在AbstractEntityPersister (Hibernate)中将StatelessSession强制转换为会话

Question

我正在试着在StatelessSession上做一个简单的节省。有没有人能发现我做错了什么，最终进入了Hibernate方法，该方法试图将StatelessSession转换为会话。如果有任何反馈，我将不胜感激。

我的示例代码：StatelessSession statelessSession = getSessionFactory().openStatelessSession(); Transaction tx = statelessSession.beginTransaction(); Object ret = null; try { ret = statelessSession.insert(obj); tx.commit(); statelessSession.close();

     `} catch (Throwable t) {             System.out.println("exception: " + t.getMessage());             tx.rollback();         }          return (T) ret;`

异常发生在.insert(obj)调用上。跟踪代码后，我进入了AbstractEntityPersister类，它尝试在此方法中将StatelessSession转换为Session：

    private void preInsertInMemoryValueGeneration(Object[] fields, Object object, SessionImplementor session) {
    if ( getEntityMetamodel().hasPreInsertGeneratedValues() ) {
        final InMemoryValueGenerationStrategy[] strategies = getEntityMetamodel().getInMemoryValueGenerationStrategies();
        for ( int i = 0; i < strategies.length; i++ ) {

            if ( strategies[i] != null && strategies[i].getGenerationTiming().includesInsert() ) {
                fields[i] = strategies[i].getValueGenerator().generateValue( (Session) session, object );  // <-- bad cast here
                setPropertyValue( object, i, fields[i] );
            }
        }
    }
}

下面是堆栈跟踪：

java.lang.ClassCastException: org.hibernate.internal.StatelessSessionImpl cannot be cast to org.hibernate.Session
at org.hibernate.persister.entity.AbstractEntityPersister.preInsertInMemoryValueGeneration(AbstractEntityPersister.java:3591)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3568)
at org.hibernate.internal.StatelessSessionImpl.insert(StatelessSessionImpl.java:144)
at org.hibernate.internal.StatelessSessionImpl.insert(StatelessSessionImpl.java:123)
at com.mycompany.somepackage.dao.impl.CommonDAOImpl.persist2(CommonDAOImpl.java:242)
at com.mycompany.somepackage.publisher.ScJournalPublisher.publish(ScJournalPublisher.java:37)
at com.mycompany.somepackage.annotation.callback.CallbackInvoker.invokePublisherCallback(CallbackInvoker.java:92)
at com.mycompany.somepackage.event.listener.DaPostInsertUpdateEventListener.onPostInsert(DaPostInsertUpdateEventListener.java:51)
at org.hibernate.action.internal.EntityInsertAction.postInsert(EntityInsertAction.java:177)
at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:145)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:465)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:351)
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:350)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:56)
at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1258)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:425)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:177)
at org.springframework.orm.hibernate4.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:584)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:757)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:726)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:521)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)

Answer 1

已经存在为此打开的出库请求！这在Hibernate 5.2.2中应该是可用的

https://hibernate.atlassian.net/browse/HHH-11048

getEntityMetamodel().hasPreInsertGeneratedValues()返回true，因为在插入之前，您必须拥有由hibernate生成的内容！

例如:时间戳或自动生成的ids等。

Answer 2

此问题在Hibernate最新版本(5.4.09)中仍然存在

实际问题出在entity类中，如果entity类有一些自动生成的属性，比如@CreationTimestamp，hibernate StatelessSession插入/更新函数会抛出这个错误"java.lang.ClassCastException: org.hibernate.internal.StatelessSessionImpl cannot be cast to org.hibernate.Session“

例如：

@CreationTimestamp私有日期createdDate；

Solution通过手动设置这些属性。