How to solve the problem about firebase tokens?

Question

Android

Hello, I had some error: on some versions of api, mostly old ones, the application crashes, complains about this line, where I connect to the firebase database to save information on the user's registration token:

databaseReference = FirebaseDatabase.getInstance().getReference(FirebaseInstanceId.getInstance().getToken());

writes that

Argument 'FirebaseInstanceId.getInstance().getToken()' might be null

As I understand it, at the moment the program accesses this line, databaseRefernce returns an empty value, please tell me how to solve the problem?

Answer 1

I had to add a simple check:

String token = FirebaseInstanceId.getInstance().getToken();
        if (token == null) return;
        databaseReference = FirebaseDatabase.getInstance().getReference(token);