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;
}
}
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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;
}
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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。