Android client FirebaseApp initialization error

问题:

I had GCM implemented and I am trying to import GCM to FCM now. I dont want to use google-services.json because I want to use different google projects for different environments(Dev, Stag, Prod).

I tried to initialize the app via this code below

 FirebaseOptions.Builder options=new FirebaseOptions.Builder();
       options.setGcmSenderId("<<project id>>"); 
       options.setApplicationId("<<Project name>>"); 
       FirebaseApp firebaseApp = FirebaseApp.initializeApp(getApplicationContext(),options.build(),"MyTestFCM");
       String refreshedToken= FirebaseInstanceId.getInstance(firebaseApp).getToken();

I keep getting exception on Firebase App initialization

Caused by: java.lang.IllegalStateException: FirebaseApp with name [DEFAULT] doesn't exist. Available app names: MyTestFCM

If I remove the app name then i dont get a token back, then when I re-run the application I get a token. I have tried to execute the above piece of code from Mainactivity and Application class. In both places I get the same error.

So my question is how do I initialize Firebase application without using google-services.json

Thanks, P

回答1:

Firebase SDK requires to have a "default" project configured via google-services.json

Once you have that you can register FCM sdk with other sender-id using the FirebaseInstanceId.getInstance(context).getToken(...)

But please note that the most recent FCM features (auto-retry of the registration, topic subscriptions) only work with the default project.

回答2:

So turns out that you need to use google-services.json for FCM, and to handle multiple build variants situation,

1. Generate respective google-services.json from the firebase console for the different build variants.
2. Download the google-services.json
3. In your project create folders for the variants, for example if you want release build, create a folder with name "release" and place the google-services.json in it.

When the app builds, depending upon the build variant it looks for google-services.json in the respective folder and picks up the project details from it.

More details can be found on this thread google services issues 54

Thanks Arthur Thompson

回答3:

have you checked to make sure to set your FIREBASE_URL to the right string? Also did you make sure to have the appropriate app setup config?

Last time this happened, I needed to set up my Android App Configs. https://support.google.com/firebase/answer/7015592

Afterwards, you can follow this setup. https://firebase.google.com/docs/cloud-messaging/android/client

回答4:

Please do double check, you added

apply plugin: 'com.google.gms.google-services' at the bottom of app's gradle file and then clean and rebuild the project