Attempt to invoke virtual method

[Basheer009]

getting this error: NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference
at :
private void startLiveData() {
if ((!this.liveDataActive) && (!this.BluetoothDeviceAddress.equals("")))
connectBluetoothDeviceAddress(this.BluetoothDeviceAddress);

}