如何从android连接到最近的蓝牙低能耗设备？

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null || !bluetoothAdapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
bluetoothAdapter.startLeScan(mLeScanCallback);

private BluetoothAdapter.LeScanCallback mLeScanCallback =
        new BluetoothAdapter.LeScanCallback() {
    @Override
    public void onLeScan(final BluetoothDevice device, int rssi,
                         byte[] scanRecord) {
        // 处理扫描到的设备信息
    }
};

BluetoothDevice device = bluetoothAdapter.getRemoteDevice(deviceAddress);
BluetoothGatt gatt = device.connectGatt(context, false, gattCallback);

private BluetoothGattCallback gattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
        // 处理连接状态的变化
    }

    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        // 发现设备的服务
    }

    @Override
    public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
        // 读取特征值的回调
    }

    @Override
    public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
        // 写入特征值的回调
    }

    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        // 特征值变化的回调
    }
};