Android蓝牙socket实现视频实时传输，以及图片和文本传输

目标
两台手机设备之间能够正常进行蓝牙配对（蓝牙模块儿和硬件挂钩，所以需要两台真机）
socket实现蓝牙文本传输
实现图片传输

实现实时视频传输

代码下载：https://download.youkuaiyun.com/download/m0_37781149/10434336

蓝牙传输注意事项
Bluetooth的MTU（最大传输单元）是20字节，即一次最多能发送20个字节，若超过20个字节，建议采用分包传输的方式。在传输图片和视频的时候处理方式是将图片转换成字节byte,并在图片前面添加一个头，加入相应的标志位，例如图片大小。然后在接受端进行整合，获取图片大小（字节长度），进行相应判断，整合成图片再显示。下面分模块儿讲解：
蓝牙扫描
 通过注册广播来获取蓝牙列表，蓝牙连接状态发生改变时候系统都会发送相应广播，获取相应的蓝牙列表并添加到list中，显示出来

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            //当发现蓝牙设备
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    String strNoFound = getIntent().getStringExtra("no_devices_found");
                    if (strNoFound == null)
                        strNoFound = "No devices found";

                    if (mPairedDevicesArrayAdapter.getItem(0).equals(strNoFound)) {
                        mPairedDevicesArrayAdapter.remove(strNoFound);
                    }
                    mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                }

            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                String strSelectDevice = getIntent().getStringExtra("select_device");
                if (strSelectDevice == null)
                    strSelectDevice = "Select a device to connect";
                setTitle(strSelectDevice);
            }
        }
    };    

    //扫描蓝牙设备
    private void doDiscovery() {
        mPairedDevicesArrayAdapter.clear();
        if (pairedDevices.size() > 0) {
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String strNoFound = getIntent().getStringExtra("no_devices_found");
            if (strNoFound == null)
                strNoFound = "No devices found";
            mPairedDevicesArrayAdapter.add(strNoFound);
        }

        String strScanning = getIntent().getStringExtra("scanning");
        if (strScanning == null)
            strScanning = "Scanning for devices...";
        setProgressBarIndeterminateVisibility(true);
        setTitle(strScanning);

        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }
        mBtAdapter.startDiscovery();
    }

点击对应的条目可以回退到MainActivity，并将对应的mac地址携带回来，用于蓝牙配对连接

    //携带蓝牙地址返回主界面
    private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            if (mBtAdapter.isDiscovering())
                mBtAdapter.cancelDiscovery();

            String strNoFound = getIntent().getStringExtra("no_devices_found");
            if (strNoFound == null)
                strNoFound = "No devices found";
            if (!((TextView) v).getText().toString().equals(strNoFound)) {
                String info = ((TextView) v).getText().toString();
                String address = info.substring(info.length() - 17);
                Intent intent = new Intent();
                intent.putExtra(BluetoothState.EXTRA_DEVICE_ADDRESS, address);
                setResult(Activity.RESULT_OK, intent);
                finish();
            }
        }
    };


蓝牙连接核心工具类BluetoothUtil,蓝牙状态BluetoothState和BluetoothService
蓝牙配对基本过程：在APP启动的时候，开启一个线程一直监听蓝牙的连接状态，这个子线程是启动时是死循环状态，在蓝牙连接成功时会停止，在蓝牙意外断开时候会重新处于监听状态
     
    public void onStart() {
        super.onStart();
        if (!mBt.isBluetoothEnabled()) {
            //打开蓝牙
            Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(intent, BluetoothState.REQUEST_ENABLE_BT);
        } else {
            if (!mBt.isServiceAvailable()) {
                //开启监听
                mBt.setupService();
                mBt.startService(BluetoothState.DEVICE_ANDROID);
            }
        }
    }

     public void setupService() {
        mChatService = new BluetoothService(mContext, mHandler);
    }

     public BluetoothService(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = BluetoothState.STATE_NONE;
        mHandler = handler;
    }

    //开启蓝牙一直监听是否连接的状态
    public void startService(boolean isAndroid) {
        if (mChatService != null) {
            if (mChatService.getState() == BluetoothState.STATE_NONE) {
                isServiceRunning = true;
                mChatService.start(isAndroid);
                BluetoothUtil.this.isAndroid = isAndroid;
            }
        }
    }

     //开启子线程
    public synchronized void start(boolean isAndroid) {
        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        setState(BluetoothState.STATE_LISTEN);
        
        //开启子线程
        if (mSecureAcceptThread == null) {
            mSecureAcceptThread = new AcceptThread(isAndroid);
            mSecureAcceptThread.start();
            BluetoothService.this.isAndroid = isAndroid;
        }
    }

    //监听蓝牙连接的线程
    private class AcceptThread extends Thread {
        private BluetoothServerSocket mmServerSocket;
        private String mSocketType;
        boolean isRunning = true;

        public AcceptThread(boolean isAndroid) {
            BluetoothServerSocket tmp = null;
            try {
                if (isAndroid)
                    //获取蓝牙socket
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_ANDROID_DEVICE);
                else
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_OTHER_DEVICE);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }

        public void run() {
            setName("AcceptThread" + mSocketType);
            BluetoothSocket socket = null;
            //死循环监听蓝牙连接状态，首次进入一定满足条件，蓝牙连上后，循环停止
            while (mState != BluetoothState.STATE_CONNECTED && isRunning) {
                try {
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }

                if (socket != null) {
                    synchronized (BluetoothService.this) {
                        switch (mState) {
                            case BluetoothState.STATE_LISTEN:
                            case BluetoothState.STATE_CONNECTING:
                                connected(socket, socket.getRemoteDevice(),
                                        mSocketType);
                                break;
                            case BluetoothState.STATE_NONE:
                            case BluetoothState.STATE_CONNECTED:
                                try {
                                    socket.close();
                                } catch (IOException e) {
                                }
                                break;
                        }
                    }
                }
            }
        }

        public void cancel() {
            try {
                mmServerSocket.close();
                mmServerSocket = null;
            } catch (IOException e) {
            }
        }

        public void kill() {
            isRunning = false;
        }
    }

核心部分：蓝牙发送和接受数据，蓝牙发送数据处理过程，比如发送一张图片，肯定是大于20字节的，蓝牙是采用分包发送机制，在处理的时候，我们把图片转换成字节，并在图片前面添加一个头，这个头是固定字节的长度，不能太小，因为拍摄图片的时候，图片有大有小，避免和图面装换成字节后产生冲突。这个头里面主要携带两个信息，当然也可以是多个，自由定义。两个信息分别是，图片的大小，即字节长度length，还有一个是动作，例如传照片，传文本，实时视频传输，代码如下：

    //添加头发送数据
    public void send(byte[] data, String str) {
        int length = data.length;
        byte[] length_b = null;
        try {
            length_b = intToByteArray(length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (length_b == null) return;

        //获得一个字节长度为14的byte数组 headInfoLength为14
        byte[] headerInfo = new byte[headInfoLength];

        //前六位添加012345的标志位
        for (int i = 0; i < headInfoLength - 8; i++) {
            headerInfo[i] = (byte) i;
        }
        
        //7到10位添加图片大小的字节长度
        for (int i = 0; i < 4; i++) {
            headerInfo[6 + i] = length_b[i];
        }
        
        //11到14位添加动作信息
        if (str.equals("text")) {
            for (int i = 0; i < 4; i++) {
                headerInfo[10 + i] = (byte) 0;
            }
        } else if (str.equals("photo")) {
            for (int i = 0; i < 4; i++) {
                headerInfo[10 + i] = (byte) 1;
            }
        } else if (str.equals("video")) {
            for (int i = 0; i < 4; i++) {
                headerInfo[10 + i] = (byte) 2;
            }
        } 

        //将对应信息添加到图片前面
        byte[] sendMsg = new byte[length + headInfoLength];
        for (int i = 0; i < sendMsg.length; i++) {
            if (i < headInfoLength) {
                sendMsg[i] = headerInfo[i];
            } else {
                sendMsg[i] = data[i - headInfoLength];
            }

