Android 经典蓝牙的配置和使用

第一步

  //获取系统蓝牙适配器管理类
    private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter
            .getDefaultAdapter();
private void initBluetooth() {
        // 询问打开蓝牙
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            // Android M Permission check
            if (this.checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
            }
        }
        if (mBluetoothAdapter != null && !mBluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new Intent(
                    BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, 1);
        } else {
            mBluetoothAdapter.startDiscovery();
        }

        // 注册用以接收到已搜索到的蓝牙设备的receiver
        IntentFilter mFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(mBluetoothReceiver, mFilter);
        // 注册搜索完时的receiver
        mFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        registerReceiver(mBluetoothReceiver, mFilter);

    }

第二步

// 广播接收发现蓝牙设备
    private BroadcastReceiver mBluetoothReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                //发现蓝牙设备
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                //根据你的设备address或者name来判断是否是你指定的设备
                if (device.getAddress() != null && deviceName.contains(device.getAddress())) {
                    tagDevice = device;
                    //开启新线程进行连接
                    new ClientThread(tagDevice).start();
                    mBluetoothAdapter.cancelDiscovery();
                    return;
                }

            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                //蓝牙搜索完成
                // 蓝牙搜索是非常消耗系统资源开销的过程，搜索完毕后应该及时取消搜索
                mBluetoothAdapter.cancelDiscovery();
            }
        }
    };

第三步

 /**
     * 蓝牙连接的线程
     */
    private class ClientThread extends Thread {

        private BluetoothDevice device;

        public ClientThread(BluetoothDevice device) {
            this.device = device;
        }

        @Override
        public void run() {

            try {
                socket = device.createRfcommSocketToServiceRecord(UUID.fromString(BLUETOOTH_UUID));
                Log.d("Bluetooth", "连接服务端...");
                if (socket != null && !socket.isConnected()) {
                    Method m = device.getClass().getMethod("createRfcommSocket", new Class[]{int.class});
                    socket = (BluetoothSocket) m.invoke(device, 1);
                    socket.connect();
                    Log.d("Bluetooth", "连接建立.");
                    //连接成功后开启读取该蓝牙设备数据的线程
                    new ReadThread(socket).start();
                }
            } catch (Exception e) {
                //socket连接失败
                try {
                    Method m = device.getClass().getMethod("createRfcommSocket", new Class[]{int.class});
                    socket = (BluetoothSocket) m.invoke(device, 1);
                    socket.connect();
                } catch (Exception e1) {
                    Log.e("Bluetooth", e1.toString()); 
                    try {
                        socket.close();
                    } catch (IOException ie) {
                    }
                }
                return;
            }
        }
    }

    //连接设备和读取数据都需要新启线程在子线程中进行，因为过程比较耗时，如果不在子线程影响效率和阻塞UI。
    //读写线程
    private class ReadThread extends Thread {

        private BluetoothSocket socket;

        public ReadThread(BluetoothSocket socket) {
            this.socket = socket;
        }

        @Override
        public void run() {
            byte[] buffer = new byte[1024];
            InputStream mmInStream = null;   //建立输入流读取数据

            try {
                mmInStream = socket.getInputStream();
                int num = mmInStream.read(buffer);
                while (num != -1 && isStop) {
                    num = mmInStream.read(buffer);
                    String str = new String(buffer);
                    String[] split = str.split("=");
                    StringBuffer stringBuffer = new StringBuffer(split[5]);
                    //获取流数据根据编码规则得到想要的数据
                    String s = stringBuffer.reverse().toString();
                    Log.e("Bluetooth", s);
                }

            } catch (IOException e1) {
                e1.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                if (mmInStream != null) {
                    try {
                        mmInStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

        }
    }

各种UUID链接：https://blog.csdn.net/weixin_40108380/article/details/105671120