如果出现org.hibernate.LazyInitializationException异常，session was closed，那是因为你使用了JPA或者hibernate的延时加载方法，并在访问对象的时候，session已经关闭。
一：hibernate 解决
在web.xml中加
<filter>
<filter-name>HibernateFilter</filter-name>
<filter-class>org.springframework.orm.hibernate3.OpenSessionInviewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>HibernateFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping> -->
二：Jpa解决
在web.xml中加
<filter>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>SpringOpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