        }
        mChatService.write(sendMsg);
    }
    
    //蓝牙socket发送数据
     public void write(byte[] out) {
        ConnectedThread r;
        synchronized (this) {
            if (mState != BluetoothState.STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        r.write(out);
    }

      public void write(byte[] buffer) {
            try {
                mmOutStream.write(buffer);
            } catch (IOException e) {
            }
        }

蓝牙接收数据：接收到的数据都是字节数据，我们需要把数据进行整合成对应的图片或视频信息，因为发送时分包机制，所以整合的时候要确保整张图片发送完毕才开始整合，具体流程是先获取前六位标志位，然后获取第7到10位的图片大小，再获取第11位到14位的动作信息，具体代码如下：
     
        public void run() {
            byte[] buffer;
            ArrayList<Integer> arr_byte = new ArrayList<Integer>();
            while (true) {
                try {
                    boolean valid = true;
                    //判断前六位是不是012345
                    for (int i = 0; i < 6; i++) {
                        int t = mmInStream.read();
                        if (t != i) {
                            valid = false;
                            //前六位判断完了跳出循环
                            break;
                        }
                    }
                    if (valid) {
                        //获取图片大小
                        byte[] bufLength = new byte[4];
                        for (int i = 0; i < 4; i++) {
                            bufLength[i] = ((Integer) mmInStream.read()).byteValue();
                        }
                
                        int TextCount = 0;
                        int PhotoCount = 0;
                        int VideoCount = 0;
                        //获取动作信息
                        for (int i = 0; i < 4; i++) {
                            int read = mmInStream.read();
                            if (read == 0) {
                                TextCount++;
                            } else if (read == 1) {
                                PhotoCount++;
                            } else if (read == 2) {
                                VideoCount++;
                            }
                        }

                        //获取图片的字节
                        int length = ByteArrayToInt(bufLength);
                        buffer = new byte[length];
                        for (int i = 0; i < length; i++) {
                            buffer[i] = ((Integer) mmInStream.read()).byteValue();
                        }
            
                        //通过handler发出去
                        Message msg = Message.obtain();
                        msg.what = BluetoothState.MESSAGE_READ;
                        msg.obj = buffer;

                        if (TextCount == 4) {
                            msg.arg1 = 0;
                            mHandler.sendMessage(msg);
                        } else if (PhotoCount == 4) {
                            msg.arg1 = 1;
                            mHandler.sendMessage(msg);
                        } else if (VideoCount == 4) {
                            msg.arg1 = 2;
                            mHandler.sendMessage(msg);
                        }

                    }

                } catch (IOException e) {
                    connectionLost();
                    BluetoothService.this.start(BluetoothService.this.isAndroid);
                    break;
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

        }

下面分别是发送端和接受端的完整代码：
发送端SendClient代码部分：
layout文件：

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.rejointech.sendclient.MainActivity">

    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="match_parent"
        android:layout_height="300dp"/>

    <EditText
        android:layout_marginTop="20dp"
        android:id="@+id/input"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入要发送的文本信息"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:orientation="horizontal">

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="bluetooth"
            android:text="蓝牙"
            android:textColor="#000"
            android:textSize="18sp"/>

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="文本"
            android:onClick="sendText"
            android:textColor="#000"
            android:textSize="18sp"/>

        <Button
            android:onClick="sendPhoto"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="图片"
            android:textColor="#000"
            android:textSize="18sp"/>

        <Button
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="视频"
            android:onClick="sendVideo"
            android:textColor="#000"
            android:textSize="18sp"/>
    </LinearLayout>
</LinearLayout>

发射端的主界面:

    public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback {
    private static final String TAG = MainActivity.class.getName();
    private static final int REQUEST_BLUETOOTH_ENABLE = 100;
    private BluetoothUtil mBt;
    private Camera mCamera;
    private SurfaceHolder mSurfaceHolder;
    private int mWidth;
    private int mHeight;
    private EditText mInput;
    private boolean isBluetoothConnnect;
    public Camera.Size size;
    private boolean mark = true;
    private int count;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mBt = new BluetoothUtil(this);
        mInput = (EditText) findViewById(R.id.input);
        SurfaceView surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
        mSurfaceHolder = surfaceView.getHolder();
        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        mSurfaceHolder.addCallback(this);
        initBlue();
    }

    private void initBlue() {
        /**
         * reveice data
         */
        mBt.setOnDataReceivedListener(new BluetoothUtil.OnDataReceivedListener() {
            public void onDataReceived(byte[] data, String message) {

            }
        });

        mBt.setBluetoothConnectionListener(new BluetoothUtil.BluetoothConnectionListener() {
            public void onDeviceConnected(String name, String address) {
                isBluetoothConnnect = true;
                Toast.makeText(getApplicationContext(), "连接到 " + name + "\n" + address, Toast.LENGTH_SHORT).show();
            }

            public void onDeviceDisconnected() {
                isBluetoothConnnect = false;
                //断开蓝牙连接
                Toast.makeText(getApplicationContext(), "蓝牙断开", Toast.LENGTH_SHORT).show();

            }

            public void onDeviceConnectionFailed() {
                Toast.makeText(getApplicationContext(), "无法连接", Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == BluetoothState.REQUEST_CONNECT_DEVICE) {
            if (resultCode == Activity.RESULT_OK)
                mBt.connect(data);
        } else if (requestCode == BluetoothState.REQUEST_ENABLE_BT) {
            if (resultCode == Activity.RESULT_OK) {
                mBt.setupService();
                mBt.startService(BluetoothState.DEVICE_ANDROID);
            } else {
                finish();
            }
        }
    }

    public void onStart() {
        super.onStart();
        if (!mBt.isBluetoothEnabled()) {
            //打开蓝牙
            Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(intent, BluetoothState.REQUEST_ENABLE_BT);
        } else {
            if (!mBt.isServiceAvailable()) {
                //开启监听
                mBt.setupService();
                mBt.startService(BluetoothState.DEVICE_ANDROID);
            }
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mBt.stopService();
        releaseCamera();
    }

    private void releaseCamera() {
        if (mCamera != null) {
            mCamera.setPreviewCallback(null);
            mCamera.setPreviewCallbackWithBuffer(null);
            mCamera.stopPreview();// 停掉原来摄像头的预览
            mCamera.release();
            mCamera = null;
        }
    }


    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            mCamera = Camera.open();
            Camera.Parameters mPara = mCamera.getParameters();
            List<Camera.Size> pictureSizes = mCamera.getParameters().getSupportedPictureSizes();
            List<Camera.Size> previewSizes = mCamera.getParameters().getSupportedPreviewSizes();

            int previewSizeIndex = -1;
            Camera.Size psize;
            int height_sm = 999999;
            int width_sm = 999999;
            //获取设备最小分辨率图片，图片越清晰，传输越卡
            for (int i = 0; i < previewSizes.size(); i++) {
                psize = previewSizes.get(i);
                if (psize.height <= height_sm && psize.width <= width_sm) {
                    previewSizeIndex = i;
                    height_sm = psize.height;
                    width_sm = psize.width;
                }
            }

            if (previewSizeIndex != -1) {
                mWidth = previewSizes.get(previewSizeIndex).width;
                mHeight = previewSizes.get(previewSizeIndex).height;
                mPara.setPreviewSize(mWidth, mHeight);
            }
            mCamera.setParameters(mPara);
            mCamera.setPreviewDisplay(mSurfaceHolder);
            mCamera.startPreview();

            size = mCamera.getParameters().getPreviewSize();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {

    }

    //蓝牙搜索配对
    public void bluetooth(View view) {
        if (mBt.getServiceState() == BluetoothState.STATE_CONNECTED) {
            mBt.disconnect();
        } else {
            Intent intent = new Intent(getApplicationContext(), BluetoothActivity.class);
            startActivityForResult(intent, BluetoothState.REQUEST_CONNECT_DEVICE);
        }
    }

