Send Notification for Android O and Lower

NotificationDemo.txt

    private static final String NOTIFICATION_CHANNEL_ID = "1001";
    private static final int NOTIFICATION_ID = 1001;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_demo);

        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
                NotificationChannel notificationChannel =
                        new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_DEFAULT);
                // Configure the notification channel.
                notificationChannel.setDescription("My Notification Description.");
                notificationChannel.enableLights(true);
                notificationChannel.setLightColor(Color.RED);
                notificationManager.createNotificationChannel(notificationChannel);

                // notification.defaults = Notification.DEFAULT_LIGHTS | Notification.DEFAULT_VIBRATE;

                NotificationCompat.Builder builder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID)
                        .setSmallIcon(R.drawable.ic_save)
                        .setContentTitle(getString(R.string.app_name))
                        .setContentText("My Notification Description.");

                notificationManager.notify(NOTIFICATION_ID, builder.build());
            } else {
                final Intent intent = new Intent(this, MainActivity.class);
                PendingIntent contentIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

                NotificationCompat.Builder b = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);

                b.setAutoCancel(true)
                        .setDefaults(Notification.DEFAULT_ALL)
                        .setWhen(System.currentTimeMillis())
                        .setSmallIcon(R.drawable.ic_save)
                        .setTicker("Success")
                        .setContentTitle(getString(R.string.app_name))
                        .setContentText("My Notification Description")
                        .setDefaults(Notification.DEFAULT_LIGHTS | Notification.DEFAULT_SOUND)
                        .setContentIntent(contentIntent)
                        .setContentInfo("Image");

                NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
                notificationManager.notify(NOTIFICATION_ID, b.build());

            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }