最近在做蓝牙开锁的小项目，手机去连接单片机总是出现问题，和手机的连接也不稳定，看了不少蓝牙方面的文档，做了个关于蓝牙连接的小结。
在做android蓝牙串口连接的时候一般会使用
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BluetoothSocket tmp = null;// Get a BluetoothSocket for a connection with the// given BluetoothDevicetry { tmp = device.createRfcommSocketToServiceRecord(MY_UUID);} catch (IOException e) { Log.e(TAG, "create() failed", e);} |
然后是tmp赋给BluetoothSocket,接着调用connect方法进行蓝牙设备的连接。
可是 BluetoothSocket 的connect方法本身就会报很多异常错误。
以下根据对蓝牙开发的一点研究可通过以下方法解决：
方法1.先进行蓝牙自动配对，配对成功，通过UUID获得BluetoothSocket,然后执行connect()方法。
方法2.通过UUID获得BluetoothSocket,然后先根据mDevice.getBondState()进行判断是否需要配对，最后执行connnect()方法。
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private class ConnectThread extends Thread { String macAddress = ""; public ConnectThread(String mac) { macAddress = mac; } public void run() { connecting = true; connected = false; if(mBluetoothAdapter == null){ mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); } mBluetoothDevice = mBluetoothAdapter.getRemoteDevice(macAddress); mBluetoothAdapter.cancelDiscovery(); try { socket = mBluetoothDevice.createRfcommSocketToServiceRecord(uuid); } catch (IOException e) { // TODO Auto-generated catch block //e.printStackTrace(); Log.e(TAG, "Socket", e); } //adapter.cancelDiscovery(); while (!connected && connetTime <= 10) { connectDevice(); } // 重置ConnectThread //synchronized (BluetoothService.this) { //ConnectThread = null; //} } public void cancel() { try { socket.close(); socket = null; } catch (Exception e) { e.printStackTrace(); } finally { connecting = false; } }} |
接下来是调用的连接设备方法connectDevice():
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protected void connectDevice() { try { // 连接建立之前的先配对 if (mBluetoothDevice.getBondState() == BluetoothDevice.BOND_NONE) { Method creMethod = BluetoothDevice.class .getMethod("createBond"); Log.e("TAG", "开始配对"); creMethod.invoke(mBluetoothDevice); } else { } } catch (Exception e) { // TODO: handle exception //DisplayMessage("无法配对！"); e.printStackTrace(); } mBluetoothAdapter.cancelDiscovery(); try { socket.connect(); //DisplayMessage("连接成功!"); //connetTime++; connected = true; } catch (IOException e) { // TODO: handle exception //DisplayMessage("连接失败！"); connetTime++; connected = false; try { socket.close(); socket = null; } catch (IOException e2) { // TODO: handle exception Log.e(TAG, "Cannot close connection when connection failed"); } } finally { connecting = false; } } |
方法3.利用反射通过端口获得BluetoothSocket,然后执行connect()方法。
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private class ConnectThread extends Thread { String macAddress = ""; public ConnectThread(String mac) { macAddress = mac; } public void run() { connecting = true; connected = false; if(mBluetoothAdapter == null){ mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); } mBluetoothDevice = mBluetoothAdapter.getRemoteDevice(macAddress); mBluetoothAdapter.cancelDiscovery(); initSocket(); //adapter.cancelDiscovery(); while (!connected && connetTime <= 10) { try { socket.connect(); connected = true; } catch (IOException e1) { connetTime++; connected = false; // 关闭 socket try { socket.close(); socket = null; } catch (IOException e2) { //TODO: handle exception Log.e(TAG, "Socket", e2); } } finally { connecting = false; } //connectDevice(); } // 重置ConnectThread //synchronized (BluetoothService.this) { //ConnectThread = null; //} } public void cancel() { try { socket.close(); socket = null; } catch (Exception e) { e.printStackTrace(); } finally { connecting = false; } }} |
接下来是初始化并得到BluetoothSocket的方法
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/** * 取得BluetoothSocket */ private void initSocket() { BluetoothSocket temp = null; try { Method m = mBluetoothDevice.getClass().getMethod( "createRfcommSocket", new Class[] { int.class }); temp = (BluetoothSocket) m.invoke(mBluetoothDevice, 1);//这里端口为1 } catch (SecurityException e) { e.printStackTrace(); } catch (NoSuchMethodException e) { e.printStackTrace(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } socket = temp; } |
要点：1.蓝牙配对和连接是两回事，不可混为一谈。
2.蓝牙串口连接可通过端口 （1-30）和UUID两种方法进行操作。
3.通过UUID进行蓝牙连接最好先进行配对操作。