在 Firebase 控制台中设置后，Android 计划通知未显示

Question

I am learning how to send periodic notification into my android app from my Firebase console:

Homepage.java :

protected void onCreate(@Nullable Bundle savedInstanceState) {            

  startService(new Intent(getApplicationContext(),firebase_connection.class)); 
 //Here I am calling the service class
        
}

---

firebase_connection.java :

public class firebase_connection extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(@NonNull RemoteMessage message) {
        super.onMessageReceived(message);
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel("MyNotifications","MyNotifications", NotificationManager.IMPORTANCE_DEFAULT);
            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(channel);
        }
        FirebaseMessaging.getInstance().subscribeToTopic("electric").addOnCompleteListener(new OnCompleteListener<Void>() {
            @Override
            public void onComplete(@NonNull Task<Void> task) {
                String msg = "Welcome to my app";
                if(!task.isSuccessful())
                    msg = "Sorry";
                Toast.makeText(getApplicationContext(),msg,Toast.LENGTH_SHORT).show();
            }
        });
    }
}

My Firebase console :

This is my scheduled notification

---

I kept waiting till 9:40 AM (as set in my notifications settings given int the above screenshot) and no notification showed up. I am new to Firebase, where am I going wrong? Please help me.

I am running the app on an actual device

Answer 1

There is a bunch of stuff you are missing. Firstly, you have to declare FirebaseMessagingService inside AndroidManifest like this within application tag:

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

And instead of calling startService in onCreate method, you have to subscribe to topic. Right now, you are subscribing in the notification service itself which is completely wrong.

protected void onCreate(@Nullable Bundle savedInstanceState) {            
  FirebaseMessaging.getInstance().subscribeToTopic("electric").addOnCompleteListener(new OnCompleteListener<Void>() {
       @Override
       public void onComplete(@NonNull Task<Void> task) {
           String msg = "Welcome to my app";
           if(!task.isSuccessful())
               msg = "Sorry";
           Toast.makeText(getApplicationContext(),msg,Toast.LENGTH_SHORT).show();
       }
   });
}

Finally, in the FirebaseMessagingService , you are just creating a notification channel but not creating a notification itself. Do it like this:

public class firebase_connection extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(@NonNull RemoteMessage message) {
        super.onMessageReceived(message);

        NotificationManager manager = getSystemService(NotificationManager.class);

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel("channel1","My Notification", NotificationManager.IMPORTANCE_DEFAULT);
            channel.setDescription("description");
            manager.createNotificationChannel(channel);
        }
        
        if (remoteMessage.getNotification() != null) {
            Notification notification = NotificationCompat.Builder(context, "channel1")
            .setSmallIcon(R.drawable.ic_launcher_foreground)
            .setContentTitle(message.getNotification().getTitle())
            .setContentText(message.getNotification().getBody())
            .build();

             manager.notify(1, notification)
        }
    }
}

And you can use RemoteMessage object to fetch the title and the text you sent from the Firebase Console like above. Hope it works out!