DWR/OpenSessionInView “Session is Closed!” in Java and Hibernate

Question

They say that a closed session in hibernate and webapp with ajax is a common problem with java and spring so I have to set the OpenSessionInViewInFilter in the web.xml like this

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>    
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/applicationContext.xml
    </param-value>
</context-param>
<filter>
    <filter-name>springFilter</filter-name>
    <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>springFilter</filter-name>
    <url-pattern>/dwr/*</url-pattern>
</filter-mapping>

But even with that, I get the "Session is Closed" hibernate exception when I try to use Hibernate Criteria api, so I tried another spring way using OpenSessioninViewInterceptor

<bean id="urlMapping"
    class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    <property name="alwaysUseFullPath" value="false"/>
     <property name="mappings">
            <props>
                <prop key="*">dwrController</prop>
            </props>
    </property>
    <property name="interceptors">

and the interceptor

<bean id="openSessionInViewInterceptor"class="org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor">

Same "Session is closed" problem. Please help me here. I am new in Java so your help is very much appreciated.

I am currently running inside maven's jetty plugin, version 6.1.10.

Answer 1

Make sure you don't pass the data across different threads. This is especially easy if you use lazy loading (check your hibernate mapping defaults).

Say if an entity Y is lazy loaded and is referenced from entity X (via Hibernate) and you pass X from one thread to another and in this another thread you do x.getY(), you are in trouble.

Answer 2

Found it. I need to declare @Transactional in my service class.