在做单元测试的始终是报如下异常：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [beans.xml]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: No PersistenceProvider
specified in EntityManagerFactory configuration, and chosen PersistenceUnitInfo does not specify a provider class name either
后来才发现是忘了在persisitence.xml文件中添加
<provider>org.hibernate.ejb.HibernatePersistence</provider>