    //发送文本信息
    public void sendText(View view) {
        if (!isBluetoothConnnect) {
            Toast.makeText(this, "请连接蓝牙", Toast.LENGTH_SHORT).show();
            return;
        }
        String input = mInput.getText().toString().trim();
        if (input != null && !input.isEmpty()) {
            mBt.send(input.getBytes(), "TEXT");
        } else {
            Toast.makeText(MainActivity.this, "输入信息不能为空", Toast.LENGTH_SHORT).show();
        }

    }

    //发送图片
    public void sendPhoto(View view) {
        if (!isBluetoothConnnect) {
            Toast.makeText(this, "请连接蓝牙", Toast.LENGTH_SHORT).show();
            return;
        }
        mark = false;//关闭视频发送
        mCamera.takePicture(null, null, new Camera.PictureCallback() {
            @Override
            public void onPictureTaken(byte[] bytes, Camera camera) {
                mBt.send(bytes, "photo");
                mCamera.startPreview();
            }
        });
    }

    //发送视频 其实也是发送一张一张的图片
    public void sendVideo(View view) {
        if (!isBluetoothConnnect) {
            Toast.makeText(this, "请连接蓝牙", Toast.LENGTH_SHORT).show();
            return;
        }
        mark = true;
        new Thread(new Runnable() {
            @Override
            public void run() {
                mCamera.setPreviewCallback(new Camera.PreviewCallback() {
                    @Override
                    public void onPreviewFrame(byte[] data, Camera camera) {
                        count++;
                        Camera.Size size = camera.getParameters().getPreviewSize();
                        final YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);
                        ByteArrayOutputStream stream = new ByteArrayOutputStream();
                        image.compressToJpeg(new Rect(0, 0, mWidth, mHeight), 100, stream);
                        byte[] imageBytes = stream.toByteArray();
                        if (count % 2 == 0 && mark) {
                            mBt.send(imageBytes, "video");
                        }
                    }
                });
            }
        }).start();
    }
    }

蓝牙列表的页面

    public class BluetoothActivity extends AppCompatActivity {
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter<String> mPairedDevicesArrayAdapter;
    private Set<BluetoothDevice> pairedDevices;
    private Button scanButton;
    private SharedPreferences mSp;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        int listId = getIntent().getIntExtra("layout_list", R.layout.device_list);
        setContentView(listId);
        String strBluetoothDevices = getIntent().getStringExtra("bluetooth_devices");
        if (strBluetoothDevices == null)
            strBluetoothDevices = "Bluetooth Devices";
        setTitle(strBluetoothDevices);
        setResult(Activity.RESULT_CANCELED);
        scanButton = (Button) findViewById(R.id.button_scan);
        String strScanDevice = getIntent().getStringExtra("scan_for_devices");
        if (strScanDevice == null)
            strScanDevice = "SCAN FOR DEVICES";
        scanButton.setText("搜索");
        scanButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                doDiscovery();
            }
        });

        int layout_text = getIntent().getIntExtra("layout_text", R.layout.device_name);
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, layout_text);

        ListView pairedListView = (ListView) findViewById(R.id.list_devices);
        pairedListView.setAdapter(mPairedDevicesArrayAdapter);
        pairedListView.setOnItemClickListener(mDeviceClickListener);
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        this.registerReceiver(mReceiver, filter);

        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(mReceiver, filter);
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();
        pairedDevices = mBtAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String noDevices = "No devices found";
            mPairedDevicesArrayAdapter.add(noDevices);
        }
    }

    @Override
    protected void onStart() {
        super.onStart();

    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            //当发现蓝牙设备
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    String strNoFound = getIntent().getStringExtra("no_devices_found");
                    if (strNoFound == null)
                        strNoFound = "No devices found";

                    if (mPairedDevicesArrayAdapter.getItem(0).equals(strNoFound)) {
                        mPairedDevicesArrayAdapter.remove(strNoFound);
                    }
                    mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
                }

            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                String strSelectDevice = getIntent().getStringExtra("select_device");
                if (strSelectDevice == null)
                    strSelectDevice = "Select a device to connect";
                setTitle(strSelectDevice);
            }
        }
    };

    //携带蓝牙地址返回主界面
    private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            if (mBtAdapter.isDiscovering())
                mBtAdapter.cancelDiscovery();

            String strNoFound = getIntent().getStringExtra("no_devices_found");
            if (strNoFound == null)
                strNoFound = "No devices found";
            if (!((TextView) v).getText().toString().equals(strNoFound)) {
                String info = ((TextView) v).getText().toString();
                String address = info.substring(info.length() - 17);
                Intent intent = new Intent();
                intent.putExtra(BluetoothState.EXTRA_DEVICE_ADDRESS, address);
                setResult(Activity.RESULT_OK, intent);
                finish();
            }
        }
    };

    //扫描蓝牙设备
    private void doDiscovery() {
        mPairedDevicesArrayAdapter.clear();
        if (pairedDevices.size() > 0) {
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        } else {
            String strNoFound = getIntent().getStringExtra("no_devices_found");
            if (strNoFound == null)
                strNoFound = "No devices found";
            mPairedDevicesArrayAdapter.add(strNoFound);
        }

        String strScanning = getIntent().getStringExtra("scanning");
        if (strScanning == null)
            strScanning = "Scanning for devices...";
        setProgressBarIndeterminateVisibility(true);
        setTitle(strScanning);

        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }
        mBtAdapter.startDiscovery();
    }

    protected void onDestroy() {
        super.onDestroy();
        if (mBtAdapter != null) {
            mBtAdapter.cancelDiscovery();
        }
        this.unregisterReceiver(mReceiver);
        this.finish();
    }

BluetoothUtil工具类

    public class BluetoothUtil {
    private BluetoothStateListener mBluetoothStateListener = null;
    private OnDataReceivedListener mDataReceivedListener = null;
    private BluetoothConnectionListener mBluetoothConnectionListener = null;
    private AutoConnectionListener mAutoConnectionListener = null;
    private Context mContext;
    private BluetoothAdapter mBluetoothAdapter = null;
    private BluetoothService mChatService = null;
    private String mDeviceName = null;
    private String mDeviceAddress = null;
    private boolean isAutoConnecting = false;
    private boolean isAutoConnectionEnabled = false;
    private boolean isConnected = false;
    private boolean isConnecting = false;
    private boolean isServiceRunning = false;
    private String keyword = "";
    private boolean isAndroid = BluetoothState.DEVICE_ANDROID;
    private BluetoothConnectionListener bcl;
    private int c = 0;
    private static int headInfoLength = 10;

    //获取蓝牙adapter
    public BluetoothUtil(Context context) {
        mContext = context;
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    }

    //判断蓝牙是否可用
    public boolean isBluetoothEnable() {
        return mBluetoothAdapter.isEnabled();
    }

    public interface BluetoothStateListener {
        public void onServiceStateChanged(int state);
    }

    public interface OnDataReceivedListener {
        public void onDataReceived(byte[] data, String message);
    }

    public interface BluetoothConnectionListener {
        public void onDeviceConnected(String name, String address);
        public void onDeviceDisconnected();
        public void onDeviceConnectionFailed();
    }

    public interface AutoConnectionListener {
        public void onAutoConnectionStarted();
        public void onNewConnection(String name, String address);
    }

    public boolean isBluetoothAvailable() {
        try {
            if (mBluetoothAdapter == null || mBluetoothAdapter.getAddress().equals(null))
                return false;
        } catch (NullPointerException e) {
            return false;
        }
        return true;
    }

    public boolean isBluetoothEnabled() {
        return mBluetoothAdapter.isEnabled();
    }

    public boolean isServiceAvailable() {
        return mChatService != null;
    }

    public boolean isAutoConnecting() {
        return isAutoConnecting;
    }

    public boolean startDiscovery() {
        return mBluetoothAdapter.startDiscovery();
    }

    public boolean isDiscovery() {
        return mBluetoothAdapter.isDiscovering();
    }

    public boolean cancelDiscovery() {
        return mBluetoothAdapter.cancelDiscovery();
    }

    public void setupService() {
        mChatService = new BluetoothService(mContext, mHandler);
    }

    public BluetoothAdapter getBluetoothAdapter() {
        return mBluetoothAdapter;
    }

    public int getServiceState() {
        if(mChatService != null)
            return mChatService.getState();
        else
            return -1;
    }

