BluetoothConnector

Class Overview

Allows two devices to establish a Bluetooth connection after exchanging an NFC Connection Handover Request. The socket is returned via callback.

A simple example for establishing a Bluetooth connection when both phones are in the same activity:

 MyActivity extends Activity {
   Nfc mNfc;
   
   BluetoothConnector.OnConnectedListener mBtListener =
           new BluetoothConnector.OnConnectedListener() {
       
       public void onConnectionEstablished(BluetoothSocket socket, 
               boolean isServer) {
          Log.d(TAG, "Connected over Bluetooth as " +
              (isServer ? "server" : "client"));
       }
   }
   
   public void onCreate(Bundle bundle) {
     super.onCreate(bundle);
     mNfc = new Nfc(this);
     BluetoothConnector.prepare(mNfc, mBtListener);
   }

   public void onResume() {
     super.onResume();
     mNfc.onResume(this);
   }
   
   public void onPause() {
     super.onPause();
     mNfc.onPause();
   }
   
   public void onNewInent(Intent intent) {
     if (mNfc.onNewIntent(this, intent)) return;
   }
 }
 

A more complex example, which supports:

• Pairing when both phones are in the same activity
• Pairing when only one phone is in the activity
• Providing a download link if your application is not yet installed.

You should also ensure that Bluetooth and Nfc are enabled on the device.

 public class MyActivity extends Activity {
  private Nfc mNfc;
  private Long mLastPausedMillis = 0L;

  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      mNfc = new Nfc(this);

      // If this activity was launched from an NFC interaction, start the
      // Bluetooth connection process.
      if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) {
          BluetoothConnector.join(mNfc, mBluetoothConnected, getNdefMessages(getIntent())[0]);
      } else {
          // If both phones are running this activity, or to allow remote
          // device to join from home screen.
          BluetoothConnector.prepare(mNfc, mBluetoothConnected, getAppReference());
      }
  }

  protected void onResume() {
      super.onResume();
      mNfc.onResume(this);
  }

  protected void onPause() {
      super.onPause();
      mLastPausedMillis = System.currentTimeMillis();
      mNfc.onPause(this);
  }

  protected void onNewIntent(Intent intent) {
      // Check for "warm boot" if the activity uses singleInstance launch mode:
      if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(intent.getAction())) {
          Long ms = System.currentTimeMillis() - mLastPausedMillis;
          if (ms > 150) {
              BluetoothConnector.join(mNfc, mBluetoothConnected, getNdefMessages(intent)[0]);
              return;
          }
      }
      if (mNfc.onNewIntent(this, intent)) {
          return;
      }
  }

  public NdefRecord[] getAppReference() {
      byte[] urlBytes = "http://example.com/funapp".getBytes();
      NdefRecord ref = new NdefRecord(NdefRecord.TNF_ABSOLUTE_URI, NdefRecord.RTD_URI, new byte[]{}, urlBytes);
      return new NdefRecord[] { ref };
  }

  OnConnectedListener mBluetoothConnected = new OnConnectedListener() {
      public void onConnectionEstablished(BluetoothSocket socket, boolean isServer) {
          toast("connected! server: " + isServer);
      }
  };

  private void toast(final String text) {
      runOnUiThread(new Runnable() {
          public void run() {
              Toast.makeText(MyActivity.this, text, Toast.LENGTH_SHORT).show();
          }
      });
  }

  private NdefMessage[] getNdefMessages(Intent intent) {
      if (!intent.hasExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)) {
          return null;
      }
      Parcelable[] msgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
      NdefMessage[] ndef = new NdefMessage[msgs.length];
      for (int i = 0; i < msgs.length; i++) {
          ndef[i] = (NdefMessage) msgs[i];
      }
      return ndef;
  }
 }
 

You will also need to add an intent filter to your application's manifest:

   <activity android:name=".MyActivity">
        <intent-filter>
            <action android:name="android.nfc.action.NDEF_DISCOVERED" />
            <category android:name="android.intent.category.DEFAULT" />
            <data android:scheme="http"
                  android:host="example.com"
                  android:path="/funapp" />
        </intent-filter>
   </activity>
 

For devices supporting SDK 14 and above, the handover record also includes an Android Application Record, allowing your application to be discovered in the market if it is not yet installed. Otherwise, the uri provided by getAppReference() should direct the user to a web page relevant to your application.

Summary

Nested Classes
interface	BluetoothConnector.OnConnectedListener	A callback used when a Bluetooth connection has been established.

Public Constructors
	BluetoothConnector()

Public Methods
static void	join(Nfc nfc, BluetoothConnector.OnConnectedListener conn, NdefMessage ndef) Extracts the Bluetooth socket information from an ndef message and connects as a client.
static BluetoothServerSocket	prepare(Nfc nfc, BluetoothConnector.OnConnectedListener conn) Configures the Nfc interface to set up a Bluetooth socket with another device.
static BluetoothServerSocket	prepare(Nfc nfc, BluetoothConnector.OnConnectedListener conn, NdefRecord[] ndef) Configures the Nfc interface to set up a Bluetooth socket with another device.

[Expand] Inherited Methods
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait() final void wait(long arg0, int arg1) final void wait(long arg0)