SessionFactory的抛出异常

Question

我想有以下行从JPA的EntityManager的获得Hibernate的SessionFactory的：

@PersistenceContext 
EntityManager manager; 

public SessionFactory getSessionFactory(){ 
    sessionFactory = manager.unwrap(SessionFactory.class); 
} 

但引发此异常：

org.springframework.orm.jpa.JpaSystemException: Hibernate cannot unwrap interface org.hibernate.SessionFactory; nested exception is javax.persistence.PersistenceException: Hibernate cannot unwrap interface org.hibernate.SessionFactory 
at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:418) 
... 

Caused by: javax.persistence.PersistenceException: Hibernate cannot unwrap interface org.hibernate.SessionFactory 
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.unwrap(AbstractEntityManagerImpl.java:1489) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
... 

可能是什么原因为了这？

在此先感谢

Answer 1

不能使用unwrap获取会话工厂，你可以用它去获取会话。
从会议，你可以得到工厂，如果你需要：

public SessionFactory getSessionFactory(){ 
    Session session = manager.unwrap(Session.class); 
    sessionFactory = session.getSessionFactory(); 
}