How can i return null values to bags not initialized?

eliezerreis · **Joined:** Mon Feb 08, 2010 3:47 pm **Posts:** 3

I'm trying serialize some objects through wcf. So, for performance reason, I have some collections configured with lazy=true. However, this proxy doesn't work with wcf. So, I made a solution based on the Tim Vasil solution.

http://timvasil.com/blog14/post/2008/02 ... rnate.aspx

In his solution he force initialization of collections with lazy=true because it can't be initialized in te client. Otherwise, in my solution if i don't force fetch mode in the moment of query so the collection will not be necessary on the client. Is there any way to instantiate a a empty collection or a return null without problem?

Tim Vasil

Code:

 // Serialize persistent collections as the collection interface type
        if (obj is IPersistentCollection)
        {
            IPersistentCollection persistentCollection = (IPersistentCollection)obj;
            persistentCollection.ForceInitialization();
            obj = persistentCollection.Entries(); // This returns the "wrapped" collection
        } 

I made the code bellow but it doesn't work.

Code:

           if (obj is IPersistentCollection) {
                IPersistentCollectioncoll = (IPersistentCollection)obj;
                if (!coll.WasInitialized){
                    obj = null;
                }
            }

syndony · **Joined:** Mon Feb 15, 2010 2:39 am **Posts:** 4

how the instance variable was initialized with an instance of HashSet. This is the best way to initialize collection valued properties of newly instantiated (non-persistent) instances. When you make the instance persistent, by calling persist() for example, Hibernate will actually replace the HashSet with an instance of Hibernate's own implementation of Set. Be aware of the following errors:
Cat cat = new DomesticCat();
Cat kitten = new DomesticCat();
....
Set kittens = new HashSet();
kittens.add(kitten);
cat.setKittens(kittens);
session.persist(cat);
kittens = cat.getKittens(); // Okay, kittens collection is a Set
(HashSet) cat.getKittens(); // Error!