startForeground fail after upgrade to Android 8.1

After some tinkering for a while with different solutions i found out that one must create a notification channel in Android 8.1 and above.

private fun startForeground() {    val channelId =            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {                createNotificationChannel("my_service", "My Background Service")            } else {                // If earlier version channel ID is not used                // https://developer.android.com/reference/android/support/v4/app/NotificationCompat.Builder.html#NotificationCompat.Builder(android.content.Context)                ""            }    val notificationBuilder = NotificationCompat.Builder(this, channelId )    val notification = notificationBuilder.setOngoing(true)            .setSmallIcon(R.mipmap.ic_launcher)            .setPriority(PRIORITY_MIN)            .setCategory(Notification.CATEGORY_SERVICE)            .build()    startForeground(101, notification)}@RequiresApi(Build.VERSION_CODES.O)private fun createNotificationChannel(channelId: String, channelName: String): String{    val chan = NotificationChannel(channelId,            channelName, NotificationManager.IMPORTANCE_NONE)    chan.lightColor = Color.BLUE    chan.lockscreenVisibility = Notification.VISIBILITY_PRIVATE    val service = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager    service.createNotificationChannel(chan)    return channelId}

From my understanding background services are now displayed as normal notifications that the user then can select to not show by deselecting the notification channel.

Update:Also don't forget to add the foreground permission as required Android P:

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

Java Solution (Android 9.0, API 28)

In your Service class, add this:

@Overridepublic 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);}

UPDATE: ANDROID 9.0 PIE (API 28)

Add this permission to your AndroidManifest.xml file:

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

The first answer is great only for those people who know kotlin, for those who still using java here I translate the first answer

 public Notification getNotification() {        String channel;        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)            channel = createChannel();        else {            channel = "";        }        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, channel).setSmallIcon(android.R.drawable.ic_menu_mylocation).setContentTitle("snap map fake location");        Notification notification = mBuilder                .setPriority(PRIORITY_LOW)                .setCategory(Notification.CATEGORY_SERVICE)                .build();        return notification;    }    @NonNull    @TargetApi(26)    private synchronized String createChannel() {        NotificationManager mNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);        String name = "snap map fake location ";        int importance = NotificationManager.IMPORTANCE_LOW;        NotificationChannel mChannel = new NotificationChannel("snap map channel", name, importance);        mChannel.enableLights(true);        mChannel.setLightColor(Color.BLUE);        if (mNotificationManager != null) {            mNotificationManager.createNotificationChannel(mChannel);        } else {            stopSelf();        }        return "snap map channel";    } 

For android, P don't forget to include this permission

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