Android实现主动连接蓝牙耳机

在Android程序中可以实现自动扫描蓝牙、配对蓝牙、建立数据通道。
蓝牙分不同类型，可以参考（http://gqdy365.iteye.com/admin/blogs/2229304）
可以入下面方法获取蓝牙设备支持的类型：

BluetoothDevice device;
Arrays.toString(device.getUuids());

我的蓝牙音箱支持的类型有：

0000111e-0000-1000-8000-00805f9b34fb：Handsfree
0000110b-0000-1000-8000-00805f9b34fb：AudioSink
0000110e-0000-1000-8000-00805f9b34fb：AVRemoteControl
00001203-0000-1000-8000-00805f9b34fb：GenericFileTransfer

这篇文字只讨论如何与蓝牙耳机（蓝牙音箱）连接。
蓝牙耳机一般都支持A2DP（蓝牙立体声，用于音乐播放）、HFP协议（通话），参考：http://gqdy365.iteye.com/admin/blogs/2231553
所以下面操作要同时操作A2DP和HFP，两个都连接成功，才算连接成功；

一、A2DP的操作可以分三步：

1、扫描蓝牙设备：
注册并监听广播：

BluetoothAdapter.ACTION_DISCOVERY_STARTED
BluetoothDevice.ACTION_FOUND
BluetoothAdapter.ACTION_DISCOVERY_FINISHED

启动扫描：

BluetoothAdapter.getDefaultAdapter().startDiscovery();

对扫描的结果按类型进行筛选，只保留我们需要的蓝牙耳机：

        if(device.getBluetoothClass().getDeviceClass() == BluetoothClass.Device.AUDIO_VIDEO_WEARABLE_HEADSET
                || device.getBluetoothClass().getDeviceClass() == BluetoothClass.Device.AUDIO_VIDEO_HANDSFREE){
//蓝牙耳机
}

2、配对指定的蓝牙设备：
这个跟配对普通蓝牙一样，方法如下：

public static  boolean createBond(BluetoothDevice btDevice){
    boolean result = false;
    try{
        Method m = btDevice.getClass().getDeclaredMethod("createBond",new Class[]{});
        m.setAccessible(true);
        Boolean originalResult = (Boolean) m.invoke(btDevice);
        result = originalResult.booleanValue();
    }catch(Exception ex){
    }
    return result;
}

等配对完成之后就是要建立数据连接；

3、建立数据连接：

if you SDK between 11 and 16.call a2dp.connectSink(btDevice) or a2dp.connect(btDevice)

private static IBluetoothA2dp getIBluetoothA2dp() {
    IBluetoothA2dp ibta = null;

    try {
        final Class serviceManager = Class.forName("android.os.ServiceManager");
        final Method getService = serviceManager.getDeclaredMethod("getService", String.class);
        final IBinder iBinder = (IBinder) getService.invoke(null, "bluetooth_a2dp");
        final Class iBluetoothA2dp = Class.forName("android.bluetooth.IBluetoothA2dp");
        final Class[] declaredClasses = iBluetoothA2dp.getDeclaredClasses();
        final Class c = declaredClasses[0];
        final Method asInterface = c.getDeclaredMethod("asInterface", IBinder.class);

        asInterface.setAccessible(true);
        ibta = (IBluetoothA2dp) asInterface.invoke(null, iBinder);
    } catch (final Exception e) {
        Log.e("Error " + e.getMessage());
    }
    return ibta;
}

参考：http://stackoverflow.com/questions/8467178/working-around-a2dp-and-hfp-limitations-of-android-pre-honeycomb

如果API大于16需要用如下的方法：

    private void initA2dpService(){
//      Intent i = getExplicitIntent(mContext,new Intent(IBluetoothA2dp.class.getName()));//5.0以上系统需要显示intent
//详细参考http://blog.csdn.net/l2show/article/details/47421961
        Intent i = new Intent(IBluetoothA2dp.class.getName());
        boolean success = mContext.bindService(i, mConnection, Context.BIND_AUTO_CREATE);
        if (success) {

        } else {
        }
    }

    public ServiceConnection mConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            try {
                mA2dpService = IBluetoothA2dp.Stub.asInterface(service);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            // TODO Auto-generated method stub

        }

    };

    public Intent getExplicitIntent(Context context, Intent implicitIntent) {
        // Retrieve all services that can match the given intent
        PackageManager pm = context.getPackageManager();
        List<ResolveInfo> resolveInfo = pm.queryIntentServices(implicitIntent, 0);
        // Make sure only one match was found
        if (resolveInfo == null || resolveInfo.size() != 1) {
            return null;
        }
        // Get component info and create ComponentName
        ResolveInfo serviceInfo = resolveInfo.get(0);
        String packageName = serviceInfo.serviceInfo.packageName;
        String className = serviceInfo.serviceInfo.name;
        ComponentName component = new ComponentName(packageName, className);
        // Create a new intent. Use the old one for extras and such reuse
        Intent explicitIntent = new Intent(implicitIntent);
        // Set the component to be explicit
        explicitIntent.setComponent(component);
        return explicitIntent;
    }

建立连接：mA2dpService.connect(device);
断开连接：mA2dpService.disconnect(device);

参考：http://stackoverflow.com/questions/14705167/how-connect-paired-bluetooth-a2dp-device-on-android-4-2-using-reflection

http://blog.csdn.net/qs_csu/article/details/45114251

二、HFP操作：
下面只针对4.0及以上版本；
1、初始化：

private void initOrCloseBtCheck(boolean init){
    if(init){
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        mBluetoothAdapter.getProfileProxy(mContext, new ServiceListener() {
            public void onServiceConnected(int profile, BluetoothProfile proxy) {
                if (profile == BluetoothProfile.HEADSET) {
                    mBluetoothHeadset = (BluetoothHeadset) proxy;
                }
            }

            public void onServiceDisconnected(int profile) {
                if (profile == BluetoothProfile.HEADSET) {
                    mBluetoothHeadset = null;
                }
            }
        },BluetoothProfile.HEADSET);
    }else{
        mBluetoothAdapter.closeProfileProxy(BluetoothProfile.HEADSET,mBluetoothHeadset);
    }
}

建立连接：

         Method m = mBluetoothHeadset.getClass().getDeclaredMethod("connect",BluetoothDevice.class);
m.setAccessible(true);
//连接Headset
boolean successHeadset = (Boolean)m.invoke(mBluetoothHeadset, device);

断开连接：

         Method m = mBluetoothHeadset.getClass().getDeclaredMethod("disconnect",BluetoothDevice.class);
m.setAccessible(true);
m.invoke(mBluetoothHeadset, device);

三、状态判断：

蓝牙耳机连接成功：

mA2dpService.getConnectionState(device) == BluetoothA2dp.STATE_DISCONNECTED && mBluetoothHeadset.getConnectionState(device) == BluetoothProfile.STATE_DISCONNECTED

断开成功：

(mA2dpService.getConnectionState(device) == BluetoothA2dp.STATE_CONNECTED || mA2dpService.getConnectionState(device) == BluetoothA2dp.STATE_PLAYING)
                                && mBluetoothHeadset.getConnectionState(device) == BluetoothProfile.STATE_CONNECTED