How to ensure that the Firebase Messaging sample i

Question

When I build and run the Firebase Messaging Sample app (after obtaining and installing a custom google-services.json file from my Firebase Console, as described by the wizard within Android Studio), I can send a simple non-notification message to it with my test script, and it works.

... but only if the app has been started on the device.

If I fail to first start the app, or force-stop the app (from Settings | Apps) after it's been started, the message doesn't quite seem to get through. (I say that because I no longer see any logging output from my onMessageReceived method).

Some have reported that when a message is sent out, their app wakes up even if their app has not first been started -- which is great! Exactly what I want!

But I haven't been able to figure out what they're doing to make that happen.

What am I missing? How should I change this code to make sure that it receives the message even when the app has not been started, or after the app has been forcibly stopped?

Note: the code I'm running (below) is based very closely upon the Firebase Quickstarts for Android code which can be downloaded and built from within Android Studio (File | New | Import Sample ... and then find "Firebase Quickstarts for Android" within the list it populates). (I believe that Google hosts that same code on GitHub here: github.com/firebase/quickstart-android/tree/master/messaging‌​). I modified the logging output and comments slightly.

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.google.firebase.quickstart.fcm">

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme">
    <!-- [START fcm_default_icon] -->
    <!-- Set custom default icon. This is used when no icon is set for incoming notification messages. -->
    <meta-data
        android:name="com.google.firebase.messaging.default_notification_icon"
        android:resource="@drawable/ic_stat_ic_notification" />
    <!-- Set color used with incoming notification messages. This is used when no color is set for the incoming
         notification message. -->
    <meta-data
        android:name="com.google.firebase.messaging.default_notification_color"
        android:resource="@color/colorAccent" />
    <!-- [END fcm_default_icon] -->
    <activity
        android:name="com.google.firebase.quickstart.fcm.MainActivity"
        android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.LAUNCHER"/>
        </intent-filter>
    </activity>

    <!-- [START firebase_service] -->
    <service
        android:name=".MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT"/>
        </intent-filter>
    </service>
    <!-- [END firebase_service] -->
    <!-- [START firebase_iid_service] -->
    <service
        android:name=".MyFirebaseInstanceIDService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT"/>
        </intent-filter>
    </service>
    <!-- [END firebase_iid_service] -->
    <service android:name=".MyJobService"
             android:exported="false">
        <intent-filter>
            <action android:name="com.firebase.jobdispatcher.ACTION_EXECUTE"/>
        </intent-filter>
    </service>
</application>

MyFirebaseInstanceIDService.java

public class MyFirebaseInstanceIDService extends FirebaseInstanceIdService {

    private static final String TAG = "MyFirebaseIIDService";

    /**
     * Called if InstanceID token is updated. This may occur if the security of
     * the previous token had been compromised. Note that this is called when the InstanceID token
     * is initially generated so this is where you would retrieve the token.
     */
    // [START refresh_token]
    @Override
    public void onTokenRefresh() {
        // Get updated InstanceID token.
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
        Log.d(TAG, "Refreshed token: " + refreshedToken);

        // If you want to send messages to this application instance or
        // manage this apps subscriptions on the server side, send the
        // Instance ID token to your app server.
        sendRegistrationToServer(refreshedToken);
    }
    // [END refresh_token]

    /**
     * Persist token to third-party servers.
     *
     * Modify this method to associate the user's FCM InstanceID token with any server-side account
     * maintained by your application.
     *
     * @param token The new token.
     */
    private void sendRegistrationToServer(String token) {
        // TODO: Implement this method to send token to your app server.
    }
}

MyFirebaseMessagingService.java

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    private static final String TAG = "MyFirebaseMsgService";

    /**
     * Called when message is received.
     *
     * @param remoteMessage Object representing the message received from Firebase Cloud Messaging.
     */
    // [START receive_message]
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // [START_EXCLUDE]
        // There are two types of messages data messages and notification messages. Data messages are handled
        // here in onMessageReceived whether the app is in the foreground or background. Data messages are the type
        // traditionally used with GCM. Notification messages are only received here in onMessageReceived when the app
        // is in the foreground. When the app is in the background an automatically generated notification is displayed.
        // When the user taps on the notification they are returned to the app. Messages containing both notification
        // and data payloads are treated as notification messages. The Firebase console always sends notification
        // messages. For more see: https://firebase.google.com/docs/cloud-messaging/concept-options
        // [END_EXCLUDE]

        // TODO(developer): Handle FCM messages here.
        Log.d(TAG, "onMessageReceived: From: " + remoteMessage.getFrom());

        // Check if message contains a data payload.
        if (remoteMessage.getData().size() > 0) {
            Log.d(TAG, "onMessageReceived: 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, "onMessageReceived: 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.
    }
    // [END receive_message]

    /**
     * Schedule a job using FirebaseJobDispatcher.
     */
    private void scheduleJob() {
        // [START dispatch_job]
        FirebaseJobDispatcher dispatcher = new FirebaseJobDispatcher(new GooglePlayDriver(this));
        Job myJob = dispatcher.newJobBuilder()
                .setService(MyJobService.class)
                .setTag("my-job-tag")
                .build();
        dispatcher.schedule(myJob);
        // [END dispatch_job]
    }

    /**
     * Handle time allotted to BroadcastReceivers.
     */
    private void handleNow() {
        Log.d(TAG, "Short lived task is done.");
    }

    /**
     * Create and show a simple notification containing the received FCM message.
     *
     * @param messageBody FCM message body received.
     */
    private void sendNotification(String messageBody) {
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
                PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.ic_stat_ic_notification)
                .setContentTitle("FCM Message")
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.notify(0 /* ID of notification */, notificationBuilder.build());
    }
}

bash test script

curl -X POST \
--Header "Authorization: key=<server key from Firebase Console>“ \
--Header "Content-Type: application/json" \
https://fcm.googleapis.com/fcm/send  \
-d " \
    { \
        \"to\”:\”<token returned by FirebaseInstanceId.getInstance().getToken()>\”, \
        \"priority\": \"high\" \
    }"
echo 

Answer 1

The behavior you are observing is the result of the app being in the "Stopped State". This behavior was introduced in Android 3.1 and is described here in the section Launch controls on stopped applications:

Applications are in a stopped state when they are first installed but are not yet launched and when they are manually stopped by the user (in Manage Applications)

When an app is in Stopped state, the system will not deliver Broadcast intents to it, which means it will not receive Firebase messages. As far as I know, you can't get around this; the user must start the app for the first time. This tells the system that the user wants the app to be operational and it is safe to deliver Broadcast intents to it.

Here are some SO questions/answers related to Stopped State.