Reading an NDEF message from an NFC tag from an Android application

Question

I am trying to create an application using NFC, and I just want to try and read the NFC tag and get the text message from the tag and put it in the TextView. I already have a code for it, but nothing happens when I try to connect the phone with an NFC tag.

Here is my code, and someone can look at it and see what I am doing wrong and what needs to be done to fix the problem:

Button measurementsDataButton; NfcAdapter myNfcAdapter; PendingIntent myPendingIntent; IntentFilter ndef; IntentFilter[] filters; String[][] techLists; int mCount; TextView mText; String payload; byte payloadHeader; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_nfc_scanner); final ActionBar actionBar = getActionBar(); actionBar.setDisplayHomeAsUpEnabled(true); mText = (TextView) findViewById(R.id.flowTextView1); measurementsDataButton = (Button) findViewById(R.id.measurementsButton1); measurementsDataButton.setOnClickListener(this); myNfcAdapter = NfcAdapter.getDefaultAdapter(this); myPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); ndef = new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED); filters = new IntentFilter[] {ndef, }; techLists = new String[][] {new String[] {Ndef.class.getName()}, new String[] {NdefFormatable.class.getName()}}; } @Override public void onPause() { super.onPause(); myNfcAdapter.disableForegroundDispatch(this); } @Override public void onResume() { super.onResume(); if(myNfcAdapter != null) { myNfcAdapter.enableForegroundDispatch(this, myPendingIntent, filters, techLists); } } @Override public void onNewIntent(Intent intent) { if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent())) { NdefMessage [] messages = getNdefMessages(getIntent()); for(int i = 0; i<messages.length; i++) { for(int j = 0; j<messages[0].getRecords().length; j++) { NdefRecord record = messages[i].getRecords()[j]; payload = new String(record.getPayload(), 1, record.getPayload().length-1, Charset.forName("UTF-8")); mText.setText(payload); payloadHeader = record.getPayload()[0]; } } } } NdefMessage[] getNdefMessages(Intent intent) { // TODO Auto-generated method stub NdefMessage[] message = null; if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) { Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); if(rawMessages != null) { message = new NdefMessage[rawMessages.length]; for(int i = 0; i < rawMessages.length; i++) { message[i] = (NdefMessage) rawMessages[i]; } } else { byte[] empty = new byte[] {}; NdefRecord record = new NdefRecord (NdefRecord.TNF_UNKNOWN, empty, empty, empty); NdefMessage msg = new NdefMessage (new NdefRecord[] {record}); message = new NdefMessage[] {msg}; } } else { Log.d("", "Unknown intent."); finish(); } return message; } 

Answer 1

Sample code for sending and receiving NDEF TAG:

 public class MainActivity extends AppCompatActivity implements NfcAdapter.CreateNdefMessageCallback { private NfcAdapter mNfcAdapter; TextView tv; private PendingIntent mPendingIntent; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tv = (TextView) findViewById(R.id.textViewReceivedMessage); NfcManager nfcManager = (NfcManager) getSystemService(NFC_SERVICE); mNfcAdapter = nfcManager.getDefaultAdapter(); mPendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, getClass()) .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); } private static NdefMessage getTestMessage() { byte[] mimeBytes = "application/com.android.cts.verifier.nfc" .getBytes(Charset.forName("US-ASCII")); byte[] id = new byte[] {1, 3, 3, 7}; byte[] payload = "CTS Verifier NDEF Push Tag".getBytes(Charset.forName("US-ASCII")); return new NdefMessage(new NdefRecord[] { new NdefRecord(NdefRecord.TNF_MIME_MEDIA, mimeBytes, id, payload) }); } @Override protected void onResume() { super.onResume(); mNfcAdapter.enableForegroundDispatch(this, mPendingIntent, null, null); mNfcAdapter.setNdefPushMessageCallback(this, this); } // sending message @Override public NdefMessage createNdefMessage(NfcEvent event) { return getTestMessage(); } private NdefMessage[] getNdefMessages(Intent intent) { Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); if (rawMessages != null) { NdefMessage[] messages = new NdefMessage[rawMessages.length]; for (int i = 0; i < messages.length; i++) { messages[i] = (NdefMessage) rawMessages[i]; } return messages; } else { return null; } } static String displayByteArray(byte[] bytes) { String res=""; StringBuilder builder = new StringBuilder().append("["); for (int i = 0; i < bytes.length; i++) { res+=(char)bytes[i]; } return res; } // displaying message @Override protected void onNewIntent(Intent intent) { super.onNewIntent(intent); NdefMessage[] messages = getNdefMessages(intent); tv.setText(displayByteArray(messages[0].toByteArray())); } 

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