Hi there

I am using Spring and Hibernate for a web application I am writing. The application is for administering "Constructions". For example, buildings, bridges etc, which consist of many sub-parts. I am not sure if the problem I am seeing is Hibernate or Spring related, so please bear with me...

I have a JSP where a user can view a "Construction" object. And where the user can edit and create a new "Construction".

This was working ok, but a little slowly, so I started to investigate "lazy-loading". This sped things up remarkably, but now I have a new problem...

To enable lazy-loading to work in a web-application it appears one must maintain a Hibernate session over the entire request, to enable the JSP to completely render the "Construction" object for example. This seems to give a problem when I want to create a new "Construction".

For creating a new Construction I instantiate an "empty" Construction object which I supply to the JSP (which then renders empty fields for the user to fill in). This works fine unless I use lazy-loading (and Spring's OpenSessionInViewInterceptor). Then I get an error, which I think has something to do with Hibernate trying to synchronise my empty object with the database (?)

Does anyone have any ideas or help about this?

Thanks, Peter


Hibernate version:
2.1.6

Full stack trace of any exception that occurs:
2004-10-13 09:46:16,500 ERROR [net.sf.hibernate.impl.SessionImpl] - <Could not synchronize database state with session>
net.sf.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: dk.ciber.danbro.facility.impl.DefaultConstructionNode
at net.sf.hibernate.impl.SessionImpl.throwTransientObjectException(SessionImpl.java:2768)
at net.sf.hibernate.impl.SessionImpl.getEntityIdentifierIfNotUnsaved(SessionImpl.java:2760)
at net.sf.hibernate.type.EntityType.getIdentifier(EntityType.java:66)
at net.sf.hibernate.type.ManyToOneType.nullSafeSet(ManyToOneType.java:47)
at net.sf.hibernate.collection.AbstractCollectionPersister.writeElement(AbstractCollectionPersister.java:384)
at net.sf.hibernate.collection.Set.writeTo(Set.java:226)
at net.sf.hibernate.collection.AbstractCollectionPersister.insertRows(AbstractCollectionPersister.java:607)
at net.sf.hibernate.impl.ScheduledCollectionUpdate.execute(ScheduledCollectionUpdate.java:49)
at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2418)
at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2374)
at net.sf.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1811)
at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1568)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1533)
at net.sf.hibernate.impl.QueryImpl.list(QueryImpl.java:39)
at org.springframework.orm.hibernate.HibernateTemplate$21.doInHibernate(HibernateTemplate.java:402)
at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:176)
at org.springframework.orm.hibernate.HibernateTemplate.executeFind(HibernateTemplate.java:196)
at org.springframework.orm.hibernate.HibernateTemplate.find(HibernateTemplate.java:399)
at dk.ciber.danbro.common.impl.HibernateDao.query(HibernateDao.java:112)
at dk.ciber.danbro.catalogue.impl.DefaultCatalogueManager.getCatalogueNodes(DefaultCatalogueManager.java:51)
at dk.ciber.danbro.facility.web.SimpleFacilityFormController.generateDataLists(SimpleFacilityFormController.java:171)
at dk.ciber.danbro.facility.web.SimpleFacilityFormController.referenceData(SimpleFacilityFormController.java:119)
at org.springframework.web.servlet.mvc.SimpleFormController.referenceData(SimpleFormController.java:164)
at org.springframework.web.servlet.mvc.AbstractFormController.showForm(AbstractFormController.java:365)
at org.springframework.web.servlet.mvc.AbstractFormController.showForm(AbstractFormController.java:342)
at org.springframework.web.servlet.mvc.SimpleFormController.showForm(SimpleFormController.java:190)
at org.springframework.web.servlet.mvc.AbstractFormController.showNewForm(AbstractFormController.java:284)
at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:240)
at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:121)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:45)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:485)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:322)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:284)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:204)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:257)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:245)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:199)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:184)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:164)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:149)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:156)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:151)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:972)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:206)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:833)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:732)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:619)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:688)
at java.lang.Thread.run(Thread.java:534)

Have you put 'cascade="all"' in your 'collection' (set, list, map...) in your .hbm file?