org.hibernate.LazyInitializationException: failed to lazily initialize a collection

[cf1337]

AGAIN - web is full of these, but none covers my problem.

How comes?
I have several datastructures like Container (Class with a list) and Content (Contentclass of the list with some values)

This is the expected behaviour when compiling from xsd schemata - i think

So i want these xml-related objects to be persisted in my database.
Currently this is a HYPERSONIC_IN_MEMORY

All classes are Annotated with their @Xml and @JPA-Annotations.

Additionally i used spring-ROO (latest version from git) to scaffold my applcation with Google Web Toolkit
Plus a Importer-Widget to get Data into the database.

Now - as soon as i imported a Container and its Contents into the GWT-Application, i cannot access "Containers" anymore

[ERROR] 11.05.2011 22:51:30 com.google.gwt.requestfactory.server.RequestFactoryServlet doPost
[ERROR] SCHWERWIEGEND: Unexpected error
[ERROR] org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: de.test.server.domain.Container.ct, no session or session was closed
[ERROR] 	at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383)
[ERROR] 	at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375)
[ERROR] 	at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:368)
[ERROR] 	at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:111)
[ERROR] 	at org.hibernate.collection.PersistentBag.iterator(PersistentBag.java:272)
[ERROR] 	at com.google.gwt.requestfactory.server.Resolver.resolveClientValue(Resolver.java:441)
[ERROR] 	at com.google.gwt.requestfactory.server.Resolver.access$200(Resolver.java:49)
[ERROR] 	at com.google.gwt.requestfactory.server.Resolver$1.visitReferenceProperty(Resolver.java:359)
[ERROR] 	at com.google.gwt.autobean.shared.AutoBeanVisitor.visitCollectionProperty(AutoBeanVisitor.java:165)
[ERROR] 	at com.google.gwt.autobean.server.ProxyAutoBean.traverseProperties(ProxyAutoBean.java:251)
[ERROR] 	at com.google.gwt.autobean.shared.impl.AbstractAutoBean.traverse(AbstractAutoBean.java:153)
[ERROR] 	at com.google.gwt.autobean.shared.impl.AbstractAutoBean.accept(AbstractAutoBean.java:112)

Weird thing is, this appears as soon, as i import data from xml. The code snippet:

			    byte[] fileContents = uploadItem.get();
				ApplicationContext ctx = new ClassPathXmlApplicationContext("META-INF/spring/applicationContext.xml");
			    MyMarshaller as = ctx.getBean("myMarshaller", MyMarshaller.class);
			    Container mb = as.importContainer(new String(fileContents));
			    System.out.println(mb.toString());
			    mb.persist();

This persists (at least i think so) also the generated Content-Objects.
I can also access the Content-Objects from the GWT-App.

I broke the project down into a minimal example.
Please try my code and give feedback. Could this a scffolding project with roo?
Just unzip the file into a fresh folder and run

mvn gwt:run

Import the test.xml file

[cf1337]

exactly this line:

				ApplicationContext ctx = new ClassPathXmlApplicationContext("META-INF/spring/applicationContext.xml");

generates a new Context and messes up the Application.

One should use WebApplicationContext generating an springContext from HttpServlet's getContext() method