implementations that poll the card too fast
options.putInt(NfcAdapter.EXTRA_READER_PRESENCE_CHECK_DELAY, 250);
// Enable ReaderMode for all types of card and disable platform sounds
mNfcAdapter.enableReaderMode(this,
this,
NfcAdapter.FLAG_READER_NFC_A |
NfcAdapter.FLAG_READER_NFC_B |
NfcAdapter.FLAG_READER_NFC_F |
NfcAdapter.FLAG_READER_NFC_V |
NfcAdapter.FLAG_READER_NFC_BARCODE |
NfcAdapter.FLAG_READER_NO_PLATFORM_SOUNDS,
options);
}
}
@Override
protected void onPause() {
super.onPause();
if(mNfcAdapter!= null)
mNfcAdapter.disableReaderMode(this);
}
// This method is run in another thread when a card is discovered
// !!!! This method cannot cannot direct interact with the UI Thread
// Use `runOnUiThread` method to change the UI from this method
@Override
public void onTagDiscovered(Tag tag) {
// Read and or write to Tag here to the appropriate Tag Technology type class
// in this example the card should be an Ndef Technology Type
Ndef mNdef = Ndef.get(tag);
// Check that it is an Ndef capable card
if (mNdef!= null) {
// If we want to read
// As we did not turn on the NfcAdapter.FLAG_READER_SKIP_NDEF_CHECK
// We can get the cached Ndef message the system read for us.
NdefMessage mNdefMessage = mNdef.getCachedNdefMessage();
// Or if we want to write a Ndef message
// Create a Ndef Record
NdefRecord mRecord = NdefRecord.createTextRecord("en","English String");
// Add to a NdefMessage
NdefMessage mMsg = new NdefMessage(mRecord);
// Catch errors
try {
mNdef.connect();
mNdef.writeNdefMessage(mMsg);
// Success if got to here
runOnUiThread(() -> {
Toast.makeText(getApplicationContext(),
"Write to NFC Success",
Toast.LENGTH_SHORT).show();
});
// Make a Sound
try {
Uri notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
Ringtone r = RingtoneManager.getRingtone(getApplicationContext(),
notification);
r.play();
} catch (Exception e) {
// Some error playing sound
}
} catch (FormatException e) {
// if the NDEF Message to write is malformed
} catch (TagLostException e) {
// Tag went out of range before operations were complete
} catch (IOException e){
// if there is an I/O failure, or the operation is cancelled
} catch (SecurityException e){
// The SecurityException is only for Android 12L and above
// The Tag object might have gone stale by the time
// the code gets to process it, with a new one been
// delivered (for the same or different Tag)
// The SecurityException is thrown if you are working on
// a stale Tag
} finally {
// Be nice and try and close the tag to
// Disable I/O operations to the tag from this TagTechnology object, and release resources.
try {
mNdef.close();
} catch (IOException e) {
// if there is an I/O failure, or the operation is cancelled
}
}
}
}
