Implementing Event Handling

public record OrderPlaced(
    UUID orderId, UUID customerId, Money total, Instant occurredAt) {}

@Service @RequiredArgsConstructor
public class OrderService {
    private final ApplicationEventPublisher events;
    @Transactional
    public Order place(Cart c) {
        var o = repo.save(Order.from(c));
        events.publishEvent(new OrderPlaced(o.id(), c.customerId(), o.total(), Instant.now()));
        return o;
    }
}

@Component
public class OrderEmailListener {
    @TransactionalEventListener(phase = AFTER_COMMIT)
    @Async
    public void on(OrderPlaced e) { mail.sendConfirmation(e.orderId()); }
}

public Order load(UUID id) {
    var order = new Order();
    eventStore.streamFor(id).forEach(order::apply);
    return order;
}