场景：hibernate3更换hibernate4后，查询对象时抛如下异常
找不到关联的类
解决方法：
1.方法一
打开hbm.xml文件
<many-one>
改为
lazy="false"
2. 方法二
在web.xml文件添加
< filter >
< filter-name > HibernateOpenSession</ filter-name >
< filter-class > org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</ filter-class >
</ filter >
< filter-mapping >
< filter-name > HibernateOpenSession</ filter-name >
< url-pattern > /*</ url-pattern >
</ filter-mapping >
注：OpenSessionInViewFilter类中有个属性叫 sessionFactoryBeanName默认值为sessionFactory，如果Spring中配置的SessionFactory不叫这个名字时，需要指定SessionFactory的名字，否则会引起org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named ‘sessionFactory‘ is defined异常。
< filter >
< filter-name > HibernateOpenSession</ filter-name >
< filter-class > org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</ filter-class >
< init-param >
< param-name > sessionFactoryBeanName</ param-name >
< param-value > mySessionFactory</ param-value >
</ init-param >
</ filter >
< filter-mapping >
< filter-name > HibernateOpenSession</ filter-name >
< url-pattern > /*</ url-pattern >
</ filter-mapping >
原文：http://www.cnblogs.com/tongxinyuan/p/4432979.html