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);
			}
		}
	}