android开发之蓝牙配对连接的方法「建议收藏」

全栈程序员站长

发布于 2022-03-11 09:17:43

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发布于 2022-03-11 09:17:43

文章被收录于专栏：全栈程序员必看

大家好，又见面了，我是全栈君。

新年第一篇。

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

BluetoothSocket tmp = null;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
         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。

    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():

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。

    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

/**
     * 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。

发布者：全栈程序员栈长，转载请注明出处：https://javaforall.cn/121375.html原文链接：https://javaforall.cn

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