    //开启蓝牙一直监听是否连接的状态
    public void startService(boolean isAndroid) {
        if (mChatService != null) {
            if (mChatService.getState() == BluetoothState.STATE_NONE) {
                isServiceRunning = true;
                mChatService.start(isAndroid);
                BluetoothUtil.this.isAndroid = isAndroid;
            }
        }
    }

    public void stopService() {
        if (mChatService != null) {
            isServiceRunning = false;
            mChatService.stop();
        }
        new Handler().postDelayed(new Runnable() {
            public void run() {
                if (mChatService != null) {
                    isServiceRunning = false;
                    mChatService.stop();
                }
            }
        }, 500);
    }

    public void setDeviceTarget(boolean isAndroid) {
        stopService();
        startService(isAndroid);
        BluetoothUtil.this.isAndroid = isAndroid;
    }

    @SuppressLint("HandlerLeak")
    private final Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case BluetoothState.MESSAGE_WRITE:
                    break;
                case BluetoothState.MESSAGE_READ:
                    String str = null;
                    int arg1 = msg.arg1;
                    if(arg1==0){
                        str="text";
                    }else if(arg1==1){
                        str="photo";
                    }else if(arg1==2){
                        str="video";
                    }
                    byte[] readBuf = (byte[]) msg.obj;
                    String readMessage = new String(readBuf);
                    if(readBuf != null && readBuf.length > 0) {
                        if(mDataReceivedListener != null)
                            mDataReceivedListener.onDataReceived(readBuf, str);
                    }
                    break;
                case BluetoothState.MESSAGE_DEVICE_NAME:
                    mDeviceName = msg.getData().getString(BluetoothState.DEVICE_NAME);
                    mDeviceAddress = msg.getData().getString(BluetoothState.DEVICE_ADDRESS);
                    if(mBluetoothConnectionListener != null)
                        mBluetoothConnectionListener.onDeviceConnected(mDeviceName, mDeviceAddress);
                    isConnected = true;
                    break;
                case BluetoothState.MESSAGE_TOAST:
                    Toast.makeText(mContext, msg.getData().getString(BluetoothState.TOAST)
                            , Toast.LENGTH_SHORT).show();
                    break;
                case BluetoothState.MESSAGE_STATE_CHANGE:
                    if(mBluetoothStateListener != null)
                        mBluetoothStateListener.onServiceStateChanged(msg.arg1);
                    if(isConnected && msg.arg1 != BluetoothState.STATE_CONNECTED) {

                        if(mBluetoothConnectionListener != null)
                            mBluetoothConnectionListener.onDeviceDisconnected();
                        if(isAutoConnectionEnabled) {
                            isAutoConnectionEnabled = false;
                            autoConnect(keyword);
                        }
                        isConnected = false;
                        mDeviceName = null;
                        mDeviceAddress = null;
                    }

                    if(!isConnecting && msg.arg1 == BluetoothState.STATE_CONNECTING) {
                        isConnecting = true;
                    } else if(isConnecting) {
                        if(msg.arg1 != BluetoothState.STATE_CONNECTED) {
                            if(mBluetoothConnectionListener != null)
                                mBluetoothConnectionListener.onDeviceConnectionFailed();
                        }
                        isConnecting = false;
                    }
                    break;
            }
        }
    };

    public static int ByteArrayToInt(byte b[]) throws Exception {
        ByteArrayInputStream buf = new ByteArrayInputStream(b);

        DataInputStream dis= new DataInputStream(buf);
        return dis.readInt();

    }

    public static byte[] intToByteArray(int i) throws Exception {
        ByteArrayOutputStream buf = new ByteArrayOutputStream();
        DataOutputStream dos= new DataOutputStream(buf);
        dos.writeInt(i);
        byte[] b = buf.toByteArray();
        dos.close();
        buf.close();
        return b;
    }

    public void stopAutoConnect() {
        isAutoConnectionEnabled = false;
    }


    public BluetoothDevice connect(Intent data) {
        String address = data.getExtras().getString(BluetoothState.EXTRA_DEVICE_ADDRESS);
        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        mChatService.connect(device);
        return device;
    }

    public void connect(String address) {
        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        mChatService.connect(device);
    }

    public void disconnect() {
        if(mChatService != null) {
            isServiceRunning = false;
            mChatService.stop();
            if(mChatService.getState() == BluetoothState.STATE_NONE) {
                isServiceRunning = true;
                mChatService.start(BluetoothUtil.this.isAndroid);
            }
        }
    }

    public void setBluetoothStateListener (BluetoothStateListener listener) {
        mBluetoothStateListener = listener;
    }

    public void setOnDataReceivedListener (OnDataReceivedListener listener) {
        mDataReceivedListener = listener;
    }

    public void setBluetoothConnectionListener (BluetoothConnectionListener listener) {
        mBluetoothConnectionListener = listener;
    }

    public void setAutoConnectionListener(AutoConnectionListener listener) {
        mAutoConnectionListener = listener;
    }

    public void enable() {
        mBluetoothAdapter.enable();
    }

    public void send(byte[] data, boolean CRLF) {
        if(mChatService.getState() == BluetoothState.STATE_CONNECTED) {
            if(CRLF) {
                byte[] data2 = new byte[data.length + 2];
                for(int i = 0 ; i < data.length ; i++)
                    data2[i] = data[i];
                data2[data2.length - 2] = 0x0A;
                data2[data2.length - 1] = 0x0D;
                mChatService.write(data2);
            } else {
                mChatService.write(data);
            }
        }
    }

    public void send(String data, boolean CRLF) {
        if(mChatService.getState() == BluetoothState.STATE_CONNECTED) {
            if(CRLF)
                data += "\r\n";
            mChatService.write(data.getBytes());
        }
    }

    public void send(byte[] data){
        int length = data.length;
        byte[] length_b = null;
        try {
            length_b= intToByteArray(length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if(length_b == null)return;

        byte[] headerInfo = new byte[headInfoLength];
        for (int i = 0; i < headInfoLength - 4; i++) {
            headerInfo[i] = (byte) i;
        }
        for (int i = 0; i < 4; i++) {
            headerInfo[6+i] = length_b[i];
        }
        byte[] sendMsg = new byte[length + headInfoLength];
        for (int i = 0; i < sendMsg.length; i++) {
            if(i < headInfoLength){
                sendMsg[i] = headerInfo[i];
            }else{
                sendMsg[i] = data[i - headInfoLength];
            }

        }
        mChatService.write(sendMsg);
    }

    public String getConnectedDeviceName() {
        return mDeviceName;
    }

    public String getConnectedDeviceAddress() {
        return mDeviceAddress;
    }

    public String[] getPairedDeviceName() {
        int c = 0;
        Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();
        String[] name_list = new String[devices.size()];
        for(BluetoothDevice device : devices) {
            name_list[c] = device.getName();
            c++;
        }
        return name_list;
    }

    public String[] getPairedDeviceAddress() {
        int c = 0;
        Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();
        String[] address_list = new String[devices.size()];
        for(BluetoothDevice device : devices) {
            address_list[c] = device.getAddress();
            c++;
        }
        return address_list;
    }


    public void autoConnect(String keywordName) {
        if(!isAutoConnectionEnabled) {
            keyword = keywordName;
            isAutoConnectionEnabled = true;
            isAutoConnecting = true;
            if(mAutoConnectionListener != null)
                mAutoConnectionListener.onAutoConnectionStarted();
            final ArrayList<String> arr_filter_address = new ArrayList<String>();
            final ArrayList<String> arr_filter_name = new ArrayList<String>();
            String[] arr_name = getPairedDeviceName();
            String[] arr_address = getPairedDeviceAddress();
            for(int i = 0 ; i < arr_name.length ; i++) {
                if(arr_name[i].contains(keywordName)) {
                    arr_filter_address.add(arr_address[i]);
                    arr_filter_name.add(arr_name[i]);
                }
            }

            bcl = new BluetoothConnectionListener() {
                public void onDeviceConnected(String name, String address) {
                    bcl = null;
                    isAutoConnecting = false;
                }

                public void onDeviceDisconnected() { }
                public void onDeviceConnectionFailed() {
                    Log.e("CHeck", "Failed");
                    if(isServiceRunning) {
                        if(isAutoConnectionEnabled) {
                            c++;
                            if(c >= arr_filter_address.size())
                                c = 0;
                            connect(arr_filter_address.get(c));
                            Log.e("CHeck", "Connect");
                            if(mAutoConnectionListener != null)
                                mAutoConnectionListener.onNewConnection(arr_filter_name.get(c)
                                        , arr_filter_address.get(c));
                        } else {
                            bcl = null;
                            isAutoConnecting = false;
                        }
                    }
                }
            };

            setBluetoothConnectionListener(bcl);
            c = 0;
            if(mAutoConnectionListener != null)
                mAutoConnectionListener.onNewConnection(arr_name[c], arr_address[c]);
            if(arr_filter_address.size() > 0)
                connect(arr_filter_address.get(c));
            else
                Toast.makeText(mContext, "Device name mismatch", Toast.LENGTH_SHORT).show();
        }
    }

