Android app is not receiving FCM notification when closed

Question

I am checking Firebase Cloud Messaging to send notification. Have implemented it already and its receiving notification when app is in open state. But if I close app, its no longer gives notification. Is there any solution for this.

Code:

WebRequest wRequest;
wRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
wRequest.Method = "post";
wRequest.ContentType = " application/json;charset=UTF-8";
wRequest.Headers.Add(string.Format("Authorization: key={0}", AppId));

wRequest.Headers.Add(string.Format("Sender: id={0}", SenderId));

string postData = "{\"registration_ids\":[\"" + regIds + "\"], \"data\": "+ value +"}";

Byte[] bytes = Encoding.UTF8.GetBytes(postData);
wRequest.ContentLength = bytes.Length;

Stream stream = wRequest.GetRequestStream();
stream.Write(bytes, 0, bytes.Length);
stream.Close();

WebResponse wResponse = wRequest.GetResponse();

Messaging service-

public class MessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        Map<String, String>  data = remoteMessage.getData();
        sendNotification(data);
    }

    public void showMessage(Map<String, String>  serverData) {
        Intent i = new Intent(this,MainActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

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

        NotificationCompat.Builder builder = new NotificationCompat.Builder(this)
                .setAutoCancel(true)
                .setContentTitle(serverData.get("Title"))
                .setContentText(serverData.get("Message"))
                .setSmallIcon(R.drawable.common_google_signin_btn_icon_dark)
                .setContentIntent(pendingIntent);

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

        manager.notify(Integer.parseInt(serverData.get("ItemId")),builder.build());
    }

    private void sendNotification(Map<String, String>  serverData) {
        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_UPDATE_CURRENT);

        long[] pattern = {500,500,500,500,500};

        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);

        NotificationCompat.Builder notificationBuilder = (NotificationCompat.Builder) new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.common_google_signin_btn_icon_dark)
                .setContentTitle(serverData.get("Title"))
                .setContentText(serverData.get("Message"))
                .setAutoCancel(true)
                .setVibrate(pattern)
                .setLights(Color.BLUE,1,1)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(Integer.parseInt(serverData.get("ItemId")), notificationBuilder.build());
    }

}

Main activity-

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       FirebaseMessaging.getInstance().subscribeToTopic("test");
        FirebaseInstanceId.getInstance().getToken();
    }
}

Manifest-

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="test.com.firebasenotify">
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

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

    </application>

</manifest>

Answer 1

There's good solution and explanation about that issue here. You need to set high priority for notification to tell android react immediately, otherwise it takes couple of minutes to display received notification.

Answer 2

There was no issue with the code. I was using Mi note 4, and somehow it does not show notification in Mi4 when app is closed. I tested with other android device and its working fine.

Thanks to Tim Castelijns and Frank van Puffelen for participating in the conversation.