EntityManager tuning to get only a few Items from a nested c

[heinrich]

Hi,


today i ran into a new problem.
I have a n2m relation between to tables.
class DrugCategory <-- n2m --> class Drug

if i obtain one DrugCategory with the EntityManager and want to load
the nested Drug objects to that Category JBoss has a lot of work to do, because there are nealry 10000 of the nested Drug-Objects.
I do Lazy-Loading and want only to get about the first 20 of the nested Drug-Objects.
How can i get this way?

I built a loop like

 DrugCategory cat = em.find(DrugCategory.class, catId);

 Collection <Drug>dc = cat.getDrugs();
 Collection <Drug> newDc = new ArrayList<Drug>();
 int i = 0;
 for (Iterator iter = dc.iterator(); iter.hasNext() && (i < 10);i++) {
 newDc.add((Drug) iter.next());
 }

the loop should end after 10 cyles. It might do that, but Jboss is still reading _all_ the nested objects from the database.

How can i achieve this?

thanks for your help

martin

[epbernard]

use a collection filter, this is Hibernate specific though