hibernate4--OpenSessionInViewFilter

场景：hibernate3更换hibernate4后，查询对象User时抛如下异常

java.lang.ClassCastException: cn.xx.po.developer.GameLite_$$_javassist_2 cannot be cast to javassist.util.proxy.Proxy
at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.getProxy(JavassistLazyInitializer.java:148)
at org.hibernate.proxy.pojo.javassist.JavassistProxyFactory.getProxy(JavassistProxyFactory.java:73)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.createProxy(AbstractEntityTuplizer.java:758)
at org.hibernate.persister.entity.AbstractEntityPersister.createProxy(AbstractEntityPersister.java:4419)
at org.hibernate.event.internal.DefaultLoadEventListener.createProxyIfNecessary(DefaultLoadEventListener.java:334)
at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:260)
at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:152)
at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1017)
at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:944)
at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:714)
at org.hibernate.type.EntityType.resolve(EntityType.java:502)
at org.hibernate.engine.internal.TwoPhaseLoad.doInitializeEntity(TwoPhaseLoad.java:168)
at org.hibernate.engine.internal.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:137)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:1112)
at org.hibernate.loader.Loader.processResultSet(Loader.java:969)
at org.hibernate.loader.Loader.doQuery(Loader.java:917)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:348)
at org.hibernate.loader.Loader.doList(Loader.java:2550)
at org.hibernate.loader.Loader.doList(Loader.java:2536)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2366)
at org.hibernate.loader.Loader.list(Loader.java:2361)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:495)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:357)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:198)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1194)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at cn.xx.util.dbUtil.GenericDaoImpl.findTop(GenericDaoImpl.java:84)
at cn.xx.service.player.impl.UserInfoServiceImpl.findUsers(UserInfoServiceImpl.java:93)

 解决方法：

1.方法一

打开User.hbm.xml文件

<many-to-one column="GameID" name="gameID" class="cn.xx.po.developer.GameLite"/>

在对应的many-to-one中添加

lazy="false"

2. 方法二

在web.xml文件添加（注：配置在Struts2的核心Filter前面）

<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>OpenSessionInViewFilter</filter-name>
<filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
<init-param>
<param-name>sessionFactoryBeanName</param-name>
<param-value>mySessionFactory</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>OpenSessionInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>