How to implemnt Lazy initialization in Hibernate?

windhong · **Joined:** Wed Apr 08, 2009 4:36 pm **Posts:** 1

In my non-web Hibernate project:

Code:

public class ImageSet {

    private Set<GeneralImage> referencedImages;

}

ImageSet imageSet = getImageSet("SeriesID");

Set<GeneralImage> images = imageSet.getReferencedImages();

In hibernate configuration file, set lazy="true" and will meet exception: "LazyInitializationException"

Because in getImageSet method, close the session

Code:

public static ImageSet getImageSet(String UID){

    Session session = HibernateUtil.getSessionFactory().openSession();

    ImageSet imageSet = findImageSet(UID, session); 

    session.close();

    return imageSet;

}

If I set lazy="false", and it will don't show exception, but I want to set lazy="ture", because of performance. I want to separate Dao layer and application layer, and don't want to let hibernate session appears in application layer, so I want to know how to solve this problem? Thanks!

kochcp · **Posted:** Thu Apr 09, 2009 8:39 am

When you need to then load your referencedImages, pass the imageSet back into your dao layer. And there you'll need to reassociate imageSet with another open session and then get those referencedImages.

And if you're merely doing it immediately after your initial load like your example shows, why even set it to lazy = "true"