initializing hibernate many-to-one relation within Set

[dendenners]

Hi,
I posted the same issue on the hibernate site, but am cross-posting here because it may be spring that I'm getting into difficulty with.
I'm having some difficulty getting a many-to-one relation initialized. I'm subclassing HibernateDaoSupport class in the class involved.
What I have is a Batch that contains a Set of transactions. In a certain method I want to load a batch using hibernate by calling the getHibernateTemplate().findByNamedParam() method, passing in the id of the batch. I also need the set of transactions in this case, which I get back by doing a left join fetch in the hql passed in to the spring method mentioned (this is the reason I use hql - I need to specify a left join fetch)
This all works fine. However here I get into trouble. Each Transaction has 2 many-to-one relations (a transactionCurrency and an errorCode) that I want initialized by this query. I thought the best way to do this was by iterating through the transactions and calling a Hibernate.initialize() for each many-to-one I was interested in initializing. However this seems only to work for the transactionCurrency many-to-one (even though the hibernate-generated select SQL for both many-to-ones appears on the console).
The code snippet below uses a hardcoded transactional callback. I've tried using a TransactionProxyFactoryBean as well with the same results.
The errorCode object is always a cglib proxy with null values for both its fields. I'm sure I'm doing something stupid here or there is a trivial mistake in my mappings or transaction. I'd be grateful if anyone could point any problem out, cause I can't see it.
Here's the spring code

    public Batch getBatchWithTransactions(final Long batchID) {
        return (Batch) getHibernateTemplate().execute(new
HibernateCallback() {
            public Object doInHibernate(final Session session) {
                Batch batch =  (Batch) session.createQuery(
                        "from myproject.dataobject.Batch b "
                        + "left join fetch b.transactions "
                        + "where b.id
= :batchID").setParameter("batchID", batchID)
                        .list().get(0);
                Iterator txns = batch.getTransactions().iterator();
                while (txns.hasNext()) {
                    Transaction t = (Transaction) txns.next();
                    Hibernate.initialize(t.getErrorCode());
                    Hibernate.initialize(t.getTransactionCurrency());
                }
                return batch;
            }
        });
    }

(relevant parts of 4 different hbm.xml files)
Batch.hbm.xml

<hibernate-mapping>
     <class name="myproject.dataobject.Batch"
       table="batch">
         <id name="id"
            column="batch_id" type="long">
             <generator class="native" />
         </id>
        <set name="transactions" inverse="true" cascade="save-update">
            <key column="batch_id" />
            <one-to-many class="myproject.dataobject.Transaction" />
        </set>
     </class>
</hibernate-mapping>

transaction.hbm.xml

<hibernate-mapping package="myproject.dataobject">
    <class name="Transaction" table="TRANSACTION">
        <id
            column="TRANSACTION_ID"
            name="id"
            type="long"
            >
            <generator class="native" />
        </id>
        <many-to-one name="batch"
            not-null="true"
            class="myproject.dataobject.Batch"
            cascade="save-update"
            >
            <column name="BATCH_ID" />
        </many-to-one>
        <many-to-one name="errorCode"
            class="myproject.dataobject.lookup.StatusCode"
            column="ERROR_CODE"
            />
        <many-to-one name="transactionCurrency"
            class="myproject.dataobject.Currency"
            column="TRANSACTION_CURRENCY_CODE"
            />
    </class>
</hibernate-mapping>

StatusCode.hbm.xml

<hibernate-mapping package="myproject.dataobject">
   <class name="StatusCode" table="STATUS_CODE">
      <id
         column="ERROR_CODE"
         name="id"
         type="integer"
      >
         <generator class="native" />
      </id>
      <property
         column="ERROR_DESCRIPTION"
         length="50"
         name="description"
         not-null="false"
         type="string"
       />
   </class>
</hibernate-mapping>

Currency.hbm.xml

<hibernate-mapping>
  <class name="myproject.dataobject.Currency"
      table="currency">
      <id name="isoCode" column="iso_code" type="integer">
          <generator class="sequence">
              <param name="sequence">acquirer_comm_seq</param>
          </generator>
      </id>
      <property name="swiftCode"
          column="swift_code"
          not-null="true"
          type="string"
          unique="false"
          />
      <property name="name"
          column="description"
          not-null="true"
          type="string"
          unique="false"
          />
      <property name="minorUnits"
          column="minor_units"
          not-null="true"
          type="integer"
          unique="false"
          />
  </class>
</hibernate-mapping>

[dendenners]

Found the problem. getters in the offending unpopulated object were marked as final, which meant that hibernate could not proxy them.

[Costin Leau]

As a work around specify inside the mapping the access to be directly on the field (thus bypassing the getter/setter).

[Colin Yates]

BTW: If you tell Hibernate to populate the field, how does Hibernate do dirty detection?

[Costin Leau]

That's something internal to Hibernate; AFAIK the proxy will not override the method and will do field interception (as opposed to method interception).

[Colin Yates]

(OFF TOPIC): I see. I assumed (actually guessed ) that hibernate overrode the accessors and set a dirty flag on the setters.

I suppose it must be a bit more sophisticated.

Thanks dude