I'm trying to implement domain event publishing from an entity by following the examples mentioned on the post below:
Example for @DomainEvents and @AfterDomainEventsPublication
However I haven't managed to have Spring calling my method annotated with @TransactionalEventListener.
See below the entity, service, event listener and test code:
@Entity
public class Book extends AbstractAggregateRoot<Book>
{
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
@Column(unique = true)
private String isbn;
@Column
private String name;
public Book(String isbn, String name)
{
this.isbn = isbn;
this.name = name;
}
public void purchase()
{
registerEvent(new BookPurchasedEvent(id));
}
// getters omitted for brevity
}
Service:
@Service
@Transactional
public class BookService
{
private final BookRepository bookRepository;
public BookService(BookRepository bookRepository)
{
this.bookRepository = bookRepository;
}
public void purchaseBook(Integer bookId)
{
Book book = bookRepository.findById(bookId)
.orElseThrow(NoSuchElementException::new);
book.purchase();
bookRepository.save(book);
}
}
Listener:
@Service
public class EventListener
{
private final Logger logger = LoggerFactory.getLogger(this.getClass());
@TransactionalEventListener
public void handleEvent(BookPurchasedEvent event)
{
logger.info("Received event {}", event);
}
}
Test:
@RunWith(SpringRunner.class)
@SpringBootTest
@Transactional
public class BookEventsTest
{
@Autowired
private BookService bookService;
@Autowired
private EntityManager entityManager;
@Test
public void test()
{
Book book = new Book("abcd-efgh", "El Quijote");
book = entityManager.merge(book);
bookService.purchaseBook(book.getId());
}
}
The log message from the listener is not logged. It works though when deployed as a REST service and invoked e.g. via Postman
Got it. Since my test is annotated with @Transactional, the transaction wrapping the test method will be rolled back. Therefore the method annotated with @TransactionalEventListener won't be called, since by default it triggers at the phase TransactionPhase.AFTER_COMMIT (and I'm not interested in having it called unless the transaction is successful). So the working version of the test looks as follows:
@RunWith(SpringRunner.class)
@SpringBootTest
public class BookEventsTest
{
@Autowired
private BookService bookService;
@Autowired
private BookRepository bookRepository;
@MockBean
private EventListener eventListener;
private Book book;
@Before
public void init() {
book = bookRepository.save(new Book("abcd-efgh", "El Quijote"));
}
@After
public void clean() {
bookRepository.deleteAll();
}
@Test
public void testService()
{
bookService.purchaseBook(book.getId());
then(eventListener)
.should()
.handleEvent(any(BookPurchasedEvent.class));
}
}