This exception appears about once/hour, really annoying me.
And I am not sure if it will get much more frequestly with the improve of concurrency.

My analysis:
I open session for every thread, so the "no session" is impossible.
It seems that the session is closed by other thread before the owning thread make everything done.
But, I manipulate session with ThreadLocal and close session in filter,
so, the session shouldn't be closed by other thread!!!!


Hibernate version:
Hibernate 2.1.8

Mapping documents:

Code between sessionFactory.openSession() and session.close():

filter:

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
Log log = LogFactory.getLog(this.getClass());
try {
chain.doFilter(request, response);
} catch (Exception e) {
log.error(e);
} finally {
try {
HibernateUtil.closeSession();
} catch (HibernateException e1) {
log.error(e1);
}
}
}

helper class:

public class HibernateUtil {

private static SessionFactory sessionFactory;

static {
try {
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
System.out.println("Initial SessionFactory creation failed.");
throw new ExceptionInInitializerError(ex);
}
}

public static final ThreadLocal session = new ThreadLocal();

public static Session currentSession() throws HibernateException {
Session s = (Session) session.get();
if (s == null) {
s = sessionFactory.openSession();
session.set(s);
}
return s;
}

public static void closeSession() throws HibernateException {
Session s = (Session) session.get();
session.set(null);
if (s != null) {
s.close();
}
}
}

The BaseAction, all my other actions extend it:

public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) {
HttpSession session = request.getSession(true);
Transaction tx = null;
Log log = LogFactory.getLog(this.getClass());
try {
Session ss = HibernateUtil.currentSession();
tx = ss.beginTransaction();

// process code here
// process code here
// process code here

tx.commit();
return mapping.findForward("suc");
} catch (HibernateException e) {
if (tx != null) {
try {
tx.rollback();
} catch (HibernateException e1) {
e1.printStackTrace();
}
}
e.printStackTrace();
return mapping.findForward("fail");
} catch (SQLException e) {
if (tx != null) {
try {
tx.rollback();
} catch (HibernateException e1) {
e1.printStackTrace();
}
}
e.printStackTrace();
return mapping.findForward("fail");
} catch (IOException e) {
if (tx != null) {
try {
tx.rollback();
} catch (HibernateException e1) {
e1.printStackTrace();
}
}
e.printStackTrace();
return mapping.findForward("fail");
} catch (Exception e) {
if (tx != null) {
try {
tx.rollback();
} catch (HibernateException e1) {
e1.printStackTrace();
}
}
e.printStackTrace();
return mapping.findForward("fail");
}
}


Full stack trace of any exception that occurs:
ApplicationDispatcher[] Servlet.service() for servlet jsp threw exception
net.sf.hibernate.LazyInitializationException: Failed to lazily initialize a collection - no session or session was closed
at net.sf.hibernate.collection.PersistentCollection.initialize(PersistentCollection.java:209)
at net.sf.hibernate.collection.PersistentCollection.read(PersistentCollection.java:71)
at net.sf.hibernate.collection.Set.iterator(Set.java:130)
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.toForEachIterator(ForEachSupport.java:360)
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.supportedTypeForEachIterator(ForEachSupport.java:238)
at org.apache.taglibs.standard.tag.common.core.ForEachSupport.prepare(ForEachSupport.java:172)
at javax.servlet.jsp.jstl.core.LoopTagSupport.doStartTag(LoopTagSupport.java:262)
at org.apache.jsp.pages.viewUser_jsp._jspx_meth_c_forEach_11(viewUser_jsp.java:4650)
at org.apache.jsp.pages.viewUser_jsp._jspx_meth_c_if_9(viewUser_jsp.java:4614)
at org.apache.jsp.pages.viewUser_jsp._jspService(viewUser_jsp.java:442)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:704)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:474)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:409)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at com.dodoyo.filter.DodoyoFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:186)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:300)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:374)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:743)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:675)
at org.apache.jk.common.SocketConnection.runIt(ChannelSocket.java:866)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Thread.java:534)

Name and version of the database you are using:
PostgreSQL 7.4.3
The generated SQL (show_sql=true):

Debug level Hibernate log excerpt:

Hi,

I experienced this same problem. You have to realize that, contrary to what you might expect, your Filter gets hit every time for every JSP include or tile. So, using a servlet filter does not guarantee a single Hibernate session across the request.

So, your session is closed and opened multiple times. In case of uninitialized elements in objects you use across these multiple sessions you will run into unitialized exceptions and the like.

I see you're using Struts. The solution is to extend your request processor and configure it to be called from your struts config. Open and close the hibernate session inside the process method of your extended request processor and you will have a guaranteed single hibernate session for the duration of the request.

something like
****extended requestprocessor******

public void process(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
try{
HibernateUtil.openSession();
catch(HibernateException he){
logger.error(he);
throw new ServletException(he);
}
//reattach any httpsession objects that may contain uninitialized collections
try{
super.process(request,response);
catch(Exception e){
logger.error(e);
throw new ServletException(e);
}finally{
try{
HibernateUtil.closeSession();
}catch(HibernateException he){
logger.warn(he);
}
}


Cheers,

Marc

Thanks a lot :)
I will try it and give the result in several days

I tried this approach.
It seems that it doesn't work.

What kind of problems do you experience?

Marc

I disabled the filter,
extended the RequestProcessor.
But the exception appears as before:(

I cannot help you without more specific info. Did you reference your extended request processor from the struts-config.xml?


<controller>
<set-property property="processorClass" value="your.package.CustomRequestProcessor" />
</controller>


Marc

yes, so I did.
otherwise, there will be many connections leave unclosed.

Any way, Thank you very much.