BluetoothState蓝牙状态码
    public class BluetoothState {
    public static final int STATE_NONE = 0;
    public static final int STATE_LISTEN = 1;
    public static final int STATE_CONNECTING = 2;
    public static final int STATE_CONNECTED = 3;
    public static final int STATE_NULL = -1;

    public static final int MESSAGE_STATE_CHANGE = 1;
    public static final int MESSAGE_READ = 2;
    public static final int MESSAGE_WRITE = 3;
    public static final int MESSAGE_DEVICE_NAME = 4;
    public static final int MESSAGE_TOAST = 5;

    public static final int REQUEST_CONNECT_DEVICE = 384;
    public static final int REQUEST_ENABLE_BT = 385;

    public static final String DEVICE_NAME = "device_name";
    public static final String DEVICE_ADDRESS = "device_address";
    public static final String TOAST = "toast";
    
    public static final boolean DEVICE_ANDROID = true;
    public static final boolean DEVICE_OTHER = false;

    public static String EXTRA_DEVICE_ADDRESS = "device_address";
    
    }

BluetoothService蓝牙状态监听和配对连接
    public class BluetoothService {
    private static final String TAG = "Bluetooth Service";
    private static final String NAME_SECURE = "Bluetooth Secure";
    private static final UUID UUID_ANDROID_DEVICE =
            UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
    private static final UUID UUID_OTHER_DEVICE =
            UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private AcceptThread mSecureAcceptThread;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    private boolean isAndroid = BluetoothState.DEVICE_ANDROID;
    public BluetoothService(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = BluetoothState.STATE_NONE;
        mHandler = handler;
    }
    private synchronized void setState(int state) {
        Log.d(TAG, "setState() " + mState + " -> " + state);
        mState = state;
        mHandler.obtainMessage(BluetoothState.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }
    public synchronized int getState() {
        return mState;
    }
    public synchronized void start(boolean isAndroid) {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }
        setState(BluetoothState.STATE_LISTEN);
        if (mSecureAcceptThread == null) {
            mSecureAcceptThread = new AcceptThread(isAndroid);
            mSecureAcceptThread.start();
            BluetoothService.this.isAndroid = isAndroid;
        }
    }

    public synchronized void connect(BluetoothDevice device) {
        if (mState == BluetoothState.STATE_CONNECTING) {
            if (mConnectThread != null) {
                mConnectThread.cancel();
                mConnectThread = null;
            }
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        mConnectThread = new ConnectThread(device);
        mConnectThread.start();
        setState(BluetoothState.STATE_CONNECTING);
    }

    public synchronized void connected(BluetoothSocket socket, BluetoothDevice
            device, final String socketType) {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        if (mSecureAcceptThread != null) {
            mSecureAcceptThread.cancel();
            mSecureAcceptThread = null;
        }

        mConnectedThread = new ConnectedThread(socket, socketType);
        mConnectedThread.start();

        Message msg = mHandler.obtainMessage(BluetoothState.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothState.DEVICE_NAME, device.getName());
        bundle.putString(BluetoothState.DEVICE_ADDRESS, device.getAddress());
        msg.setData(bundle);
        mHandler.sendMessage(msg);

        setState(BluetoothState.STATE_CONNECTED);
    }

    public synchronized void stop() {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        if (mSecureAcceptThread != null) {
            mSecureAcceptThread.cancel();
            mSecureAcceptThread.kill();
            mSecureAcceptThread = null;
        }
        setState(BluetoothState.STATE_NONE);
    }

    public void write(byte[] out) {
        ConnectedThread r;
        synchronized (this) {
            if (mState != BluetoothState.STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        r.write(out);
    }

    private void connectionFailed() {
        BluetoothService.this.start(BluetoothService.this.isAndroid);
    }

    private void connectionLost() {
        BluetoothService.this.start(BluetoothService.this.isAndroid);
    }

    private class AcceptThread extends Thread {
        private BluetoothServerSocket mmServerSocket;
        private String mSocketType;
        boolean isRunning = true;

        public AcceptThread(boolean isAndroid) {
            BluetoothServerSocket tmp = null;
            try {
                if (isAndroid)
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_ANDROID_DEVICE);
                else
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_OTHER_DEVICE);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }

        public void run() {
            setName("AcceptThread" + mSocketType);
            BluetoothSocket socket = null;

            while (mState != BluetoothState.STATE_CONNECTED && isRunning) {
                try {
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }

                if (socket != null) {
                    synchronized (BluetoothService.this) {
                        switch (mState) {
                            case BluetoothState.STATE_LISTEN:
                            case BluetoothState.STATE_CONNECTING:
                                connected(socket, socket.getRemoteDevice(),
                                        mSocketType);
                                break;
                            case BluetoothState.STATE_NONE:
                            case BluetoothState.STATE_CONNECTED:
                                try {
                                    socket.close();
                                } catch (IOException e) {
                                }
                                break;
                        }
                    }
                }
            }
        }

        public void cancel() {
            try {
                mmServerSocket.close();
                mmServerSocket = null;
            } catch (IOException e) {

            }
        }

        public void kill() {
            isRunning = false;
        }
    }


    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
        private String mSocketType;

        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;

            try {
                if (BluetoothService.this.isAndroid)
                    tmp = device.createRfcommSocketToServiceRecord(UUID_ANDROID_DEVICE);
                else
                    tmp = device.createRfcommSocketToServiceRecord(UUID_OTHER_DEVICE);
            } catch (IOException e) {
            }
            mmSocket = tmp;
        }

        public void run() {
            mAdapter.cancelDiscovery();
            try {
                mmSocket.connect();
            } catch (IOException e) {
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                }
                connectionFailed();
                return;
            }
            synchronized (BluetoothService.this) {
                mConnectThread = null;
            }

            connected(mmSocket, mmDevice, mSocketType);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
            }
        }
    }

    public static int ByteArrayToInt(byte b[]) throws Exception {
        ByteArrayInputStream buf = new ByteArrayInputStream(b);

        DataInputStream dis = new DataInputStream(buf);
        return dis.readInt();

    }


    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket, String socketType) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
            byte[] buffer;
            ArrayList<Integer> arr_byte = new ArrayList<Integer>();

            while (true) {
                try {
                    boolean valid = true;
                    for (int i = 0; i < 6; i++) {
                        int t = mmInStream.read();
                        if (t != i) {
                            valid = false;
                            break;
                        }
                    }

                    if (valid) {
                        byte[] bufLength = new byte[4];
                        for (int i = 0; i < 4; i++) {
                            bufLength[i] = ((Integer) mmInStream.read()).byteValue();
                        }
                        int length = ByteArrayToInt(bufLength);
                        buffer = new byte[length];
                        for (int i = 0; i < length; i++) {
                            buffer[i] = ((Integer) mmInStream.read()).byteValue();
                        }
                        mHandler.obtainMessage(BluetoothState.MESSAGE_READ,
                                buffer).sendToTarget();

