Android: basic usage of NFC

gistfile1.java

NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(getApplicationContext());

if ( nfcAdapter == null ) { 
  // Alert user that his device is incompatible
  // or deal with it in different way
  Log.w("nfc-test", "No NFC adapter present"); 
} else {
  if ( nfcAdapter.isEnabled() ) {
    // Everything ok: NFC present and enabled.
    Log.d("nfc-test", "NFC enabled");
  } else {
    // NFC present, but disabled. Deal with it.
    Log.d("nfc-test", "NFC disabled");
    
    // On example, user can be presented with settings
    // screen, where he can enable NFC.
    alertNfcDisabled();
  }
}

private void alertNfcDisabled () {
  AlertDialog.Builder b = new AlertDialog.Builder(this);
  b.setTitle("NFC disabled")
    .setMessage("You have NFC disabled. Please enable it in the system settings.")
    .setPositiveButton("Open settings", new DialogInterface.OnClickListener() {
      @Override
      public void onClick(DialogInterface dialog, int which) {
        // Open Settings app on the Wireless Settings tab, so it is easy
        // for the user to enable NFC.
        ParentClass.this.startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));
      }
    });
  return b.create();
}