Android notifications when app is in background

I am sending push notification from google firebase for my android app with target of Android 5.0:

My push notification code is:

@Override
public void onMessageReceived(RemoteMessage remoteMessage) {
    String badge = "0";
    Uri uri = Uri.parse(
            getString(R.string.app_host_name)
    );

    Map<String, String> data = remoteMessage.getData();
    if (data.size() > 0) {
        try {
            uri = Uri.parse(
                    data.get("link")
            );

            badge = data.get("badge");
        } catch (NullPointerException e) {
            //
        }
    }

    if (remoteMessage.getNotification() != null) {
        RemoteMessage.Notification notification = remoteMessage.getNotification();
        sendNotification(notification.getTitle(), notification.getBody(), uri.toString(), badge);
    }
}



private void sendNotification(String title, String body, String url, String badge) {
    Intent intent = new Intent(this, MainActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

    if (Patterns.WEB_URL.matcher(url).matches()) {
        intent.putExtra("link", url);
    }

    PendingIntent pendingIntent = PendingIntent.getActivity(
            this,
            0,
            intent,
            PendingIntent.FLAG_UPDATE_CURRENT
    );

    Resources resources = getApplicationContext().getResources();

    NotificationCompat.Builder notificationBuilder =
            new NotificationCompat.Builder(this, "default")
                    .setColor(
                            resources.getColor(R.color.colorPrimaryDark)
                    )
                    .setSmallIcon(
                            R.drawable.ic_stat_icon
                    )
                    .setContentTitle(title)
                    .setContentText(body)
                    .setAutoCancel(true)
                    .setNumber(Integer.parseInt(badge))
                    .setLargeIcon(
                            BitmapFactory.decodeResource(
                                    resources,
                                    R.mipmap.ic_launcher
                            )
                    )
                    .setContentIntent(pendingIntent);

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

    if (Build.VERSION.SDK_INT >= 26) {
        NotificationChannel notificationChannel = new NotificationChannel(
                "default",
                "Main notification channel",
                NotificationManager.IMPORTANCE_HIGH
        );

        notificationManager.createNotificationChannel(
                notificationChannel
        );
    }

    notificationManager.notify(
            1,
            notificationBuilder.build()
    );
}

And everything is super perfect when application is active/opened/not in background, but when it is not, notifications are not grouped, there is no number displayed, and no reaction on all of this settings at all, what i was able to change is only small icon and circle color via manifest settings

    <meta-data
        android:name="com.google.firebase.messaging.default_notification_icon"
        android:resource="@drawable/ic_stat_icon" />
    <meta-data
        android:name="com.google.firebase.messaging.default_notification_color"
        android:resource="@color/colorPrimaryDark" />

but why? It's like when app is in background notifications are not using settings from Activity code but using only some kind of "default" one from AndroidManifest.

As you said in the comments:

when app is on background, app isn't taking setNumber, setAutoCancel, setSmallIcon, setLargeIcon options

It is because you are using notification payload to send the notification which only triggers on the foreground.

So when your app is in the background it does not enter this method.

to solve this you can use data payload alone:

"data": {
"titles": "New Title",
"bodys": "body here"
}

since the data payload will enter the onMessageReceived() when your app is in foreground/background.

then in fcm you can do this:

  if (remoteMessage.getData().size() > 0) {

        title = remoteMessage.getData().get("titles");
        body = remoteMessage.getData().get("bodys");
    }