I´m using the Hibernate version 3.0.5

One of my mapping files is:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping default-cascade="none">
<class name="com.embratel.confserv.order.domain.ServiceTypeImpl" table="SERVICE_TYPE" dynamic-insert="false" dynamic-update="false">
<id name="id" type="java.lang.Long" unsaved-value="null">
<column name="ID" sql-type="NUMBER(19)"/>
<generator class="sequence">
<param name="sequence">SERVICE_TYPE_SEQ</param>
</generator>
</id>
<property name="type" type="java.lang.String">
<column name="TYPE" not-null="true" unique="true" sql-type="VARCHAR2(255)"/>
</property>
<property name="queueName" type="java.lang.String">
<column name="QUEUE_NAME" not-null="true" unique="false" sql-type="VARCHAR2(255)"/>
</property>
<set name="translators" order-by="SERVICE_TYPE_FK" lazy="true" fetch="select" inverse="false">
<key foreign-key="TRANSLATOR_SERVICE_TYPE_FKC">
<column name="SERVICE_TYPE_FK" sql-type="NUMBER(19)"/>
</key>
<one-to-many class="com.embratel.confserv.order.domain.TranslatorImpl"/>
</set>
<set name="validators" order-by="SERVICE_TYPE_FK" lazy="true" fetch="select" inverse="false">
<key foreign-key="VALIDATOR_SERVICE_TYPE_FKC">
<column name="SERVICE_TYPE_FK" sql-type="NUMBER(19)"/>
</key>
<one-to-many class="com.embratel.confserv.order.domain.ValidatorImpl"/>
</set>
</class>
</hibernate-mapping>


My class is like this:
package com.embratel.confserv.order.domain;

import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.LockMode;
import com.embratel.confserv.domain.AbstractDAO;

/**
*
*/
public abstract class ServiceType
extends com.embratel.confserv.domain.AbstractEntity implements java.io.Serializable
{



/**
* The serial version UID of this class. Needed for serialization.
*/
private static final long serialVersionUID = 2948988219572588067L;

private java.lang.String type;

... getter and setter for type

private java.lang.String queueName;

... getter and setter for queueName

private java.lang.Long id;

... getter and setter for id

private java.util.Collection translators = new java.util.HashSet();

/**
*
*/
public java.util.Collection getTranslators()
{
Session session = AbstractDAO.currentSession();
if(getId() != null) {
//session.saveOrUpdate(this);
//session.lock(this, LockMode.NONE);
Hibernate.initialize(this.translators);
}
//session.flush();
AbstractDAO.closeSession();
return translators;
}

public void setTranslators(java.util.Collection translators)
{
this.translators = translators;
}

private java.util.Collection validators = new java.util.HashSet();

/**
*
*/
public java.util.Collection getValidators()
{
Session session = AbstractDAO.currentSession();
if(getId() != null) {
//session.saveOrUpdate(this);
//session.lock(this, LockMode.NONE);
Hibernate.initialize(this.validators);
}
//session.flush();
AbstractDAO.closeSession();
return validators;
}

public void setValidators(java.util.Collection validators)
{
this.validators = validators;
}

}


I get the persistent object via this way:
public ServiceType selectByType(String serviceType) throws DAOException {
Session session = null;
try {
session = currentSession();

org.hibernate.Query qry = session
.createQuery("from com.embratel.confserv.order.domain.ServiceType st where st.type = ?");
qry.setString(0, serviceType);
List res = qry.list();
Iterator it = res.iterator();
if (it.hasNext()) {
ServiceTypeImpl next = (ServiceTypeImpl) it.next();
return next;
}
throw new DAOException("Não foi encontrado um tipo de serviço '"
+ serviceType + "'");

} catch (HibernateException h) {
throw new DAOException(h);
} finally {
try {
closeSession();
} catch (HibernateException e) {
throw new DAOException(e);
}
}
}

I have a class that has a association one-to-many for another. When I get the first class, I don´t have the second yet (because of lazy initialization). When I try to get the second, I use the initialize method but using another session. And then, I got the error:

17:33:09,796 INFO [STDOUT] com.embratel.confserv.order.service.ServiceManagerException: org.hibernate.HibernateException: disconnected session

When I try to use the methods lock OR saveOrUpdate to associate the object to the session, I got the error:

16:48:17,687 INFO [STDOUT] javax.ejb.TransactionRolledbackLocalException: Unexpected Error
java.lang.OutOfMemoryError: Java heap space
; CausedByException is:
Unexpected Error
java.lang.OutOfMemoryError: Java heap space

Anybody can help me, please?
Thanks in advance,
Luciana.

There could be different causes to your problem.

First I would look at how many objects is your query loading in memory and what the max heap size of the JVM is.

Also, could you show the code you're using to reattach objects to the session ?