Event.java

    class OrderPlacedEvent {
        private Order order;
    }

    class ShopSellerService {

        @Inject
        private EventBus eventBus;

        public void sell(Order order) {
            order.toPlaced();

            eventBus.publish(new OrderPlacedEvent(order));
        }

    }

    class SmsNotifier {
        @Inject
        private EventBus eventBus;
        @Inject
        private SmsGateway smsGateway;

        @Listener
        public void listen(OrderPlacedEvent event) {
            Template message = TemplateFactory.createOrderPlacedMessage();

            /*
             * Infer destination customer and other variables for template
             */
            Message message = message.assign(event.getOrder());

            smsGateway.send(message);
        }


        @PostConstruct
        public void loaded() {

            /*
             * After the bean has been initialized we start listening for events on
             * event bus. There is no need to unsubscribe on PreDestroy because we
             * assume this will get called when the whole application is stopped -
             * this listener is application scoped.
             */
            eventBus.subscribe(this);
        }
    }

    class WarehouseJobUpdator {
        @Inject
        private EventBus eventBus;

        @Inject
        private JmsGateway jmsGateway;

        @Listener
        public void listen(OrderPlacedEvent event) {

            /*
             * Forward message to Warehouse JMS queue
             */
            jmsGateway.sendToWarehouse(event);
        }


        @PostConstruct
        public void loaded() {
            eventBus.subscribe(this);
        }
    }