                    }

                } catch (IOException e) {
                    connectionLost();
                    BluetoothService.this.start(BluetoothService.this.isAndroid);
                    break;
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

        public void write(byte[] buffer) {
            try {
                mmOutStream.write(buffer);
            } catch (IOException e) {
            }
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
            }
        }
    }
    }
以上是发射端部分ReceiveClient，下面是蓝牙接受端部分：
发射端layout：

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.rejointech.receiveclient.MainActivity">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:id="@+id/photo"/>

    <ImageView
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:id="@+id/video"/>
    <Button
        android:text="蓝牙"
        android:textColor="#000"
        android:textSize="20sp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="Click"/>
    </LinearLayout>
发射端主界面
    public class MainActivity extends AppCompatActivity {
    private BluetoothUtil mBt;
    private ImageView mPhoto;
    private ImageView mVideo;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mBt = new BluetoothUtil(this);
        initBlue();
        initView();
    }

    private void initView() {
        mPhoto = (ImageView) findViewById(R.id.photo);
        mVideo = (ImageView) findViewById(R.id.video);
    }

    private void initBlue() {
        if (!mBt.isBluetoothAvailable()) {
            Toast.makeText(getApplicationContext(), "Bluetooth is not available", Toast.LENGTH_SHORT).show();
            finish();
        }

        mBt.setOnDataReceivedListener(new BluetoothUtil.OnDataReceivedListener() {
            public void onDataReceived(byte[] data, String message) {
                if (message.equals("text") && data.length != 0) {
                    String text = new String(data);
                    Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show();
                } else if (message.equals("photo") && data.length != 0) {
                    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
                    mPhoto.setImageBitmap(bitmap);
                } else if (message.equals("video") && data.length != 0) {
                    mVideo.setImageBitmap(BitmapFactory.decodeByteArray(data, 0, data.length));
                }
            }
        });

        mBt.setBluetoothConnectionListener(new BluetoothUtil.BluetoothConnectionListener() {
            public void onDeviceConnected(String name, String address) {
                Toast.makeText(MainActivity.this,"蓝牙已连接",Toast.LENGTH_SHORT).show();
            }

            public void onDeviceDisconnected() {
                Toast.makeText(MainActivity.this,"蓝牙已断开",Toast.LENGTH_SHORT).show();
            }

            public void onDeviceConnectionFailed() {

            }
        });

    }

    public void Click(View view) {
        if (mBt.getServiceState() == BluetoothState.STATE_CONNECTED) {
            mBt.disconnect();
        } else {
            Intent intent = new Intent(getApplicationContext(), BluetoothActivity.class);
            startActivityForResult(intent, BluetoothState.REQUEST_CONNECT_DEVICE);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == BluetoothState.REQUEST_CONNECT_DEVICE) {
            if (resultCode == Activity.RESULT_OK)
                mBt.connect(data);
        } else if (requestCode == BluetoothState.REQUEST_ENABLE_BT) {
            if (resultCode == Activity.RESULT_OK) {
                mBt.setupService();
                mBt.startService(BluetoothState.DEVICE_ANDROID);
            } else {
                finish();
            }
        }
    }

    public void onStart() {
        super.onStart();
        if (!mBt.isBluetoothEnabled()) {
            //打开蓝牙
            Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(intent, BluetoothState.REQUEST_ENABLE_BT);
        } else {
            if (!mBt.isServiceAvailable()) {
                //开启监听
                mBt.setupService();
                mBt.startService(BluetoothState.DEVICE_ANDROID);
            }
        }
    }
    }

#蓝牙列表界面好状态码的类和发射端的一样，就不帖了，下面是接收端的BluetoothUtil
    public class BluetoothUtil {
    private BluetoothStateListener mBluetoothStateListener = null;
    private OnDataReceivedListener mDataReceivedListener = null;
    private BluetoothConnectionListener mBluetoothConnectionListener = null;
    private AutoConnectionListener mAutoConnectionListener = null;
    private Context mContext;
    private BluetoothAdapter mBluetoothAdapter = null;
    private BluetoothService mChatService = null;
    private String mDeviceName = null;
    private String mDeviceAddress = null;
    private boolean isAutoConnecting = false;
    private boolean isAutoConnectionEnabled = false;
    private boolean isConnected = false;
    private boolean isConnecting = false;
    private boolean isServiceRunning = false;
    private String keyword = "";
    private boolean isAndroid = BluetoothState.DEVICE_ANDROID;
    private BluetoothConnectionListener bcl;
    private int c = 0;
    private static int headInfoLength = 10;

    //获取蓝牙adapter
    public BluetoothUtil(Context context) {
        mContext = context;
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    }

    //判断蓝牙是否可用
    public boolean isBluetoothEnable() {
        return mBluetoothAdapter.isEnabled();
    }

    public interface BluetoothStateListener {
        public void onServiceStateChanged(int state);
    }

    public interface OnDataReceivedListener {
        public void onDataReceived(byte[] data, String message);
    }

    public interface BluetoothConnectionListener {
        public void onDeviceConnected(String name, String address);
        public void onDeviceDisconnected();
        public void onDeviceConnectionFailed();
    }

    public interface AutoConnectionListener {
        public void onAutoConnectionStarted();
        public void onNewConnection(String name, String address);
    }

    public boolean isBluetoothAvailable() {
        try {
            if (mBluetoothAdapter == null || mBluetoothAdapter.getAddress().equals(null))
                return false;
        } catch (NullPointerException e) {
            return false;
        }
        return true;
    }

    public boolean isBluetoothEnabled() {
        return mBluetoothAdapter.isEnabled();
    }

    public boolean isServiceAvailable() {
        return mChatService != null;
    }

    public boolean isAutoConnecting() {
        return isAutoConnecting;
    }

    public boolean startDiscovery() {
        return mBluetoothAdapter.startDiscovery();
    }

    public boolean isDiscovery() {
        return mBluetoothAdapter.isDiscovering();
    }

    public boolean cancelDiscovery() {
        return mBluetoothAdapter.cancelDiscovery();
    }

    public void setupService() {
        mChatService = new BluetoothService(mContext, mHandler);
    }

    public BluetoothAdapter getBluetoothAdapter() {
        return mBluetoothAdapter;
    }

    public int getServiceState() {
        if(mChatService != null)
            return mChatService.getState();
        else
            return -1;
    }

    //开启蓝牙一直监听是否连接的状态
    public void startService(boolean isAndroid) {
        if (mChatService != null) {
            if (mChatService.getState() == BluetoothState.STATE_NONE) {
                isServiceRunning = true;
                mChatService.start(isAndroid);
                BluetoothUtil.this.isAndroid = isAndroid;
            }
        }
    }

    public void stopService() {
        if (mChatService != null) {
            isServiceRunning = false;
            mChatService.stop();
        }
        new Handler().postDelayed(new Runnable() {
            public void run() {
                if (mChatService != null) {
                    isServiceRunning = false;
                    mChatService.stop();
                }
            }
        }, 500);
    }

    public void setDeviceTarget(boolean isAndroid) {
        stopService();
        startService(isAndroid);
        BluetoothUtil.this.isAndroid = isAndroid;
    }

    @SuppressLint("HandlerLeak")
    private final Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case BluetoothState.MESSAGE_WRITE:
                    break;
                case BluetoothState.MESSAGE_READ:
                    String str = null;
                    int arg1 = msg.arg1;
                    if(arg1==0){
                        str="text";
                    }else if(arg1==1){
                        str="photo";
                    }else if(arg1==2){
                        str="video";
                    }
                    byte[] readBuf = (byte[]) msg.obj;
//                String readMessage = new String(readBuf);
                    if(readBuf != null && readBuf.length > 0) {
                        if(mDataReceivedListener != null)
                            mDataReceivedListener.onDataReceived(readBuf, str);
                    }
                    break;
                case BluetoothState.MESSAGE_DEVICE_NAME:
                    mDeviceName = msg.getData().getString(BluetoothState.DEVICE_NAME);
                    mDeviceAddress = msg.getData().getString(BluetoothState.DEVICE_ADDRESS);
                    if(mBluetoothConnectionListener != null)
                        mBluetoothConnectionListener.onDeviceConnected(mDeviceName, mDeviceAddress);
                    isConnected = true;
                    break;
                case BluetoothState.MESSAGE_TOAST:
                    Toast.makeText(mContext, msg.getData().getString(BluetoothState.TOAST)
                            , Toast.LENGTH_SHORT).show();
                    break;
                case BluetoothState.MESSAGE_STATE_CHANGE:
                    if(mBluetoothStateListener != null)
                        mBluetoothStateListener.onServiceStateChanged(msg.arg1);
                    if(isConnected && msg.arg1 != BluetoothState.STATE_CONNECTED) {

