I'm using jdk1.3.1_09 with Hibernate 2.1.2.

I'm getting the following exception when I'm working with a collection were the parent object has been evicted.

LazyInitializationException:? - Failed to lazily initialize a collection - no session or session was closed

The problem with this is that if I'm going to work with lazy initialization I can't evict the objects. Lazy Initialization is important so I can partially load objects and not all their relations with other objects.

I need to evict my objects so Hibernate doesn't serialize the objects in a flush operation if they have been modified. This is also important when you're working with Oracle CLOBs and BLOBs.

Isn't there a way that I can evict my objects and use LazyInitialization???
or
Is there a way that I can disable the serialization of modified objects when the flush operation occurs???

repost

Please be more specific with your description (a smalll piece of code is better than long english speak).

Hi emmanuel

Thanks for the reply. Here is the example code:

SQL:

create table parent (id number (20) primary key, name varchar2 (255))
create table child (id number (20) primary key, name varchar2 (255), parent_id number (20));
create table sequences (next_value number (20));

Parent.java

public class Parent
{
protected long id;
protected String name;
protected List childs;

public Parent()
{
}

public long getId()
{
return id;
}

public void setId(long newId)
{
id = newId;
}

public String getName()
{
return name;
}

public void setName(String newName)
{
name = newName;
}

public List getChilds()
{
return childs;
}

public void setChilds(List newChilds)
{
childs = newChilds;
}
}

Child.java

public class Child
{
protected long id;
protected String name;

public Child()
{
}

public long getId()
{
return id;
}

public void setId(long newId)
{
id = newId;
}

public String getName()
{
return name;
}

public void setName(String newName)
{
name = newName;
}
}

Test.java

Transaction transaction;
Configuration configuration = new Configuration ();
SessionFactory factory;
Session session;
Parent parent;
Child child;

configuration.addClass (Parent.class);
configuration.addClass (Child.class);

factory = configuration.buildSessionFactory ();
session = factory.openSession ();

parent = new Parent ();
parent.setName ("Example");

transaction = session.beginTransaction ();
session.saveOrUpdate (parent);
transaction.commit ();
session.evict (parent);

parent = (Parent) session.find ("from Parent where name = ?", "Example", Hibernate.STRING).get (0);
session.evict (parent);

child = new Child ();
child.setName ("Example Child");

parent.getChilds ().add (child); // Here it throws the Exception

This is expected, the collection has not been init and you detached the object, so Hibernate can't load the collection.
Either, reattach the parent object, init the colelction before evicting it.

Emmanuel

Thanks for the quick reply.

The workarounds that you provide are very good but I can't use them in my project because the interface can change this objects without accesing the Hibernate session.

So the only way I can use LazyInitialization is to eliminate the session.evict line but I can't because Hibernate will serialize any updated objects in the session cache in a flush operation.

Do you know by any chance if I can disable this option?

Thanks for the help

session.setFlushMode(FlushMode.NEVER);