android - 蓝牙 : Do i need to know the UUID of the Devices?

Question

我想将我的 Nexus 7 设备与我的 Nexus 4 设备连接，稍后我想将我的 Nexus 7 设备与微 Controller 连接。 我是否必须知道我的设备的 UUID 才能使用蓝牙连接它们？

当我配对我的设备时，UUID 是否正在交换？

如果是:为什么在android示例中有定义的UUID？

public class BluetoothService extends Thread {
    private static final String TAG = BluetoothService.class.getSimpleName();
    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
    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;
    private BluetoothAdapter bluetoothAdapter = null;
    private Handler handler = null;
    private ConnectThread connectThread = null;
    private ConnectedThread connectedThread = null;
    private int bluetoothState = STATE_NONE;

    public BluetoothService(Handler handler) {
        this.bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        this.bluetoothState = STATE_NONE;
        this.handler = handler;
    }

    public synchronized void startConnection() {
        Log.d(TAG, "start");

        if (this.connectThread != null) {
            this.connectThread.cancel();
            this.connectThread = null;
        }

        if (this.connectedThread != null) {
            this.connectedThread.cancel();
            this.connectedThread = null;
        }

        this.setBluetoothState(STATE_LISTEN);
    }

    public synchronized void connect(BluetoothDevice device) {
        if (this.bluetoothState == STATE_CONNECTING) {
            if (this.connectThread != null) {
                this.connectThread.cancel();
                this.connectThread = null;
            }
        }

        if (this.connectedThread != null) {
            this.connectedThread.cancel();
            this.connectedThread = null;
        }

        this.connectThread = new ConnectThread(device);
        this.connectThread.start();

        this.setBluetoothState(STATE_CONNECTING);
    }

    public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
        if (this.connectThread != null) {
            this.connectThread.cancel();
            this.connectThread = null;
        }

        if (this.connectedThread != null) {
            this.connectedThread.cancel();
            this.connectedThread = null;
        }

        this.connectedThread = new ConnectedThread(socket);
        this.connectedThread.start();

        Message msg = this.handler.obtainMessage(Globals.MESSAGE_DEVICE_NAME);
        Bundle bundle = new Bundle();

        bundle.putString(Globals.DEVICE_NAME, device.getName());
        msg.setData(bundle);

        this.handler.sendMessage(msg);
        this.setBluetoothState(STATE_CONNECTED);
    }

    public synchronized void stopConnection() {
        if (this.connectThread != null) {
            this.connectThread.cancel();
            this.connectThread = null;
        }

        if (this.connectedThread != null) {
            this.connectedThread.cancel();
            this.connectedThread = null;
        }

        this.setBluetoothState(STATE_NONE);
    }

    public void write(byte[] out) {
        ConnectedThread connectedThread = null;

        synchronized (this) {
            if (this.bluetoothState != STATE_CONNECTED) {
                return;
            }

            connectedThread = this.connectedThread;
        }

        connectedThread.write(out);
    }

    private void connectionFailed() {
        Message msg = this.handler.obtainMessage(Globals.MESSAGE_TOAST);

        Bundle bundle = new Bundle();
        bundle.putString(Globals.TOAST, "Unable to connect device");

        msg.setData(bundle);

        this.handler.sendMessage(msg);

        BluetoothService.this.startConnection();
    }

    private void connectionLost() {
        Message msg = this.handler.obtainMessage(Globals.MESSAGE_TOAST);
        Bundle bundle = new Bundle();

        bundle.putString(Globals.TOAST, "Device connection was lost");
        msg.setData(bundle);

        this.handler.sendMessage(msg);

        BluetoothService.this.startConnection();
    }

    public synchronized int getBluetoothState() {
        return this.bluetoothState;
    }

    private synchronized void setBluetoothState(int bluetoothState) {
        this.bluetoothState = bluetoothState;
    }

    private class ConnectThread extends Thread {
        private BluetoothSocket bluetoothSocket = null;
        private BluetoothDevice bluetoothDevice = null;

        public ConnectThread(BluetoothDevice bluetoothDevice) {
            this.bluetoothDevice = bluetoothDevice;

            BluetoothSocket tempBluetoothSocket = null;

            try {
                tempBluetoothSocket = this.bluetoothDevice.createInsecureRfcommSocketToServiceRecord(MY_UUID);
            } catch (IOException e) {
                Log.e(TAG, "Socket Type: " + "create() failed", e);
            }

            this.bluetoothSocket = tempBluetoothSocket;
        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectThread");

            this.setName("ConnectThread");

            bluetoothAdapter.cancelDiscovery();

            try {
                this.bluetoothSocket.connect();
            } catch (IOException e) {
                Log.e(TAG, e.getMessage(), e);

                connectionFailed();

                try {
                    this.bluetoothSocket.close();
                } catch (IOException e2) {
                    Log.e(TAG, "unable to close() socket during connection failure", e2);
                }

                return;
            }

            synchronized (BluetoothService.this) {
                connectThread = null;
            }

            connected(this.bluetoothSocket, this.bluetoothDevice);
        }

        public void cancel() {
            try {
                this.bluetoothSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }

    private class ConnectedThread extends Thread {
        private BluetoothSocket bluetoothSocket = null;
        private InputStream inputStream = null;
        private OutputStream outputStream = null;

        public ConnectedThread(BluetoothSocket bluetoothSocket) {
            Log.d(TAG, "create ConnectedThread");

            this.bluetoothSocket = bluetoothSocket;

            InputStream tempInputStream = null;
            OutputStream tempOutputStream = null;

            try {
                tempInputStream = this.bluetoothSocket.getInputStream();
                tempOutputStream = this.bluetoothSocket.getOutputStream();
            } catch (IOException e) {
                Log.e(TAG, "temp sockets not created", e);
            }

            this.inputStream = tempInputStream;
            this.outputStream = tempOutputStream;
        }

        public void run() {
            byte[] buffer = new byte[1024];
            int bytes = 0;

            while (true) {
                try {
                    bytes = this.inputStream.read(buffer);

                    handler.obtainMessage(Globals.MESSAGE_READ, bytes, -1, buffer).sendToTarget();
                } catch (IOException e) {
                    Log.e(TAG, "disconnected", e);

                    connectionLost();

                    BluetoothService.this.start();

                    break;
                }
            }
        }

        public void write(byte[] buffer) {
            try {
                this.outputStream.write(buffer);

                handler.obtainMessage(Globals.MESSAGE_WRITE, -1, -1, buffer).sendToTarget();
            } catch (IOException e) {
                Log.e(TAG, "Exception during write", e);
            }
        }

        public void cancel() {
            try {
                this.bluetoothSocket.close();
            } catch (IOException e) {
                Log.e(TAG, "close() of connect socket failed", e);
            }
        }
    }
}

如果不是:如何交换 UUID 以便能够连接设备？

Answer 1

google sample/example 中定义的 UUID 必须为服务器和客户端所知:

• 服务器创建一个 RFcomm ServerSocket 来监听带有此 UUID 的传入连接
• 客户端创建一个 RFcomm 蓝牙套接字，它将尝试连接到服务器套接字

如果 uuid 匹配，则建立连接。

配对会保存有关远程设备的信息(名称、地址等)，这样当你想再次连接时，你不必搜索设备来获取它们 =)