com.google.firebase.database.DatabaseException: Serializing Arrays is not supported, please use Lists instead

Question

I am trying to persist a custom object using the following code:

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();
Databas         


        

Answer 1

I've managed to find the reason causing this crash. I installed the app on another device running Android 5.x and Firebase threw a much less confusing exception there:

com.google.firebase.database.DatabaseException: No properties to serialize found on class android.graphics.Paint$Align

It appeared that Firebase (unlike Gson) tries to serialize all possible getters even though they don't have direct connection with global variables (class members / fields), in my particular case one of my objects contained a method returning Drawable - getDrawable(). Obviously, Firebase doesn't know how to convert drawable into json.

Interesting moment (probably a bug in Firebase SDK): on my older device running Android 4.4.1 I still get my original exception in the same project and configuration:

Caused by: com.google.firebase.database.DatabaseException: Serializing Arrays is not supported, please use Lists instead