mysql - QueryDslJpaRepository.findAll 批量更新从更新 [0] 返回了意外的行数；实际行数 : 0; expected: 1

Question

我在生产环境中时常遇到这个异常，一直无法在本地重现。其他人也有这个问题，但更新或删除时都会出现。

我有一个监听器类映射到 prePersist() 上的 Tag 类，确保用户没有保存超过 x 个标签。

标签类是:

    @Entity
    @EntityListeners({ TagListener.class })
    public class Tag extends AbstractEntity {

    ...
    }

TagService 类保存标签对象。

@Service
public class TagService extends AbstractService<Tag> {

public Tag saveTagForUser(AbstractEntity entity, User user) {
...
return save(tag);       

}

The TagListener listens when tag objects are saved and deletes some of them if that is necessary.

@Component
public class TagListener {

    @Autowired
    private TagService tagService;

    /**
     * Autowires this component's bean injections.
     */
    private void autowire() {
        if (tagService == null) {
            ApplicationContextProvider.getApplicationContext().getAutowireCapableBeanFactory().autowireBean(this);
        }
    }

    @PrePersist
    public void prePersist(Tag tag) {
        autowire();
        if (tagService.listUserTags(tag.getUser()).size() > Constants.Tags.maxPerUser) {
            tagService.deleteAllUserTagsNotInTopN(tag.getUser(), Constants.Tag.maxPerUser);
        }
    }
}

Note that the exception is thrown on listUserTags, and NOT on deleteAllUserTagsNotInTopN

**javax.persistence.OptimisticLockException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1**
    at **org.hibernate.jpa.spi.AbstractEntityManagerImpl.wrapStaleStateException(AbstractEntityManagerImpl.java:1800)**
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1705)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1677)
    at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:458)
    at **com.mysema.query.jpa.impl.AbstractJPAQuery.getResultList(AbstractJPAQuery.java:197)**
    at com.mysema.query.jpa.impl.AbstractJPAQuery.list(AbstractJPAQuery.java:249)
    at org.springframework.data.jpa.repository.support.QueryDslJpaRepository.findAll(QueryDslJpaRepository.java:101)
    at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:42)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:414)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:399)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:371)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    **at com.sun.proxy.$Proxy114.findAll(Unknown Source)
    at ro.app.service.tag.TagService.listUserTags(TagService.java:823)
    at ro.app.listener.TagListener.prePersist(TagListener.java:47)**
    at sun.reflect.GeneratedMethodAccessor174.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:42)
    at org.hibernate.jpa.event.internal.jpa.ListenerCallback.performCallback(ListenerCallback.java:49)
    at org.hibernate.jpa.event.internal.jpa.CallbackRegistryImpl.callback(CallbackRegistryImpl.java:112)
    at org.hibernate.jpa.event.internal.jpa.CallbackRegistryImpl.preCreate(CallbackRegistryImpl.java:57)
    at org.hibernate.jpa.event.internal.core.JpaPersistEventListener.saveWithGeneratedId(JpaPersistEventListener.java:83)
    at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:206)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:149)
    at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:75)
    at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:811)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:784)
    at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:789)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:1181)
    at sun.reflect.GeneratedMethodAccessor173.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:42)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:291)
    at com.sun.proxy.$Proxy97.persist(Unknown Source)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:431)
    at sun.reflect.GeneratedMethodAccessor94.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:42)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:414)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:399)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:371)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy114.save(Unknown Source)
    at ro.app.service.AbstractService.save(AbstractService.java:530)
    **at ro.app.service.TagService.saveTagForUser(TagService.java:351)**

保存标签对象是在事务中完成的。任何线索可能是什么问题？谢谢!

Answer 1

显然，问题是因为删除标签(在 deleteAllUserTagsNotInTopN() 方法中完成)，尽管它在堆栈跟踪中不可见。在 TagRepository 中，我用 deleteInBatch 方法替换了 delete 方法:

public interface TagRepository extends JpaRepository<Tag,Long> {

     void deleteInBatch(Iterable<Notification> notifications);
}