Dan,
Thanks mate. I am yet to digest all that. I am going to get back to you and
see if it all helped.
Thank you for the time
Cheers
niv
On Fri, Dec 3, 2010 at 1:06 AM, Dan Retzlaff <dretzl...@gmail.com> wrote:
> Yes, copying entities from the entity's association collection into another
> collection will initialize the collection. If you're still getting an LIE,
> there may be another association at play (a child of Phone?).
>
> Note that I don't fully endorse the session reattachment aspect I posted.
> Not only is weaving those Hibernate classes a little tricky and a lot of
> hacky, it can cause undesirable amounts of entities to be added into the
> session. James' suggestion of putting the collection behind a Wicket model
> is more elegant. To this end, you might develop a utility which, given a
> list of Persons, returns an IModel<List<Person>> while storing only their
> IDs in the session. In the following code, BasicDao.getIdentifier() and
> BasicDao.get() simply map to Hibernate Session methods of the same name for
> entity class T.
>
> public static <T> IModel<List<T>> createListModelFromObjects(final
> BasicDao<T> dao, List<T> objectList) {
> final List<Serializable> idList = new
> ArrayList<Serializable>(objectList.size());
> for (T object : objectList) {
> idList.add(dao.getIdentifier(object));
> }
> return new LoadableDetachableModel<List<T>>(objectList) {
> @Override
> protected List<T> load() {
> return loadList(dao, idList);
> }
> };
> }
>
> private static <T> List<T> loadList(BasicDao<T> dao, List<? extends
> Serializable> idList) {
> List<T> loadList = new ArrayList<T>(idList.size());
> for (Serializable id : idList) {
> loadList.add(dao.get(id));
> }
> return loadList;
> }
>
>
> On Wed, Dec 1, 2010 at 10:26 PM, Nivedan Nadaraj <shravann...@gmail.com
> >wrote:
>
> > Hi Dan,
> >
> > Thanks for your time most appreciated.
> >
> > 1. Option 1 as you may agree, not always is a good thing to do so I would
> > drop that.
> >
> > 2. Option 2 - I have tried this in the following manner.
> >
> > As part of the look up for the Subjects via the DAO, I iterate through
> the
> > list of Person.Phones collection and assign them into a
> Collection<Phones>
> > and set it into a value Object with has a List. This is because i cannot
> > use
> > the Set in the PageableListView. In doing so, I have forced the entities
> in
> > the collection/proxy to be intialised isn't it? Looks like even with this
> > it
> > beats me.
> >
> > 3. Option 3 - I have to read up more on how I can use this code/or
> > something
> > similar, we use Spring for DI.
> >
> > Further, each time I want to view a Person detail, I do a second look up
> > when the user clicks from a list of Persons. I send issue a lookup into
> the
> > DAO to get the Person's details afresh(the exact same method I used to
> list
> > all Subjects in the first place), so this again would have refreshed the
> > Phones collection on the Person in context.
> >
> > I will try to track it down I guess it has to do with session anyway. I
> > also
> > use the CPM to hold the Model for the whole page. Not a LDM.
> >
> > Thanks again for the time
> > Cheers
> > Niv
> >
> >
> > On Thu, Dec 2, 2010 at 1:47 PM, Dan Retzlaff <dretzl...@gmail.com>
> wrote:
> >
> > > Hi Nivedan,
> > >
> > > Even though the subsequent requests have a Session open, the entities
> > with
> > > the uninitialized collections don't know about it. I'm sure if you
> track
> > it
> > > down, you can explain the "intermittent" behavior by prior access to
> the
> > > collection when the original session is open.
> > >
> > > I'd say you can either (1) configure Hibernate to load the collections
> to
> > > load unlazily, (2) manually access the collections to force them to
> > > initialize in the specific cases you're encountering LIEs, or (3)
> employ
> > > some kind of AOP hack to reinject the new session right before the
> > > collection is accessed. They're all kind of ugly, and I've never heard
> of
> > > anyone else doing the last, but it's been working well for my team.
