如何使用Android蓝牙API对BLE GATT交换进行计时？

BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter bluetoothAdapter = bluetoothManager.getAdapter();

if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE) || bluetoothAdapter == null) {
    // 设备不支持BLE
    return;
}

BluetoothLeScanner bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
ScanCallback scanCallback = new ScanCallback() {
    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        // 处理扫描到的设备
        BluetoothDevice device = result.getDevice();
        // 连接到设备
        device.connectGatt(context, false, gattCallback);
    }
};

bluetoothLeScanner.startScan(scanCallback);

BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        if (newState == BluetoothProfile.STATE_CONNECTED) {
            // 连接成功，发现服务
            gatt.discoverServices();
        } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
            // 连接断开
        }
    }

    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        if (status == BluetoothGatt.GATT_SUCCESS) {
            // 发现服务成功，可以进行数据交换
            BluetoothGattService service = gatt.getService(serviceUuid);
            BluetoothGattCharacteristic characteristic = service.getCharacteristic(characteristicUuid);

            // 启用通知
            gatt.setCharacteristicNotification(characteristic, true);

            // 设置Characteristic的描述符
            BluetoothGattDescriptor descriptor = characteristic.getDescriptor(descriptorUuid);
            descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
            gatt.writeDescriptor(descriptor);
        }
    }

    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        // 收到Characteristic的通知数据，进行计时操作
    }
};