Android 蓝牙开发详述

在AndroidSDK sample中给出了一个蓝牙聊天的示例代码，本文只是略作修改变成一个简单的服务器和客户端模式的应用，以适应在游戏开发中一对一关联的数据传输。

由于游戏中的蓝牙设置在新线程中发生，所以采用Handler的方式将蓝牙的状态以及读取信息传输给显示Activity。

1 开启蓝牙，包括xml中的配置: 

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

  //获取蓝牙适配器
 BluetoothAdapter btAdapter = BlueToothService.getInstance().getBtAdapter();
 //开启蓝牙
 if (!btAdapter.isEnabled()) {

          Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);

          startActivityForResult(enableIntent, ConstantsUtil.ENABLE_BLUETOOTH);

 }

 2 在当前Activity中获取蓝牙开启结果，并根据具体情况对蓝牙进行处理

 @Override

 protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        switch (requestCode) {

        case ConstantsUtil.ENABLE_BLUETOOTH:

            if (resultCode == Activity.RESULT_OK) {

               bluetoothProcess(PSystem.isServer);

            } else {

               finish();

            }

        }

     }

 public void bluetoothProcess(boolean isServer) {
     BlueToothService.getInstance().setsHandler(mHandler);
     if (isServer) {
         //如果是蓝牙服务器，则需要开启发现服务，并启动蓝牙服务器
         if(btAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
             Intent discoverableIntent = new Intent(
                 BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
             discoverableIntent.putExtra(
                 BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 180);
             startActivity(discoverableIntent);
         }
         BlueToothService.getInstance().start();
     } else {
         //如果是蓝牙客户端则扫描周围可用的蓝牙设备
         blueToothNames = new ArrayList<String>();
         blutToothDevices = new ArrayList<BluetoothDevice>();
         //添加过滤器，并注册广播，用于监听蓝牙发现信息
         IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
         this.registerReceiver(mReceiver, filter);
         filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
         this.registerReceiver(mReceiver, filter);
         //开始扫描
         doDiscovery();
     }
 }
 public void doDiscovery() {
     if (btAdapter.isDiscovering()) {
     btAdapter.cancelDiscovery();
     }
     btAdapter.startDiscovery();
  }

 

3 蓝牙广播接收器

 private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
             String action = intent.getAction();
             if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                 BluetoothDevice device = intent
                         .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                 if(device.getName() != null && !device.getName().trim().equals("")) {
                     blueToothNames.add(device.getName());
                     blutToothDevices.add(device);
                 }
             } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED
                     .equals(action)) {
                 btAdapter.cancelDiscovery();
                 TestActivity.this.unregisterReceiver(this);
             }
         }
     };

4 以上是蓝牙基本配置和发现。现在进行蓝牙监听和连接：

蓝牙服务器监听代码：

 public void start() {
         BluetoothServerSocket serverSocket = null;
         try {
             serverSocket = btAdapter.listenUsingRfcommWithServiceRecord("JumpForMeApp", MY_UUID_SECURE);
             changeState(ConstantsUtil.BT_STATE_LISTEN);
             btSocket = serverSocket.accept();
         } catch (IOException e) {
         } finally {
             try {
                 serverSocket.close();
             } catch (IOException e) {
             }
         }
         if(btSocket != null) {
             changeState(ConstantsUtil.BT_STATE_CONNECTED);
         }
     }

客户端连接代码：

 public void connect(BluetoothDevice device) {
         try {
             btAdapter.cancelDiscovery();
             btSocket = device.createRfcommSocketToServiceRecord(MY_UUID_SECURE);
             changeState(ConstantsUtil.BT_STATE_CONNECTING);
             btSocket.connect();
         } catch (IOException e) {
         }
         changeState(ConstantsUtil.BT_STATE_CONNECTED);
     }

5 利用蓝牙进行消息传递，建立新的线程来处理读写操作(见BluetoothChat Sample中的ConnectedThread)：
 

 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;
             try {
                 tmpIn = socket.getInputStream();
                 tmpOut = socket.getOutputStream();
             } catch (IOException e) {
                 Log.e(TAG, "temp sockets not created", e);
             }
             mmInStream = tmpIn;
             mmOutStream = tmpOut;
         }

         public void run() {
             byte[] buffer = new byte[1024];
             int bytes;
             while (true) {
                 try {
                     bytes = mmInStream.read(buffer);
                     if(transHandler != null) {
                         //通知数据传输处理器
                         transHandler.sendMessage(transHandler.obtainMessage(ConstantsUtil.BT_READ, bytes, -1, buffer));
                     }
                 } catch (IOException e) {
                     Log.e(TAG, "disconnected", e);
                     break;
                 }
             }
         }

         public void write(byte[] buffer) {
             try {
                 mmOutStream.write(buffer);
             } catch (IOException e) {
                 Log.e(TAG, "Exception during write", e);
             }
         }

         public void cancel() {
             try {
                 mmSocket.close();
             } catch (IOException e) {
                 Log.e(TAG, "close() of connect socket failed", e);
             }
         }
     }