Bad notification for startForeground

Question

I created a service. And I started this service foreground, but when I lunch my application, An application is crashed. I added startServiceOreoCondition I read about this but it does not help me

@Override
public void onCreate() {

    mdb = ManagerDB.getInstance(getApplicationContext(), "name");
    context = getApplicationContext();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        nm.createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID_SERVICE, "*****", NotificationManager.IMPORTANCE_DEFAULT));
        nm.createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID_INFO, "********", NotificationManager.IMPORTANCE_DEFAULT));
    }

    startServiceOreoCondition();
    sp = getSharedPreferences("pfref", Activity.MODE_PRIVATE);
    editor = sp.edit();
    executeSomething();
    timer = new Timer();
    }




     private void startServiceOreoCondition() {
            if (Build.VERSION.SDK_INT >= 26) {

                String NOTIFICATION_CHANNEL_ID = "pl.***.***";
                String channelName = "Communication 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(context);
                Notification notification = notificationBuilder.setOngoing(true)
                        .setContentTitle(context.getString(R.string.app_name))
                        .setPriority(NotificationManager.IMPORTANCE_MIN)
                        .setCategory(Notification.CATEGORY_SERVICE)
                        .build();
                startForeground(4, notification);
            }else{
                startForeground(3, new Notification());
            }
        }

But When I lounch this application on andorid 8.1 i see this error :

android.app.RemoteServiceException: Bad notification for startForeground: java.lang.RuntimeException: invalid channel for service notification: Notification(channel=null pri=1 contentView=null vibrate=null sound=null defaults=0x0 flags=0x42 color=0x00000000 category=service vis=PRIVATE)

And also I added this permission :

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

Answer 1

NotificationChannel chan = new NotificationChannel(NOTIFICATION_CHANNEL_ID, channelName, NotificationManager.IMPORTANCE_NONE);
chan.setDescription(<Add channel Description>);

You have just created Notification Channel object But you need to create channel using channel object.

    nm.createNotificationChannel(new NotificationChannel(NOTIFICATION_CHANNEL_ID, "********", NotificationManager.IMPORTANCE_DEFAULT));

And while creating Notification Builder pass the created channel ID.

    NotificationCompat.Builder notificationBuilder = new 
    NotificationCompat.Builder(context,NOTIFICATION_CHANNEL_ID);
            Notification notification = notificationBuilder.setOngoing(true)
                    .setContentTitle(context.getString(R.string.app_name))
                    .setPriority(NotificationManager.IMPORTANCE_MIN)
                    .setCategory(Notification.CATEGORY_SERVICE)
                    .build();