                        if(mBluetoothConnectionListener != null)
                            mBluetoothConnectionListener.onDeviceDisconnected();
                        if(isAutoConnectionEnabled) {
                            isAutoConnectionEnabled = false;
                            autoConnect(keyword);
                        }
                        isConnected = false;
                        mDeviceName = null;
                        mDeviceAddress = null;
                    }

                    if(!isConnecting && msg.arg1 == BluetoothState.STATE_CONNECTING) {
                        isConnecting = true;
                    } else if(isConnecting) {
                        if(msg.arg1 != BluetoothState.STATE_CONNECTED) {
                            if(mBluetoothConnectionListener != null)
                                mBluetoothConnectionListener.onDeviceConnectionFailed();
                        }
                        isConnecting = false;
                    }
                    break;
            }
        }
    };

    public static int ByteArrayToInt(byte b[]) throws Exception {
        ByteArrayInputStream buf = new ByteArrayInputStream(b);

        DataInputStream dis= new DataInputStream(buf);
        return dis.readInt();

    }

    public static byte[] intToByteArray(int i) throws Exception {
        ByteArrayOutputStream buf = new ByteArrayOutputStream();
        DataOutputStream dos= new DataOutputStream(buf);
        dos.writeInt(i);
        byte[] b = buf.toByteArray();
        dos.close();
        buf.close();
        return b;
    }

    public void stopAutoConnect() {
        isAutoConnectionEnabled = false;
    }


    public BluetoothDevice connect(Intent data) {
        String address = data.getExtras().getString(BluetoothState.EXTRA_DEVICE_ADDRESS);
        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        mChatService.connect(device);
        return device;
    }

    public void connect(String address) {
        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        mChatService.connect(device);
    }

    public void disconnect() {
        if(mChatService != null) {
            isServiceRunning = false;
            mChatService.stop();
            if(mChatService.getState() == BluetoothState.STATE_NONE) {
                isServiceRunning = true;
                mChatService.start(BluetoothUtil.this.isAndroid);
            }
        }
    }

    public void setBluetoothStateListener (BluetoothStateListener listener) {
        mBluetoothStateListener = listener;
    }

    public void setOnDataReceivedListener (OnDataReceivedListener listener) {
        mDataReceivedListener = listener;
    }

    public void setBluetoothConnectionListener (BluetoothConnectionListener listener) {
        mBluetoothConnectionListener = listener;
    }

    public void setAutoConnectionListener(AutoConnectionListener listener) {
        mAutoConnectionListener = listener;
    }

    public void enable() {
        mBluetoothAdapter.enable();
    }

    public void send(byte[] data, boolean CRLF) {
        if(mChatService.getState() == BluetoothState.STATE_CONNECTED) {
            if(CRLF) {
                byte[] data2 = new byte[data.length + 2];
                for(int i = 0 ; i < data.length ; i++)
                    data2[i] = data[i];
                data2[data2.length - 2] = 0x0A;
                data2[data2.length - 1] = 0x0D;
                mChatService.write(data2);
            } else {
                mChatService.write(data);
            }
        }
    }

    public void send(String data, boolean CRLF) {
        if(mChatService.getState() == BluetoothState.STATE_CONNECTED) {
            if(CRLF)
                data += "\r\n";
            mChatService.write(data.getBytes());
        }
    }

    public void send(byte[] data){
        int length = data.length;
        byte[] length_b = null;
        try {
            length_b= intToByteArray(length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        if(length_b == null)return;

        byte[] headerInfo = new byte[headInfoLength];
        for (int i = 0; i < headInfoLength - 4; i++) {
            headerInfo[i] = (byte) i;
        }
        for (int i = 0; i < 4; i++) {
            headerInfo[6+i] = length_b[i];
        }
        byte[] sendMsg = new byte[length + headInfoLength];
        for (int i = 0; i < sendMsg.length; i++) {
            if(i < headInfoLength){
                sendMsg[i] = headerInfo[i];
            }else{
                sendMsg[i] = data[i - headInfoLength];
            }

        }
        mChatService.write(sendMsg);
    }

    public String getConnectedDeviceName() {
        return mDeviceName;
    }

    public String getConnectedDeviceAddress() {
        return mDeviceAddress;
    }

    public String[] getPairedDeviceName() {
        int c = 0;
        Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();
        String[] name_list = new String[devices.size()];
        for(BluetoothDevice device : devices) {
            name_list[c] = device.getName();
            c++;
        }
        return name_list;
    }

    public String[] getPairedDeviceAddress() {
        int c = 0;
        Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();
        String[] address_list = new String[devices.size()];
        for(BluetoothDevice device : devices) {
            address_list[c] = device.getAddress();
            c++;
        }
        return address_list;
    }


    public void autoConnect(String keywordName) {
        if(!isAutoConnectionEnabled) {
            keyword = keywordName;
            isAutoConnectionEnabled = true;
            isAutoConnecting = true;
            if(mAutoConnectionListener != null)
                mAutoConnectionListener.onAutoConnectionStarted();
            final ArrayList<String> arr_filter_address = new ArrayList<String>();
            final ArrayList<String> arr_filter_name = new ArrayList<String>();
            String[] arr_name = getPairedDeviceName();
            String[] arr_address = getPairedDeviceAddress();
            for(int i = 0 ; i < arr_name.length ; i++) {
                if(arr_name[i].contains(keywordName)) {
                    arr_filter_address.add(arr_address[i]);
                    arr_filter_name.add(arr_name[i]);
                }
            }

            bcl = new BluetoothConnectionListener() {
                public void onDeviceConnected(String name, String address) {
                    bcl = null;
                    isAutoConnecting = false;
                }

                public void onDeviceDisconnected() { }
                public void onDeviceConnectionFailed() {
                    Log.e("CHeck", "Failed");
                    if(isServiceRunning) {
                        if(isAutoConnectionEnabled) {
                            c++;
                            if(c >= arr_filter_address.size())
                                c = 0;
                            connect(arr_filter_address.get(c));
                            Log.e("CHeck", "Connect");
                            if(mAutoConnectionListener != null)
                                mAutoConnectionListener.onNewConnection(arr_filter_name.get(c)
                                        , arr_filter_address.get(c));
                        } else {
                            bcl = null;
                            isAutoConnecting = false;
                        }
                    }
                }
            };

            setBluetoothConnectionListener(bcl);
            c = 0;
            if(mAutoConnectionListener != null)
                mAutoConnectionListener.onNewConnection(arr_name[c], arr_address[c]);
            if(arr_filter_address.size() > 0)
                connect(arr_filter_address.get(c));
            else
                Toast.makeText(mContext, "Device name mismatch", Toast.LENGTH_SHORT).show();
        }
    }
    }
接收端的BluetoothService,核心部分是ConnectedThread这个线程
    public class BluetoothService {
    private static final String TAG = "Bluetooth Service";
    private static final String NAME_SECURE = "Bluetooth Secure";
    private static final UUID UUID_ANDROID_DEVICE =
            UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
    private static final UUID UUID_OTHER_DEVICE =
            UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

    private final BluetoothAdapter mAdapter;
    private final Handler mHandler;
    private AcceptThread mSecureAcceptThread;
    private ConnectThread mConnectThread;
    private ConnectedThread mConnectedThread;
    private int mState;
    private boolean isAndroid = BluetoothState.DEVICE_ANDROID;

    public BluetoothService(Context context, Handler handler) {
        mAdapter = BluetoothAdapter.getDefaultAdapter();
        mState = BluetoothState.STATE_NONE;
        mHandler = handler;
    }


    private synchronized void setState(int state) {
        Log.d(TAG, "setState() " + mState + " -> " + state);
        mState = state;

        mHandler.obtainMessage(BluetoothState.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
    }

    public synchronized int getState() {
        return mState;
    }

    //开启子线程
    public synchronized void start(boolean isAndroid) {
        // Cancel any thread attempting to make a connection
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        setState(BluetoothState.STATE_LISTEN);