> > >
> > > For your reference, here is the AspectJ aspect I wrote. (We use Guice
> for
> > > dependency injection.)
> > >
> > > /**
> > > * Reattaches entities whose lazy collections are about to be
> initialized
> > > * <p>
> > > * Can we keep track of all lazy relationships that get initialized,
> and
> > > * uninitialize them at the end of the request? This would prevent
> > > referenced
> > > * entities from being serialized and replicated (unless separate
> > > references
> > > * were created to them).
> > > *
> > > * @author dan
> > > */
> > > @Aspect
> > > public class ReattachAspect {
> > > private static final Logger LOG =
> Logger.getLogger(ReattachAspect.class);
> > >
> > > private Provider<Session> sessionProvider;
> > >
> > > @Before("call(public final void
> > > org.hibernate.proxy.AbstractLazyInitializer.initialize()) &&
> > > target(initializer)")
> > > public void reattachLazyInitializer(LazyInitializer initializer) {
> > > if (initializer.getSession() == null && sessionProvider != null) {
> > > if (LOG.isDebugEnabled()) {
> > > LOG.debug("reattaching session to lazy initializer for " +
> > > initializer.getEntityName());
> > > }
> > > Session session = sessionProvider.get();
> > > initializer.setSession((SessionImplementor) session);
> > > }
> > > }
> > >
> > > @Before("call(private void
> > > org.hibernate.collection.AbstractPersistentCollection"
> > > + ".throwLazyInitializationExceptionIfNotConnected()) &&
> > > target(collection)")
> > > public void reattachPersistentCollection(PersistentCollection
> collection)
> > {
> > > SessionImplementor session = ((AbstractPersistentCollection)
> > > collection).getSession();
> > > if ((session == null || !session.isOpen()) && sessionProvider != null)
> {
> > > if (LOG.isDebugEnabled()) {
> > > LOG.debug("reattaching session to collection");
> > > }
> > >
> > > session = (SessionImplementor) sessionProvider.get();
> > > CollectionPersister persister =
> > > session.getFactory().getCollectionPersister(collection.getRole());
> > >
> > > collection.setCurrentSession(session);
> > >
> >
> session.getPersistenceContext().addInitializedDetachedCollection(persister,
> > > collection);
> > > }
> > > }
> > >
> > > @Inject
> > > public void setSessionProvider(Provider<Session> sessionProvider) {
> > > this.sessionProvider = sessionProvider;
> > > }
> > > }
> > >
> > >
> > > On Wed, Dec 1, 2010 at 9:23 PM, Nivedan Nadaraj <shravann...@gmail.com
> > > >wrote:
> > >
> > > > Hi All
> > > >
> > > > I am guessing this is more of a Hibernate thing/issue but if some one
> > has
> > > > encountered this and has a explanation that I can probably use from
> the
> > > > Wicket front would be great.
> > > >
> > > > https://forum.hibernate.org/viewtopic.php?f=1&t=1008473
> > > >
> > > >
> > > > I have a LazyIntializationException when i page through some items. I
> > use
> > > > the PageableListView, the List item(s) are entities that are
> retrieved
> > > via
> > > > an association Person.phones which is a Set type.
> > > > The funny thing is, the LIException is intermittent. I am also using
> > > > OpenSessionInViewFilter. Any thoughts?
> > > >
> > > > By the way the this is the load() implemenation, I have set the Model
> > > > Object's phoneList with a list of values fetched via the
> Service->DAO.
> > I
> > > > have used this with other entities without association and it works
> > but
> > > I
> > > > guess is a different scenario(not associations)
> > > >
> > > > Model = new LoadableDetachableModel<Object>() {
> > > > @Override
> > > > protected Object load() {
> > > > return containerForm.getModelObject().getPhoneList();
> > > > }
> > > > };
> > > > }
> > > >
> > > > If someone has any thoughts would appreiciate hearing from you.
> > > >
> > > >
> > > > Cheers
> > > >
> > >
> >
>
