<manifest> 
 <uses-permission android:name="android.permission.BLUETOOTH" />
 <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
 ...
</manifest>

BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
 // Device does not support Bluetooth
}

if (!mBluetoothAdapter.isEnabled()) {
 Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(intent, REQUEST_ENABLE_BT);
}

mBluetoothAdapter.startDiscovery();

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
 public void onReceive(Context context, Intent intent) {
  String action = intent.getAction();

  // 當(dāng)有設(shè)備被發(fā)現(xiàn)的時候會收到 action == BluetoothDevice.ACTION_FOUND 的廣播
  if (BluetoothDevice.ACTION_FOUND.equals(action)) {

   //廣播的 intent 里包含了一個 BluetoothDevice 對象
   BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

   //假設(shè)我們用一個 ListView 展示發(fā)現(xiàn)的設(shè)備，那么每收到一個廣播，就添加一個設(shè)備到 adapter 里
   mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
  }
 }
};
// 注冊廣播監(jiān)聽
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
//設(shè)置可被發(fā)現(xiàn)的時間，00s
intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(intent);

Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
 for (BluetoothDevice device : pairedDevices) {
  mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
 }
}

private class ConnectThread extends Thread {
 private final BluetoothSocket mmSocket;
 private final BluetoothDevice mmDevice;

 public ConnectThread(BluetoothDevice device) {

  BluetoothSocket tmp = null;
  mmDevice = device;
  try {
   // 通過 BluetoothDevice 獲得 BluetoothSocket 對象
   tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
  } catch (IOException e) { }
  mmSocket = tmp;
 }

 @Override
 public void run() {
  // 建立連接前記得取消設(shè)備發(fā)現(xiàn)
  mBluetoothAdapter.cancelDiscovery();
  try {
   // 耗時操作，所以必須在主線程之外進(jìn)行
   mmSocket.connect();
  } catch (IOException connectException) {
   //處理連接建立失敗的異常
   try {
    mmSocket.close();
   } catch (IOException closeException) { }
   return;
  }
  doSomething(mmSocket);
 }

 //關(guān)閉一個正在進(jìn)行的連接
 public void cancel() {
  try {
   mmSocket.close();
  } catch (IOException e) { }
 }
}

private class AcceptThread extends Thread {

 private final BluetoothServerSocket mmServerSocket;

 public AcceptThread() {

  BluetoothServerSocket tmp = null;
  try {
   // client 必須使用一樣的 UUID !!!
   tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID);
  } catch (IOException e) { }
  mmServerSocket = tmp;
 }

 @Override
 public void run() {
  BluetoothSocket socket = null;
  //阻塞操作
  while (true) {
   try {
    socket = mmServerSocket.accept();
   } catch (IOException e) {
    break;
   }
   //直到有有連接建立，才跳出死循環(huán)
   if (socket != null) {
    //要在新開的線程執(zhí)行，因為連接建立后，當(dāng)前線程可能會關(guān)閉
    doSomething(socket);
    mmServerSocket.close();
    break;
   }
  }
 }

 public void cancel() {
  try {
   mmServerSocket.close();
  } catch (IOException e) { }
 }
}

private class ConnectedThread extends Thread {
 private final BluetoothSocket mmSocket;
 private final InputStream mmInStream;
 private final OutputStream mmOutStream;

 public ConnectedThread(BluetoothSocket socket) {
  mmSocket = socket;
  InputStream tmpIn = null;
  OutputStream tmpOut = null;
  //通過 socket 得到 InputStream 和 OutputStream
  try {
   tmpIn = socket.getInputStream();
   tmpOut = socket.getOutputStream();
  } catch (IOException e) { }

  mmInStream = tmpIn;
  mmOutStream = tmpOut;
 }

 public void run() {
  byte[] buffer = new byte[1024]; // buffer store for the stream
  int bytes; // bytes returned from read()

  //不斷的從 InputStream 取數(shù)據(jù)
  while (true) {
   try {
    bytes = mmInStream.read(buffer);
    mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
      .sendToTarget();
   } catch (IOException e) {
    break;
   }
  }
 }

 //向 Server 寫入數(shù)據(jù)
 public void write(byte[] bytes) {
  try {
   mmOutStream.write(bytes);
  } catch (IOException e) { }
 }

 public void cancel() {
  try {
   mmSocket.close();
  } catch (IOException e) { }
 }
}