initialization process leads to Collection detected as dirty

dboucquey · **Joined:** Fri Mar 05, 2004 11:02 am **Posts:** 3

It seems that Hibernate Collection initialization process causes the collection to be identified as dirty by the dirty-checking mechanism !!!

Hibernate then generates “update” (i.e. identifies them as dirty) on collections that were only touched by Hibenate.

I do not understand what happens: In my understanding, an object should never be considered as dirty after Hibernate-only manipulation.

Here is the object model :

Merchant (table: MERCHANT) has a property additionalData:Map (table: MERCHANTBUSINESSDATA) (1 Merchant – n BusinessData)

Merchant has a property merchantContact:Contact (many-to-one) (table: CONTACT) – the same contact can manage several merchants

Contact has a property postalAddresses:Map<Address>objects identified by a key (String) (table: ADDRESS) – a Contact can have several addresses

I am using Hibernate via Spring HibernateDaoSupport

My Dao has the following method (I want to fetch all collections eagerly):

Code:

      public Merchant findMerchantByMerchantId(final String merchantId) {
            Merchant merchant = (Merchant) getHibernateTemplate().execute(
                        new HibernateCallback() {
                              public Object doInHibernate(Session session) throws HibernateException {
                                   Criteria criteria = session.createCriteria(Merchant.class);
                                   criteria.add(Expression.eq("merchantId", merchantId));
                                   criteria.setFetchMode("additionalData", FetchMode.JOIN);
                                   criteria.setFetchMode("merchantContact.postalAddresses", FetchMode.JOIN);
                                   Merchant mb = (Merchant) criteria.uniqueResult();
                                   return mb;
                              }
                        });
            return merchant;
      }

Spring AOP surrounds the retrieve by criteria in a transaction.

in the log I get
-- SELECT part

Code:

...
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.engine.StatefulPersistenceContext,790,Worker-0) []  initializing non-lazy collections
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.jdbc.ConnectionManager,302,Worker-0) []  transaction completed on session with on_close connection release mode; be sure to close the session to release JDBC resources!

-- end of select
-- session is closed, so flushing takes place -> OK

Code:

...
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.event.def.AbstractFlushingEventListener,111,Worker-0) []  processing flush-time cascades
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.event.def.AbstractFlushingEventListener,154,Worker-0) []  dirty checking collections

-- It finds that all my collections are dirty -> WHY ?

Code:

...
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.engine.Collections,176,Worker-0) []  Collection found: [be.eft.cbkv3.data.schema.customer.Contact.postalAddresses#3000637608], was: [be.eft.cbkv3.data.schema.customer.Contact.postalAddresses#3000637608] (initialized)
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.engine.Collections,176,Worker-0) []  Collection found: [be.eft.cbkv3.data.schema.customer.Merchant.additionalData#3000637607], was: [be.eft.cbkv3.data.schema.customer.Merchant.additionalData#3000637607] (initialized)

-- Therefore it generates 4 updates, though I just want to select my Merchant

Code:

...
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.event.def.AbstractFlushingEventListener,85,Worker-0) []  Flushed: 0 insertions, 3 updates, 0 deletions to 3 objects
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.event.def.AbstractFlushingEventListener,91,Worker-0) []  Flushed: 0 (re)creations, 0 updates, 0 removals to 2 collections

-- updates are done

Code:

...
13 Apr 2008 at 16.13.07,062   DEBUG (SessionId=3000637818,org.hibernate.jdbc.AbstractBatcher,401,Worker-0) []  update CUS_CONTACT set...

Thanks for your help.