1

我正在尝试在我的服务类的 init 方法中从 DB 加载一些数据,但是当我调用“getResultList()”方法时,它会引发异常“会话已关闭”。

我的 applicationContext.xml

<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />    
<bean id="testService" class="com.impl.TestServiceImpl" init-method="init" />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />

我的服务等级:

public Class TestServiceImpl implements TestService {
private EntityManager entityManager;

@PersistenceContext
public void setEntityManager(EntityManager entityManager) {
   this.entityManager = entityManager;
}   

public void init() {
    Query query = entityManager.createQuery("from myTable");
    query.getResultList();  // this causes error...
}
}

这是错误消息:

SEVERE: Exception sending context initialized event to listener instance of class 
org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 
'testService' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: 
Invocation of init method failed; nested exception is
javax.persistence.PersistenceException: org.hibernate.SessionException: Session is 
closed!
Caused by: javax.persistence.PersistenceException: org.hibernate.SessionException: 
Session is closed!
at 
org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:630)

那么我在这里做错了什么?我该如何解决这个问题?谢谢。

4

1 回答 1

2

首先,您TestServiceImpl没有用 注释@Transactional,但即使是,它也不起作用,请参阅:Transactional init-method and SPR-2740 - 这解释了这是设计使然。

你可以做的是init()只使用方法来调用其他一些bean的业务方法,它被标记为@Transactional

private TestDao testDao;

public void init() {
  testDao.findAll();
}

TestDaobean 中:

private EntityManager entityManager;

@Transactional
public findAll() {
  Query query = entityManager.createQuery("from myTable");
  return query.getResultList();
}
于 2011-10-16T20:46:35.810 回答