Unresolved class 'MyFirebaseMessagingService'

Question

I'm following the tutorial on Setting up a Firebase Cloud Messaging client app on Android which involves adding a <service> component to AndroidManifest.xml.

<service android:name=".java.MyFirebaseMessagingService">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

However, I'm getting Unresolved class MyFirebaseMessagingService. Where exactly do I import that class from?

NOTE: I'm writing in Kotlin

Answer 1

On the same link that you have provided, it is mentioned that you need to add a service class in your project and declare it in your AndroidManifest.xml like this:

<service android:name=".java.MyFirebaseMessagingService">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

So basically these are the steps that you need to follow:

1. Inside your package where you have kept Java classes, create a class called MyFirebaseMessagingService (you can choose any name)
2. Declare it in AndroidManifest.xml as shown above.

3. This class which you have defined in step 1 above, will extend FirebaseMessagingService, therefore it will have a method called onMessageReceived, that you will have to override, as shown below:

      @Override
       public void onMessageReceived(RemoteMessage remoteMessage) {
           // ...
   
       // TODO(developer): Handle FCM messages here.
       Log.d(TAG, "From: " + remoteMessage.getFrom());
   
       // Check if message contains a data payload.
       if (remoteMessage.getData().size() > 0) {
           Log.d(TAG, "Message data payload: " + remoteMessage.getData());
   
           if (/* Check if data needs to be processed by long running job */ true) {
               // For long-running tasks (10 seconds or more) use Firebase Job Dispatcher.
               scheduleJob();
           } else {
               // Handle message within 10 seconds
               handleNow();
           }
   
       }
   
       // Check if message contains a notification payload.
       if (remoteMessage.getNotification() != null) {
           Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
       }
   
       // Also if you intend on generating your own notifications as a result of a received FCM
       // message, here is where that should be initiated. See sendNotification method below.
   }
   

If you are writing code in Kotlin, then you need to name your class as MyFirebaseMessagingService.kt and then create a class and put below code. This is also mentioned on that link itself.

override fun onMessageReceived(remoteMessage: RemoteMessage?) {
// ...

// TODO(developer): Handle FCM messages here.
Log.d(TAG, "From: ${remoteMessage?.from}")

// Check if message contains a data payload.
remoteMessage?.data?.isNotEmpty()?.let {
    Log.d(TAG, "Message data payload: " + remoteMessage.data)

    if (/* Check if data needs to be processed by long running job */ true) {
        // For long-running tasks (10 seconds or more) use Firebase Job Dispatcher.
        scheduleJob()
    } else {
        // Handle message within 10 seconds
        handleNow()
    }
}

// Check if message contains a notification payload.
remoteMessage?.notification?.let {
    Log.d(TAG, "Message Notification Body: ${it.body}")
}

// Also if you intend on generating your own notifications as a result of a received FCM
// message, here is where that should be initiated. See sendNotification method below.
}