Spring boot + Hibernate + JPA没有事务性的EntityManager可用

Question

我使用Spring引导1.2.3.RELEASE版本与JPA over hibernate.我遇到以下异常

org.springframework.dao.InvalidDataAccessApiUsageException: No transactional EntityManager available; nested exception is javax.persistence.TransactionRequiredException: No transactional EntityManager available
at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:410) ~[EntityManagerFactoryUtils.class:4.1.6.RELEASE]
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:223) ~[HibernateJpaDialect.class:4.1.6.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:417) ~[AbstractEntityManagerFactoryBean.class:4.1.6.RELEASE]
at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) ~[ChainedPersistenceExceptionTranslator.class:4.1.6.RELEASE]
at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[DataAccessUtils.class:4.1.6.RELEASE]
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) ~[PersistenceExceptionTranslationInterceptor.class:4.1.6.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [ReflectiveMethodInvocation.class:4.1.6.RELEASE]
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122) ~[CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.class:na]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [ReflectiveMethodInvocation.class:4.1.6.RELEASE]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) [ExposeInvocationInterceptor.class:4.1.6.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [ReflectiveMethodInvocation.class:4.1.6.RELEASE]
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) [JdkDynamicAopProxy.class:4.1.6.RELEASE]
at com.sun.proxy.$Proxy110.deleteByCustomerId(Unknown Source) ~[na:na]

Caused by: javax.persistence.TransactionRequiredException: No transactional EntityManager available
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:275) ~[SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.class:4.1.6.RELEASE]
at com.sun.proxy.$Proxy102.remove(Unknown Source) ~[na:na]
at org.springframework.data.jpa.repository.query.JpaQueryExecution$DeleteExecution.doExecute(JpaQueryExecution.java:270) ~[JpaQueryExecution$DeleteExecution.class:na]
at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:74) ~[JpaQueryExecution.class:na]
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:97) ~[AbstractJpaQuery.class:na]
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:88) ~[AbstractJpaQuery.class:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:395) ~[RepositoryFactorySupport$QueryExecutorMethodInterceptor.class:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:373) ~[RepositoryFactorySupport$QueryExecutorMethodInterceptor.class:na]

以下是我的程序结构
配置类

@Configuration
@ComponentScan
@EnableAutoConfiguration
@EnableTransactionManagement
public class WSApplication {
    public static void main(final String[] args) {
        SpringApplication.run(WSApplication.class, args);
    }
}

@Entity
@Table(Orders)
public class Order {
    @id
    @GeneratedValue
    private long id;

    @Column(name = "customerId")
    private Long customerId;

    // getter & setter methods
    // equals & hashCode methods
}

public interface OrderRepository extends JpaRepository<Order, Long> {

    List<Order> findByCustomerId(Long customerId);

    // 4- @Transactional works fine
    void deleteByCustomerId(Long cusotmerId);

}

public class OrderService {

    @Autowired
    private OrderRepository repo;

    // 3- @Transactional works fine
    public void deleteOrder(long customerId){
        //1- throws exception
        repo.deleteByCustomerId(customerId); 

        //2- following works fine
        //repo.delete(repo.findByCustomerId(customerId).get(0));
    }

}

在上面的服务类代码中,任何人都可以请指导我为什么2个工作和1个抛出异常.

谢谢

Answer 1

首先,我引用Spring-Data JPA文档来证明为什么该delete方法适用于您的情况(我的意思是选项2).

默认情况下,存储库实例上的CRUD方法是事务性的.对于读取操作,事务配置readOnly标志设置为true,所有其他标志配置为plain,@Transactional以便应用默认事务配置.有关详细信息,请参阅CrudRepository的JavaDoc

该delete方法实际上是一种方法CrudRepository.您的存储库扩展JpaRepository了扩展CrudRespository,因此它属于CrudRepository接口,根据上面的引用是事务性的.

如果您阅读" 事务查询方法 "一节,您将看到与选项4相同的内容,您将了解如何为存储库的所有方法应用自定义事务行为.此外,文档的示例61显示了与选项3相同的方案.

现在请记住,您没有使用JDBC逻辑,在这种情况下,数据库会处理事务,但在基于ORM的框架内.ORM框架需要事务才能触发对象缓存和数据库之间的同步.因此,您必须了解并为执行ORM逻辑的方法提供事务上下文deleteByCustomerId.

默认情况下@Transactional(我的意思是没有任何参数)将传播模式设置为REQUIRED和readOnly标志为false.当您调用在其中注释的方法时,如果不存在,则会初始化事务.这就是为什么@LucasSaldanha 的解决方法(与使用Facade定义多个存储库调用的事务的示例相同)和选项4的工作原理.其他明智的做法是,如果没有交易,您将陷入选项1的抛出异常中.