Android Version 8.1, Bad notification for startForeground

I have given my couple of days to solve this issue. My app is getting crash whose android version is 8.1. It is working perfectly fine in Android Version 8.0.

I followed the link mentioned below for the solution and tried many solutions given in this link but my application is not opening.

startForeground fail after upgrade to Android 8.1

I check the Android version in FirebaseMessageService class and create the channel for Oreo version but below given error is showing everytime

 android.app.RemoteServiceException: Bad notification for startForeground: java.lang.RuntimeException: invalid channel for service notification: Notification(channel=null pri=0 contentView=null vibrate=null sound=null defaults=0x0 flags=0x40 color=0x00000000 vis=PRIVATE)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1795)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:171)
        at android.app.ActivityThread.main(ActivityThread.java:6649)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)

Here below is my code. Please help me to rectify this problem

    public class MyFirebaseMessagingService extends FirebaseMessagingService
    {
        private NotificationManager notifManager;
        Context mContext;
        Random random = new Random();
        int m = random.nextInt(9999 - 1000) + 1000;

        @Override
        public void onMessageReceived(RemoteMessage remoteMessage) 
        {
           sendNotification();
        }



   public void sendNotification()
   {
   Intent intent = new Intent(this, Home.class);
   intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
   PendingIntent pendingIntent = PendingIntent.getActivity(this, m /* Request code */, intent, PendingIntent.FLAG_ONE_SHOT);

   String channelId = getString(R.string.default_notification_channel_id);
   Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
   NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, channelId)
                   .setSmallIcon(R.drawable.app_icon)
                   .setContentTitle("Logipace")
                   .setStyle(new NotificationCompat.BigTextStyle()
                           .bigText(message))
                   .setContentText(message)
                   .setAutoCancel(true)
                   .setSound(defaultSoundUri)
                   .setContentIntent(pendingIntent);
   notificationBuilder.setDefaults(Notification.DEFAULT_SOUND);

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

    // Since android Oreo notification channel is needed.
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
    {
        NotificationChannel channel = new NotificationChannel(channelId, "LOGIPACE", NotificationManager.IMPORTANCE_DEFAULT);
        notificationManager.createNotificationChannel(channel);
    }

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

    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
    startActivity(intent);
}
    }

Below is the code which I used in the onCreate() method of my Activity class.

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
        {
            // Create channel to show notifications.
            String channelId  = getString(R.string.default_notification_channel_id);
            String channelName = getString(R.string.default_notification_channel_name);
            NotificationManager notificationManager =
                    getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(new NotificationChannel(channelId,
                    channelName, NotificationManager.IMPORTANCE_LOW));
        }

Help me to resolve this issue.

You can use this for version Oreo and higher

if you use service class you can put this code

public class BlablaService extends Service 

    @Override
    public void onCreate(){
        super.onCreate();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
            startMyOwnForeground();
        else
            startForeground(1, new Notification());
    }

    private void startMyOwnForeground(){
        String NOTIFICATION_CHANNEL_ID = "com.example.simpleapp";
        String channelName = "My Background Service";
        NotificationChannel chan = new NotificationChannel(NOTIFICATION_CHANNEL_ID, channelName, NotificationManager.IMPORTANCE_NONE);
        chan.setLightColor(Color.BLUE);
        chan.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
        NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        assert manager != null;
        manager.createNotificationChannel(chan);

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
        Notification notification = notificationBuilder.setOngoing(true)
                .setSmallIcon(R.drawable.icon_1)
                .setContentTitle("App is running in background")
                .setPriority(NotificationManager.IMPORTANCE_MIN)
                .setCategory(Notification.CATEGORY_SERVICE)
                .build();
        startForeground(2, notification);
    } 

Of course don not forget ForeGroundService Permission your AndroidManifest.xml

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