android蓝牙通信

 

一 蓝牙开启

首先需要获取系统的蓝牙适配器，如果适配器不为空且没有开启的话，通过intent进行开启操作，相关代码如下：

BluetoothAdapter blueadapter = BluetoothAdapter.getDefaultAdapter();

if (blueadapter != null) {  //Device support Bluetooth
    //确认开启蓝牙
    if (!blueadapter.isEnabled()) {
        //请求用户开启
        Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(intent, RESULT_FIRST_USER);
        //使蓝牙设备可见，方便配对
        Intent in = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        in.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 200);
        startActivity(in);
        //直接开启，不经过提示
   //     blueadapter.enable();
    }
} 

 

二   设备搜索

主动发起搜索：

blueadapter.startDiscovery()

获取配对过的蓝牙设备：

Set<BluetoothDevice> device = blueadapter.getBondedDevices();
data.clear();
if (blueadapter != null && blueadapter.isDiscovering()) {

    adapter.notifyDataSetChanged();
}
if (device.size() > 0) { //存在已经配对过的蓝牙设备
    for (Iterator<BluetoothDevice> it = device.iterator(); it.hasNext(); ) {
        BluetoothDevice btd = it.next();
        blueadapter.getProfileConnectionState(BluetoothProfile.A2DP);
        data.add(btd);
    }
} else {  //不存在已经配对过的蓝牙设备
}

需要注意的是服务端的蓝牙设备类型要与BluetoothProfile.A2DP统一

三  状态监听

首先先注册广播：

IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
filter.addAction(ACTION_STATE_CHANGED);
filter.addAction(ACTION_DISCOVERY_FINISHED);
registerReceiver(receiver, filter);

编写广播类：

private DeviceReceiver receiver = new DeviceReceiver();

private class DeviceReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        Logd("-----------DeviceReceiver:"+action);
        if (BluetoothDevice.ACTION_FOUND.equals(action)) {    //搜索到新设备
           // data.clear();
            BluetoothDevice btd = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            //搜索没有配过对的蓝牙设备
            if (btd.getBondState() != BluetoothDevice.BOND_BONDED) {
                data.add(btd);
                adapter.notifyDataSetChanged();
            }
        } else if (ACTION_DISCOVERY_FINISHED.equals(action)) {   //搜索结束

            if (binding.listview.getCount() == 0) {
                adapter.notifyDataSetChanged();
            }
        }
        else if (action.equals(ACTION_STATE_CHANGED)) {
            int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,
                    BluetoothAdapter.ERROR);
            switch (state) {
                case BluetoothAdapter.STATE_OFF:
                    Log.d("aaa", "STATE_OFF 手机蓝牙关闭");
                    binding.tvState.setText(R.string.tip_bluetooth_close);
                    break;
                case BluetoothAdapter.STATE_TURNING_OFF:
                    Log.d("aaa", "STATE_TURNING_OFF 手机蓝牙正在关闭");
                    break;
                case BluetoothAdapter.STATE_ON:
                    Log.d("aaa", "STATE_ON 手机蓝牙开启");
                    binding.tvState.setText(R.string.tip_bluetooth_open);
                    search(null);
                    break;
                case BluetoothAdapter.STATE_TURNING_ON:
                    Log.d("aaa", "STATE_TURNING_ON 手机蓝牙正在开启");
                    findAvalibleDevice();
                    break;
            }
        }
    }
}

 

四  蓝牙通信

服务端

蓝牙Server端就是通过线程来注册一个具有名称和唯一识别的UUID号的BluetoothServerSocket, 然后就一直监听Client端(BluetoothSocket)的请求，并对这些请求做出相应的处理。

// 注册蓝牙Server

    /* 创建一个蓝牙服务器
     * 参数分别：服务器名称、UUID   */
mserverSocket = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(PROTOCOL_SCHEME_RFCOMM,
        UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));

 

参数PROTOCOL_SCHEME_RFCOMM是一个String类型的常量，表示蓝牙Server的名称，而UUID.fromString()表示蓝牙Server的唯一标识UUID。

在Client连接到Server时需要使用该UUID号。

// 接收Client的连接请求

socket = mserverSocket.accept();

// 处理接收内容

//读取数据
private class readThread extends Thread {
    @Override
    public void run() {

        byte[] buffer = new byte[1024];
        int bytes;
        InputStream mmInStream = null;

        try {
            mmInStream = socket.getInputStream();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        while (true) {
            try {
                // Read from the InputStream
                if( (bytes = mmInStream.read(buffer)) > 0 )
                {
                    byte[] buf_data = new byte[bytes];
                    for(int i=0; i<bytes; i++)
                    {
                        buf_data[i] = buffer[i];
                    }
                    String s = new String(buf_data);
                    Message msg = new Message();
                    msg.obj = s;
                    msg.what = 1;
                    LinkDetectedHandler.sendMessage(msg);
                }
            } catch (IOException e) {
                try {
                    mmInStream.close();
                } catch (IOException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
                break;
            }
        }
    }
}

 

客户端

客户端连接时需要知道服务端的UUID号，代码如下：

socket = device.createRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
socket.connect();

发送数据

if (socket == null)
{
    Toast.makeText(mContext, "没有连接", Toast.LENGTH_SHORT).show();
    return;
}
try {
    OutputStream os = socket.getOutputStream();
    os.write(msg.getBytes());
} catch (IOException e) {
    e.printStackTrace();
}