Not receiving Firebase cloud push notifications in Android app

Question

I am not receiving push notification for my app. I have included the manifest files, the MainActivity file, the MyFireBaseMessagingService file and the build.gradle file and the googl-services.json. I really am stumped on what the issue could be. I go to Firebase composer to write message but nothing is received. I can hard code values in strings file and I receive a notification but I wanted something more dynamic. That is why I am trying to figure out how to send push notifications from FCM but I seem to be missing something or inputting something incorrectly.

MainAcitivity file

package com.example.testaaedapp;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.TaskStackBuilder;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.InstanceIdResult;

import java.net.URI;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private ImageButton logoButton;
    private ImageView blueButton, greenButton, orangeButton, yellowButton, redButton, darkBlueButton;
    public Button callButton;
    private final String CHANNEL_ID = "Alerts";
    private final int notificationId = 001;
    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        logoButton = findViewById(R.id.imageButton);
        logoButton.setOnClickListener(this);

        blueButton = findViewById(R.id.bluepuzzlepiece);
        blueButton.setOnClickListener(this);

        redButton = findViewById(R.id.redpuzzlepiece);
        redButton.setOnClickListener(this);

        greenButton = findViewById(R.id.greenpuzzlepiece);
        greenButton.setOnClickListener(this);

        orangeButton = findViewById(R.id.orangepuzzlepiece);
        orangeButton.setOnClickListener(this);

        yellowButton = findViewById(R.id.yellowpuzzlepiece);
        yellowButton.setOnClickListener(this);

        darkBlueButton = findViewById(R.id.darkbluepuzzlepiece);
        darkBlueButton.setOnClickListener(this);

        callButton = findViewById(R.id.button);
        callButton.setOnClickListener(this);

        displayNotification();
        // Get token
        // [START retrieve_current_token]
        FirebaseInstanceId.getInstance().getInstanceId()
                .addOnCompleteListener(new OnCompleteListener<InstanceIdResult>() {
                    @Override
                    public void onComplete(@NonNull Task<InstanceIdResult> task) {
                        if (!task.isSuccessful()) {
                            Log.w(TAG, "getInstanceId failed", task.getException());
                            return;
                        }

                        // Get new Instance ID token
                        String token = task.getResult().getToken();

                        // Log and toast
                        String msg = getString(R.string.msg_token_fmt, token);
                        Log.d(TAG, msg);
                        Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
                    }
                });
        // [END retrieve_current_token]

    }
        int requestCode = 0;
    public void onClick(View view) {

        if (view.getId() == R.id.button && ActivityCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
            Log.d("STATE", "Call Button DOES NOT WORK");
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CALL_PHONE}, requestCode);
            return;
        } else if (view.getId() == R.id.button && ActivityCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.CALL_PHONE) == PackageManager.PERMISSION_GRANTED) {
//            else if (view.getId() == R.id.button && ActivityCompat.checkSelfPermission(MainActivity.this,
//                    Manifest.permission.CALL_PHONE) == PackageManager.PERMISSION_GRANTED) {
            Log.d("STATE", "Call Button DOES WORK");
            Intent callIntent = new Intent(Intent.ACTION_CALL);
            callIntent.setData(Uri.parse("tel:[phone]"));
            startActivity(callIntent);


        } else {
            switch (view.getId()) {
                case R.id.imageButton:
                    setContentView(R.layout.activity_main);
                    break;

                case R.id.bluepuzzlepiece:

                    break;

                case R.id.redpuzzlepiece:
                    Intent blogIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.aaed.org/blog"));
                    startActivity(blogIntent);
                    break;

                case R.id.greenpuzzlepiece:
                    Intent videoIntent = new Intent(Intent.ACTION_VIEW);
                    videoIntent.setData(Uri.parse("https://www.youtube.com/channel/UCUwPShLvnCOTeQILvAtneOw"));
                    startActivity(videoIntent);
                    break;

                case R.id.yellowpuzzlepiece:
                    Intent secondActivity = new Intent(this, SecondActivity.class);
                    startActivity(secondActivity);
                    break;

                case R.id.orangepuzzlepiece:
                    Intent webIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.aaed.org"));
                    startActivity(webIntent);
                    break;

                case R.id.darkbluepuzzlepiece:
                    Intent schoolIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.aaed.org/online-course-content"));
                    startActivity(schoolIntent);


            }

        }

    }

    public void displayNotification () {
        createNotificationChannel();
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.drawable.ic_puzzlepieces)
                .setContentTitle("Test Message")
                .setContentText("This is text")
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setStyle(new NotificationCompat.BigTextStyle()
                        .bigText(getString((R.string.another_string))));

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);

        // notificationId is a unique int for each notification that you must define
        notificationManager.notify(notificationId, builder.build());
    }

    public void createNotificationChannel() {
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = getString(R.string.channel_name);
            String description = getString(R.string.channel_description);
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            /

/ Register the channel with the system; you can't change the importance
            // or other notification behaviors after this
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == requestCode)
        {
            if(grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                Intent callIntent = new Intent(Intent.ACTION_CALL);
                callIntent.setData(Uri.parse("tel:[phone]"));
                startActivity(callIntent);
            }
        }

MyFirebaseMessagingService file

package com.example.testaaedapp;

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.Build;
import android.util.Log;
import androidx.core.app.NotificationCompat;

import com.example.testaaedapp.MainActivity;
import com.example.testaaedapp.R;
import com.google.firebase.messaging.FirebaseMessagingService;

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    private static final String TAG = "MyFirebaseMsgService";

    // [START on_new_token]

    /**
     * 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.
     */
    @Override
    public void onNewToken(String token) {
        Log.d(TAG, "Refreshed token: " + token);

        // 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(token);
    }
    // [END on_new_token]

Manifest File

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testaaedapp">

    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality.
    -->
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps"></activity>
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_channel_id"
            android:value="AAED" />
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@drawable/ic_puzzlepieces" />
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_color"
            android:resource="@color/colorAccent" />

        <activity
            android:name=".MainActivity"
            android:label="Autism Academy"
            >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".SecondActivity"
            android:label="Locations"></activity>

        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />
        <!-- [START firebase_service] -->
        <service
            android:name=".MyFirebaseMessagingService"
            android:exported="false"
            android:enabled="true">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT" />
            </intent-filter>
        </service>


        <!-- [END firebase_service] -->
    </application>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <uses-permission android:name="android.permission.CALL_PHONE"></uses-permission>

</manifest>

Answer 1

I've had a similar issue. I've tried everything - in my opinion the main reason is that all the services are, sooner or later, being killed by the system. The only way is to make sure to deliver the notification to the system tray not to the application. To do that you need to use Data message notifications.

There are 2 types of FCM notifications: Notification message and Data message.

Data messages are delivered to system tray and are always display - even if service is not running.

Notification message looks like:

{
  "message":{
    "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",
    "notification":{
      "title":"Portugal vs. Denmark",
      "body":"great match!"
    }
  }
}

and triggers method OnMessageReceaved() of FirebaseMessagingService. Many devices (especially Huawei and Xiaomi) try to do everything to kill background services to prevent battery drain. So the FirebaseMessagingService isn't the best way to handle notifications.

Second type is Data message:

{
  "message":{
    "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",
    "data":{
      "Nick" : "Mario",
      "body" : "great match!",
      "Room" : "PortugalVSDenmark"
    }
  }
}

This type is handled by the system tray, so you don't need any of service running to get the notification. Its much more convenient method, but as far i know, it can't be achieved with the console.

You would probably need server API to send Data message.

Read this for more details.