Android蓝牙通信

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    Android为蓝牙设备之间的通信封装好了一些调用接口,使得实现Android的蓝牙通信功能并不困难。可通过UUID使两个设备直接建立连接。

   具体步骤:

    1.  获取BluetoothAdapter实例,注册一个BroadcastReceiver监听蓝牙扫描过程中的状态变化

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);registerReceiver(mReceiver, filter);
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            String action = intent.getAction();            // When discovery finds a device            if (BluetoothDevice.ACTION_FOUND.equals(action))             {                // Get the BluetoothDevice object from the Intent            // 通过EXTRA_DEVICE附加域来得到一个BluetoothDevice设备                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);                                // If it's already paired, skip it, because it's been listed already                // 如果这个设备是不曾配对过的,添加到list列表                if (device.getBondState() != BluetoothDevice.BOND_BONDED)                 {                list.add(new ChatMessage(device.getName() + "\n" + device.getAddress(), false));                clientAdapter.notifyDataSetChanged();            mListView.setSelection(list.size() - 1);                }            // When discovery is finished, change the Activity title            }             else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action))             {                setProgressBarIndeterminateVisibility(false);                if (mListView.getCount() == 0)                 {                list.add(new ChatMessage("没有发现蓝牙设备", false));                clientAdapter.notifyDataSetChanged();            mListView.setSelection(list.size() - 1);                }            }        }    };

    2.  打开蓝牙(enable),并设置蓝牙的可见性(可以被其它设备扫描到,客户端是主动发请求的,可不设置,服务端必须设置可见)。

               if (mBluetoothAdapter != null) {if (!mBluetoothAdapter.isEnabled()) {// 发送打开蓝牙的意图,系统会弹出一个提示对话框        Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);        startActivityForResult(enableIntent, RESULT_FIRST_USER);                // 设置蓝牙的可见性,最大值3600秒,默认120秒,0表示永远可见(作为客户端,可见性可以不设置,服务端必须要设置)        Intent displayIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);        displayIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 0);        startActivity(displayIntent);                // 直接打开蓝牙        mBluetoothAdapter.enable();}}

    3.  扫描,startDiscovery()方法是一个很耗性能的操作,在扫描之前可以先使用getBondedDevices()获取已经配对过的设备(可直接连接),避免不必要的消耗。

      private void scanDevice() {// TODO Auto-generated method stub    if (mBluetoothAdapter.isDiscovering()) {mBluetoothAdapter.cancelDiscovery();} else {// 每次扫描前都先判断一下是否存在已经配对过的设备    Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();    if (pairedDevices.size() > 0) {        for (BluetoothDevice device : pairedDevices) {            list.add(new ChatMessage(device.getName() + "\n" + device.getAddress(), true));        }    } else {        list.add(new ChatMessage("No devices have been paired", true));        clientAdapter.notifyDataSetChanged();    mListView.setSelection(list.size() - 1);     }             /* 开始搜索 */             mBluetoothAdapter.startDiscovery();}}

    4.  通过Mac地址发送连接请求,在这之前必须使用cancelDiscovery()方法停止扫描。

                mBluetoothAdapter.cancelDiscovery();// 通过Mac地址去尝试连接一个设备BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(BluetoothMsg.BlueToothAddress);

    5.  通过UUID使两个设备之间建立连接。

         客户端:主动发请求

     BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));     // 通过socket连接服务器,这是一个阻塞过程,直到连接建立或者连接失效     socket.connect();

        服务端:接受一个请求        

     BluetoothServerSocket mServerSocket = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(PROTOCOL_SCHEME_RFCOMM,UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));     /* 接受客户端的连接请求 */     // 这是一个阻塞过程,直到建立一个连接或者连接失效     // 通过BluetoothServerSocket得到一个BluetoothSocket对象,管理这个连接     BluetoothSocket socket = mServerSocket.accept();

    6.  通过InputStream/outputStream读写数据流,已达到通信目的。

     OutputStream os = socket.getOutputStream();     os.write(msg.getBytes());
     InputStream is = null;     try {         is = socket.getInputStream();     } catch (IOException e) {         // TODO Auto-generated catch block         e.printStackTrace();     }

    7.  关闭所有线程以及socket,并关闭蓝牙设备(disable)。

     

                        if (mClientThread != null) {    mClientThread.interrupt();    mClientThread = null;}    if (mReadThread != null) {mReadThread.interrupt();mReadThread = null;}    try {if (socket != null) {socket.close();socket = null;}} catch (IOException e) {// TODO: handle exception}
                if (mBluetoothAdapter != null) {mBluetoothAdapter.cancelDiscovery();// 关闭蓝牙mBluetoothAdapter.disable();}unregisterReceiver(mReceiver);

主要步骤就是这些,为了能够更好的理解,我将服务器端和客户端的代码分开来写了两个程序,下载地址:http://download.csdn.net/detail/visionliao/8417235
  


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