Nested @Transactional methods with @Async

Question

I\'m using Spring with JPA. I have @EnableAsync and @EnableTransactionManagement turned on. In my user registration service method, I have a few other

Answer 1

Make a try by creating a new UserService class to manage user check, like so

@Override
@Transactional(propagation = Propagation.REQUIRES_NEW)
public User createOrUpdateUser(User newUser) {
    String username = newUser.getUsername();
    String email = newUser.getEmail();

    // ... Verify the user doesn't already exist

    // I have tried all manner of flushing and committing right here, nothing works
    newUser = userDAO.merge(newUser);
    return newUser;
}

then in the actual class, change

private User registerUser(User newUser, Boolean waitForAccount) {
    String username = newUser.getUsername();
    String email = newUser.getEmail();

    // ... Verify the user doesn't already exist

    // I have tried all manner of flushing and committing right here, nothing works
    newUser = userDAO.merge(newUser);

by

private User registerUser(User newUser, Boolean waitForAccount) {
    newUser = userService.createOrUpdateUser(newUser);

The new userService with @Transactional REQUIRES_NEW should force the commit and solve the issue.

Answer 2

With Vyncent's help, here is the solution that I arrived at. I created a new class called UserCreationService and put all of the method that handled User creation in that class. Here is an example:

@Override
public User registerUserWithProfileData(User newUser, String password, Boolean waitForAccount) {
    newUser.setPassword(password);
    newUser.encodePassword();
    newUser.setJoinDate(Calendar.getInstance(TimeZone.getTimeZone("UTC")).getTime());

    User registered = userService.createUser(newUser);
    registered = userService.processNewRegistration(registered, waitForAccount);

    return userService.setProfileInformation(registered);
}

You'll notice that there is NO @Transactional annotation on this method. This is on purpose. The corresponding createUser and processNewRegistration definitions look like this:

@Override
@Transactional(propagation = Propagation.REQUIRES_NEW)
public User createUser(User newUser) {
    String username = newUser.getUsername();
    String email = newUser.getEmail();

    if ((username != null) && (userDAO.getUserByUsername(username) != null)) {
        throw new EntityAlreadyExistsException("User already registered: " + username);
    }

    if (userDAO.getUserByUsername(newUser.getEmail()) != null) {
        throw new EntityAlreadyExistsException("User already registered: " + email);
    }

    return userDAO.merge(newUser);
}

@Override
@Transactional(propagation = Propagation.REQUIRES_NEW)
public User processNewRegistration(
        User newUser,
        Boolean waitForAccount) 
{
    Future<UserAccount> customer = paymentService.initializeForNewUser(newUser);
    if (waitForAccount) {
        try {
            customer.get();
        } catch (Exception e) {
            logger.error("Error while creating Customer object!", e);
        }
    }

    // Do some other maintenance type things...

    return newUser;
}

Vyncent was spot on that transaction management was the issue. Creating the other service allowed me to have better control over when those transactions committed. While I was hesitant to take this approach initially, that's the tradeoff with Spring managed transactions and proxies.

I hope this helps someone else save some time later.