从未调用过Android Firebase Cloud Messaging（FCM）onTokenRefresh（）并且getToken（）返回null

Question

I realize this question was raised before, but I have checked a substantial list of previous solutions and my problems mentioned in the subject remain.

Here's what I have:

1. MyFirebaseInstanceIDService class is almost straight out of the book:

    import android.util.Log; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.FirebaseUser; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.iid.FirebaseInstanceId; import com.google.firebase.iid.FirebaseInstanceIdService; public class MyFirebaseInstanceIDService extends FirebaseInstanceIdService { private static final String TAG = "MT: FIIDService"; @Override public void onTokenRefresh() { // Get updated InstanceID token. String refreshedToken = FirebaseInstanceId.getInstance().getToken(); Log.d(TAG, "Refreshed token: " + refreshedToken); sendRegistrationToServer(refreshedToken); } private void sendRegistrationToServer(String token) { FirebaseAuth mAuth = FirebaseAuth.getInstance(); FirebaseUser user = mAuth.getCurrentUser(); if (user != null) { FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference IDTokensRef = database.getReference(getString(R.string.firebase_idtokens)); IDTokensRef.child(user.getUid()).setValue(token); Log.d(TAG, "Refreshed token assigned to user: " + user.getDisplayName()); } } 

2. The service declared in the manifest (within the application clause), copied from the Firebase pages. Also, I have no "tools:node="merge" in the manifest, which solved the issue for some other people.

    <service android:name=".MyFirebaseInstanceIDService"> <intent-filter> <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/> </intent-filter> </service> 

3. All the latest dependencies in the app level build.gradle:

    dependencies { implementation 'com.android.support.constraint:constraint-layout:1.1.0-beta4' implementation 'com.github.bumptech.glide:glide:3.7.0' implementation 'com.android.support:appcompat-v7:27.0.2' implementation 'com.android.support:design:27.0.2' implementation 'com.android.support:support-v4:27.0.2' implementation 'com.android.support:support-annotations:27.0.2' implementation 'com.android.support:palette-v7:27.0.2' implementation 'com.google.firebase:firebase-core:11.8.0' implementation 'com.google.firebase:firebase-auth:11.8.0' implementation 'com.google.firebase:firebase-storage:11.8.0' implementation 'com.google.firebase:firebase-database:11.8.0' implementation 'com.google.firebase:firebase-messaging:11.8.0' implementation 'com.firebaseui:firebase-ui-storage:1.0.1' implementation 'com.google.android.gms:play-services-ads:11.8.0' } apply plugin: 'com.google.gms.google-services' 

4. The latest google services defined in the project level build.gradle :

    buildscript { repositories { jcenter() google() } dependencies { classpath 'com.android.tools.build:gradle:3.0.1' classpath 'com.google.gms:google-services:3.1.1' // Added when setting up Firebase } } allprojects { repositories { jcenter() google() maven { url "https://maven.google.com" name 'Google' } } } 

5. To be sure, I have downloaded the google-services.json once again to the app folder, without any effect. Finally, I declare INTERNET and ACCESS_NETWORK_STATE permissions in the manifest.

I have had a similar app working in the past, so I know my setup should work. But somehow, even after uninstalling/reinstalling the app, both in the emulator (tried several types and API 25 & 26 versions) as well as on a real device, onTokenRefresh in the InstanceIDService is never called, and FirebaseInstanceId.getInstance().getToken() returns null, in any relevant class of my application.

It also does not seem to be a timing issue related to obtaining a token: I receive null both immediately after user signs on, and still, do just before signing off.

My basic question is: are there ways to debug/investigate the token problem? In logcat I do not see any indications that there is a Firebase problem.

Answer 1

I have found out that occurrence of the problem depends on the firebase SDK version that is specified in the app level build.gradle : onTokenRefresh is no longer called as of SDK version 11.6.0. Looking at the release notes, this version has the following change related to token generation:

"Improved FCM token fetch logic so that the FCM token is now created faster and with less battery drain."

I assume that the FCM related changes in this release are related to my problem, and will issue a bug report.

Update : Firebase Support investigated the problem and reported back that the origin of the problem was the following lines in my AndroidManifest:

<uses-permission
    android:name="android.permission.WAKE_LOCK"
    tools:node="remove"/>

which I once added to avoid requesting "prevent phone from sleeping permission". Without these lines in the manifest the FCM token is refreshed without issues in combination with SDK 11.8.0.