Spring Boot @Transactional not working when on @Service class (instead of controller)

Question

I thought it was best practice to put the @Transactional annotation on the service layer classes and not on the controllers (see f.e. Why we shouldn't make a Spring MVC controller @Transactional?). But this not working on my Spring Boot application. Why is that?

The registerAction method in the controller (see code below) performs multiple service calls. When f.e. the mailService.sendActivationMail(...) fails, I want to rollback the inserted user from the userService.registerUser(...) call. Do I need to put the @Transactional annotation on the controller class or not?

My Spring Boot application correctly uses transactions when the @Transactional annotation is set on the controller class:

AuthController.java

@RestController
@RequestMapping("/api/auth")
@Transactional
public class AuthController {

    @Autowired
    private UserService userService;

    @Autowired
    private ProfileService profileService;

    @Autowired
    private MailService mailService;

    @RequestMapping(path = "register", method = RequestMethod.POST)
    public Profile registerAction(@Valid @RequestBody Registration registration) {
        ApiUser user = userService.registerUser(registration);
        Profile profile = profileService.createProfile(user, registration);

        mailService.sendActivationMail(user);

        return profile;
    }

}

but transactions don't work when the @Transactional annotation is set on the Service classes instead (and not on the controller):

UserService.java

@Service
@Transactional
public class UserService {

    @Autowired
    private ApiUserRepository userRepository;

    public ApiUser registerUser(Registration registration) {
        ...
        userRepository.save(user);
        ...
    }

}

---

My configuration classes:

SpringApiApplication.java

@SpringBootApplication
public class SpringApiApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringApiCommonApplication.class, args);
    }
}

ApiConfiguration.java

@Configuration
@EnableJpaAuditing
@EnableTransactionManagement
public class ApiConfiguration {
    @Autowired
    private ApiProperties properties;

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    public UsernameCanonicalizer usernameCanonicalizer() {
        return new UsernameCanonicalizer();
    }

    @Bean
    public EmailCanonicalizer emailCanonicalizer() {
        return new EmailCanonicalizer();
    }

    @Bean
    public ApiTokenHandler activationTokenHandler() {
        return new StandardApiTokenHandler(properties.getActivationTokenDuration());
    }
}

Answer 1

@M.Deinum got me on the right track. Spring (boot) doesn't automatically wrap your controller calls in a transaction like other frameworks do. So you have to either add a @Transactional annotation to your controller, or move the code from the controller class to a service class.

Moving the code from the controller class to a service class is the better thing to do since (amongst other things) makes the code better testable. So that's what I did.

AuthenticationService.java

@Service
public class AuthenticationService {
    @Autowired
    private UserManager userManager;

    @Autowired
    private ProfileManager profileManager;

    @Autowired
    private MailManager mailManager;

    @Transactional
    public Profile registerUser(Registration registration) {
        ApiUser user = userManager.registerUser(registration);
        Profile profile = profileManager.createProfile(user, registration);

        mailManager.sendActivationMail(user);

        return profile;
    }

    ...
}

AuthController.java

@RestController
@RequestMapping("/api/auth")
public class AuthController {
    @Autowired
    private AuthenticationService authenticationService;

    @RequestMapping(path = "register", method = RequestMethod.POST)
    @ApiOperation(value = "Registers a user")
    public Profile register(@Valid @RequestBody Registration registration) {
        return authenticationService.registerUser(registration);
    }

    ...
}