        //开启子线程
        if (mSecureAcceptThread == null) {
            mSecureAcceptThread = new AcceptThread(isAndroid);
            mSecureAcceptThread.start();
            BluetoothService.this.isAndroid = isAndroid;
        }
    }

    public synchronized void connect(BluetoothDevice device) {
        // Cancel any thread attempting to make a connection
        if (mState == BluetoothState.STATE_CONNECTING) {
            if (mConnectThread != null) {
                mConnectThread.cancel();
                mConnectThread = null;
            }
        }

        // Cancel any thread currently running a connection
        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        // Start the thread to connect with the given device
        mConnectThread = new ConnectThread(device);
        mConnectThread.start();
        setState(BluetoothState.STATE_CONNECTING);
    }

    /**
     * Start the ConnectedThread to begin managing a Bluetooth connection
     *
     * @param socket The BluetoothSocket on which the connection was made
     * @param device The BluetoothDevice that has been connected
     */
    public synchronized void connected(BluetoothSocket socket, BluetoothDevice
            device, final String socketType) {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        if (mSecureAcceptThread != null) {
            mSecureAcceptThread.cancel();
            mSecureAcceptThread = null;
        }

        mConnectedThread = new ConnectedThread(socket, socketType);
        mConnectedThread.start();

        Message msg = mHandler.obtainMessage(BluetoothState.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();
        bundle.putString(BluetoothState.DEVICE_NAME, device.getName());
        bundle.putString(BluetoothState.DEVICE_ADDRESS, device.getAddress());
        msg.setData(bundle);
        mHandler.sendMessage(msg);
        setState(BluetoothState.STATE_CONNECTED);
    }

    public synchronized void stop() {
        if (mConnectThread != null) {
            mConnectThread.cancel();
            mConnectThread = null;
        }

        if (mConnectedThread != null) {
            mConnectedThread.cancel();
            mConnectedThread = null;
        }

        if (mSecureAcceptThread != null) {
            mSecureAcceptThread.cancel();
            mSecureAcceptThread.kill();
            mSecureAcceptThread = null;
        }
        setState(BluetoothState.STATE_NONE);
    }

    public void write(byte[] out) {
        ConnectedThread r;
        synchronized (this) {
            if (mState != BluetoothState.STATE_CONNECTED) return;
            r = mConnectedThread;
        }
        r.write(out);
    }

    private void connectionFailed() {
        BluetoothService.this.start(BluetoothService.this.isAndroid);
    }

    private void connectionLost() {
        BluetoothService.this.start(BluetoothService.this.isAndroid);
    }

    //监听蓝牙连接的线程
    private class AcceptThread extends Thread {
        private BluetoothServerSocket mmServerSocket;
        private String mSocketType;
        boolean isRunning = true;

        public AcceptThread(boolean isAndroid) {
            BluetoothServerSocket tmp = null;
            try {
                if (isAndroid)
                    //获取蓝牙socket
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_ANDROID_DEVICE);
                else
                    tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE, UUID_OTHER_DEVICE);
            } catch (IOException e) {
            }
            mmServerSocket = tmp;
        }

        public void run() {
            setName("AcceptThread" + mSocketType);
            BluetoothSocket socket = null;
            //死循环监听蓝牙连接状态，首次今进入一定满足条件，蓝牙连上后，循环停止
            while (mState != BluetoothState.STATE_CONNECTED && isRunning) {
                try {
                    socket = mmServerSocket.accept();
                } catch (IOException e) {
                    break;
                }

                if (socket != null) {
                    synchronized (BluetoothService.this) {
                        switch (mState) {
                            case BluetoothState.STATE_LISTEN:
                            case BluetoothState.STATE_CONNECTING:
                                connected(socket, socket.getRemoteDevice(),
                                        mSocketType);
                                break;
                            case BluetoothState.STATE_NONE:
                            case BluetoothState.STATE_CONNECTED:
                                try {
                                    socket.close();
                                } catch (IOException e) {
                                }
                                break;
                        }
                    }
                }
            }
        }

        public void cancel() {
            try {
                mmServerSocket.close();
                mmServerSocket = null;
            } catch (IOException e) {
            }
        }

        public void kill() {
            isRunning = false;
        }
    }


    private class ConnectThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;
        private String mSocketType;

        public ConnectThread(BluetoothDevice device) {
            mmDevice = device;
            BluetoothSocket tmp = null;

            try {
                if (BluetoothService.this.isAndroid)
                    tmp = device.createRfcommSocketToServiceRecord(UUID_ANDROID_DEVICE);
                else
                    tmp = device.createRfcommSocketToServiceRecord(UUID_OTHER_DEVICE);
            } catch (IOException e) {
            }
            mmSocket = tmp;
        }

        public void run() {
            mAdapter.cancelDiscovery();

            try {
                mmSocket.connect();
            } catch (IOException e) {
                try {
                    mmSocket.close();
                } catch (IOException e2) {
                }
                connectionFailed();
                return;
            }

            synchronized (BluetoothService.this) {
                mConnectThread = null;
            }
            connected(mmSocket, mmDevice, mSocketType);
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {
            }
        }
    }

    public static int ByteArrayToInt(byte b[]) throws Exception {
        ByteArrayInputStream buf = new ByteArrayInputStream(b);
        DataInputStream dis = new DataInputStream(buf);
        return dis.readInt();

    }

    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;``
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket, String socketType) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
            byte[] buffer;
            ArrayList<Integer> arr_byte = new ArrayList<Integer>();
            while (true) {
                try {
                    boolean valid = true;
                    //判断前六位是不是12345
                    for (int i = 0; i < 6; i++) {
                        int t = mmInStream.read();
                        if (t != i) {
                            valid = false;
                            break;
                        }
                    }
                    if (valid) {
                        byte[] bufLength = new byte[4];
                        for (int i = 0; i < 4; i++) {
                            bufLength[i] = ((Integer) mmInStream.read()).byteValue();
                        }

                        int textCount = 0;
                        int photoCount = 0;
                        int videoCount = 0;

                        for (int i = 0; i < 4; i++) {
                            int read = mmInStream.read();
                            if (read == 0) {
                                textCount++;
                            } else if (read == 1) {
                                photoCount++;
                            } else if (read == 2) {
                                videoCount++;
                            }
                        }
                        int length = ByteArrayToInt(bufLength);
                        buffer = new byte[length];
                        for (int i = 0; i < length; i++) {
                            buffer[i] = ((Integer) mmInStream.read()).byteValue();
                        }
                        Message msg = Message.obtain();
                        msg.what = BluetoothState.MESSAGE_READ;
                        msg.obj = buffer;

                        if (textCount == 4) {
                            msg.arg1 = 0;
                            mHandler.sendMessage(msg);
                        } else if (photoCount == 4) {
                            msg.arg1 = 1;
                            mHandler.sendMessage(msg);
                        } else if (videoCount == 4) {
                            msg.arg1 = 2;
                            mHandler.sendMessage(msg);
                        }
                    }

                } catch (IOException e) {
                    connectionLost();
                    BluetoothService.this.start(BluetoothService.this.isAndroid);
                    break;
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

        public void write(byte[] buffer) {
            try {/*
                byte[] buffer2 = new byte[buffer.length + 2];
                for(int i = 0 ; i < buffer.length ; i++) 
                    buffer2[i] = buffer[i];
                buffer2[buffer2.length - 2] = 0x0A;
                buffer2[buffer2.length - 1] = 0x0D;*/
                mmOutStream.write(buffer);

            } catch (IOException e) {

            }
        }

        public void cancel() {
            try {
                mmSocket.close();
            } catch (IOException e) {

            }
        }
    }

  }

权限：

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