Spring boot @Transactional doesn't work

Question

I had add @Transactional on the method in service layer.

@Transactional(readOnly = false)
public void add(UserFollow uf){
    UserFollow db_uf = userFollowRepository.findByUserIdAndFollowUserId(uf.getUserId(), uf.getFollowUserId());
    if(db_uf == null) { 
        userFollowRepository.save(uf);      
        userCountService.followInc(uf.getFollowUserId(), true);
        userCountService.fansInc(uf.getUserId(), true);

        throw new RuntimeException();// throw an Exception
    }
}

userFollowRepository.save(uf); still save seccessful，doesn't rollback...

i enable transaction manager on the Application.

@Configuration  
@ComponentScan 
@EnableAutoConfiguration  
@EnableJpaRepositories
@EnableTransactionManagement
public class Application {  

    @Bean
    public AppConfig appConfig() {
       return new AppConfig();
    }

    public static void main(String[] args) {  
       SpringApplication.run(Application.class);  
    }  
}  

i move @Transactional to Control layer, it works, the code:

@Transactional
@RequestMapping(value="following", method=RequestMethod.POST)
public MyResponse follow(@RequestBody Map<String, Object> allRequestParams){
    MyResponse response = new MyResponse();

    Integer _userId = (Integer)allRequestParams.get("user_id");
    Integer _followUserId = (Integer)allRequestParams.get("follow_user_id");



    userFollowService.add(_userId, _followUserId); //this will throw an exception, then rollback


    return response;
}

can anyone tell me reason, thanks！

Answer 1

According to http://spring.io/guides/gs/managing-transactions/

@EnableTransactionManagement activates Spring’s seamless transaction features, which makes @Transactional function

so it started to work after you had added @EnableTransactionManagement