Spring中非事务方法调用事务方法仍启事务？IntelliJ警告存疑

在Spring Boot 3.2.2环境下，我遇到一个事务相关的疑问：PersonService类的非事务方法createPerson调用了标注@Transactional的createPersonTransactional方法。IntelliJ IDEA高亮该调用，提示这是事务自调用，运行时不会触发事务，但控制器调用createPerson方法后，日志却显示事务已创建。我原本认为这类内部方法调用会直接执行原方法而非Spring生成的事务代理方法，因此疑惑IntelliJ的警告是否错误？

代码示例 #

@Service
class PersonService(val personRepository: PersonRepository) {

    fun createPerson(personRequest: PersonRequest): Person {
        return createPersonTransactional(personRequest)
    }

    @Transactional
    fun createPersonTransactional(personRequest: PersonRequest): Person {
        val person = Person(name = personRequest.name)
        personRepository.save(person)
        return person
    }
}

interface PersonRepository : JpaRepository<Person, String>


@RestController
class PersonController(
    private val personService: PersonService
) {
    @PostMapping("/person", produces = [MediaType.APPLICATION_XML_VALUE])
    fun createPerson(@RequestBody personRequest: PersonRequest): Person {
        return personService.createPerson(personRequest)
    }

}

运行日志 #

2024-02-09T09:38:32.084Z DEBUG 5102 --- [nio-8081-exec-3] o.s.web.servlet.DispatcherServlet        : POST "/person", parameters={}
2024-02-09T09:38:32.084Z DEBUG 5102 --- [nio-8081-exec-3] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped to com.example.rosbug.PersonController#createPerson(PersonRequest)
2024-02-09T09:38:32.084Z DEBUG 5102 --- [nio-8081-exec-3] o.j.s.OpenEntityManagerInViewInterceptor : Opening JPA EntityManager in OpenEntityManagerInViewInterceptor
2024-02-09T09:38:32.152Z DEBUG 5102 --- [nio-8081-exec-3] m.m.a.RequestResponseBodyMethodProcessor : Read "application/json;charset=UTF-8" to [PersonRequest(name=bert)]
2024-02-09T09:38:32.178Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Found thread-bound EntityManager [SessionImpl(1455667122<open>)] for JPA transaction
2024-02-09T09:38:32.178Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Creating new transaction with name [org.springframework.data.jpa.repository.support.SimpleJpaRepository.save]: PROPAGATION_REQUIRED,ISOLATION_DEFAULT
2024-02-09T09:38:32.182Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Exposing JPA transaction as JDBC [org.springframework.orm.jpa.vendor.HibernateJpaDialect$HibernateConnectionHandle@65c57510]
2024-02-09T09:38:32.283Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Initiating transaction commit
2024-02-09T09:38:32.283Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Committing JPA transaction on EntityManager [SessionImpl(1455667122<open>)]
2024-02-09T09:38:32.305Z DEBUG 5102 --- [nio-8081-exec-3] o.s.orm.jpa.JpaTransactionManager        : Not closing pre-bound JPA EntityManager after transaction
2024-02-09T09:38:32.308Z DEBUG 5102 --- [nio-8081-exec-3] m.m.a.RequestResponseBodyMethodProcessor : Using 'application/xml', given [*/*] and supported [application/xml]
2024-02-09T09:38:32.320Z DEBUG 5102 --- [nio-8081-exec-3] m.m.a.RequestResponseBodyMethodProcessor : Writing [com.example.rosbug.Person@3b4eb178]
2024-02-09T09:38:32.340Z DEBUG 5102 --- [nio-8081-exec-3] o.j.s.OpenEntityManagerInViewInterceptor : Closing JPA EntityManager in OpenEntityManagerInViewInterceptor
2024-02-09T09:38:32.341Z DEBUG 5102 --- [nio-8081-exec-3] o.s.web.servlet.DispatcherServlet        : Completed 200 OK

解答 #

IntelliJ的警告没有错误，你看到的事务并非来自createPersonTransactional方法上的@Transactional注解，而是来自Spring Data JPA的save方法本身。

关键分析点： #

• Spring事务代理机制：内部方法调用（同一个类中方法互相调用）确实不会触发Spring的事务代理增强，所以你自己标注在createPersonTransactional上的@Transactional并未生效。
• 日志中的事务来源：日志里明确显示事务名称是org.springframework.data.jpa.repository.support.SimpleJpaRepository.save，说明这个事务是由JpaRepository的默认实现类SimpleJpaRepository的save方法触发的——Spring Data JPA的save方法自带@Transactional注解，默认会开启事务。
• 验证方式：可以在createPersonTransactional的personRepository.save(person)之后手动抛出一个异常，观察数据是否回滚。如果是createPersonTransactional的事务生效，数据会被回滚；但实际情况是数据不会回滚，因为事务是save方法的，save执行完成后事务已经提交，后续异常无法触发回滚。

简单来说：IntelliJ警告的是你自己写的@Transactional不会生效，而日志里的事务是Spring Data JPA自带的，两者并不冲突。

内容的提问来源于stack exchange，提问作者PaulNUK