Transaction与EventListener

Spring事务与ApplicationEventPublisher

@Transactional
public void handle() {
    var account = Account.builder()
            .username("huhx")
            .password("pass")
            .build();
    accountRepository.save(account);
    publisher.publishEvent(new AccountEvent("huhx"));
    var account2 = Account.builder()
            .username("huhx2")
            .password("pass2")
            .build();
    accountRepository.save(account2);
}

@Component
@RequiredArgsConstructor
public class AccountEventHandler {

    private final BookService bookService;

    @EventListener(AccountEvent.class)
    public void onAccountEvent(AccountEvent event) {
        bookService.save(new BookRequest(event.username()));

        throw new RuntimeException();
    }
}

// 1. No books saved, no account saved

// 2. add @Transactional on onAccountEvent, No books saved, no account saved

// 3. add @Async on onAccountEvent, two accounts saved, one book saved

// 4. add @Async and @Transactional on onAccountEvent, only two accounts saved

// 5. execute in Thread and with @Transactional, two accounts saved, one book saved(这里加不加@Transactional，没区别)
@Transactional
@EventListener(AccountEvent.class)
public void handle(AccountEvent event) {
    new Thread(() -> {
        bookService.save(new BookRequest(event.username()));
        throw new RuntimeException();
    }).start();
}

// 6. change the eventHandle code as following, no accounts saved, only one book saved(这里加不加@Transactional，没区别)
@Transactional
@EventListener(AccountEvent.class)
public void handle(AccountEvent event) {
    new Thread(() -> bookService.save(new BookRequest(event.username()))).start();
    bookService.save(new BookRequest(event.username()));
    throw new RuntimeException();
}

默认情况下，ApplicationEventPublisher的publishEvent方法是同步的