r2dbc ItemService events

ItemService.java

@Service
@RequiredArgsConstructor
public class ItemService {

    private final NotificationService notificationService;

    ...

    /**
     * Listen to all saved items
     *
     * @return the saved items
     */
    public Flux<Item> listenToSavedItems() {

        return this.notificationService.listen(ITEM_SAVED, Item.class)
                .flatMap(this::loadRelations);
    }

    /**
     * Listen to all deleted items
     *
     * @return the ID of the deleted items
     */
    public Flux<Long> listenToDeletedItems() {

        return this.notificationService.listen(ITEM_DELETED, Item.class)
                .map(Item::getId);
    }

    ...

}