Utilizado no artigo O job dos Jobs - JobServices https://medium.com/@rosariopfernandes/job2-fbf022368795

NotificationJobService.java

public class NotificationJobService extends JobService{

    private final String TAG = NotificationJobService.class.getSimpleName();
    private AsyncTask backgroundTask;

    @Override
    public boolean onStartJob(JobParameters job) {
        //Executar todo trabalho no background
        backgroundTask = new AsyncTask()
        {
            @Override
            protected Object doInBackground(Object[] objects){
                //Executar qualquer trabalho que for necessário
                return null;
            }

            @Override
            protected void onPostExecute(Object o)
            {
                notificar("Olha Que Novidade","Já sei utilizar JobServices!")
                jobFinished(job, false);
            }
        };
        mBackgroundTask.execute();
        return true; //Ainda há algo a ser executado?
        //Retornamos true porque o trabalho ainda está sendo executado dentro
        //do AsyncTask.
        //Se fosse uma operação mais simples retornavamos false.
    }

    private void notificar(String title, String text)
    {
        NotificationCompat.Builder notification =
                new NotificationCompat.Builder(getApplicationContext());
        notification.setStyle(new NotificationCompat.BigTextStyle());
        notification.setSmallIcon(R.drawable.icon);
        notification.setContentText(text);
        notification.setContentTitle(title);
        notification.setPriority(NotificationCompat.PRIORITY_MIN);
        notification.setAutoCancel(true);
        Intent update = new Intent(Intent.ACTION_VIEW);
        TaskStackBuilder stackBuilder1 = TaskStackBuilder.create(getApplicationContext());
        stackBuilder1.addNextIntent(update);
        PendingIntent updateIntent = stackBuilder1.getPendingIntent(0,
                PendingIntent.FLAG_UPDATE_CURRENT);
        notification.setContentIntent(updateIntent);
        NotificationManagerCompat.from(getApplicationContext())
                .notify(100, notification.build());
    }

    @Override
    public boolean onStopJob(JobParameters job) {
        return false;//Tentar novamente?
    }

}