Q: How to Mark collection as loaded (or Tree structure)

montechristos · **Joined:** Fri Jun 08, 2007 4:20 am **Posts:** 13

Hello all,

We have a tree structure:

Code:

class Location {
   @OneToMany(cascade = CascadeType.ALL, mappedBy = "parentLocation", fetch = FetchType.LAZY)
   protected SortedSet<Location> childLocations = new TreeSet<Location>();
}

we load all the Locations in one query:

Code:

cache = session.createQuery("from Location");

and then we fill the tree structure like this:

Code:

Location parent;
   for (Location loc : cache) {
      parent = loc.getParentLocation();
      if (parent != null) 
         parent.addChildLoc(loc);
   } 

Now the question is, how do we mark the 'childLocations' collection as loaded so Hibernate does not try to run a query to load it?

Many thanks

montechristos · **Joined:** Fri Jun 08, 2007 4:20 am **Posts:** 13

Anyone?

montechristos · **Joined:** Fri Jun 08, 2007 4:20 am **Posts:** 13

Bump!

Anyone?

montechristos · **Joined:** Fri Jun 08, 2007 4:20 am **Posts:** 13

Bump?

rossj · **Joined:** Fri Sep 26, 2003 1:50 pm **Posts:** 9

Hi,

I haven't seen any sign that you can tell a collection to 'consider' itself initialized.

However, I do wonder whether you aren't better off just managing the collection yourself (i.e. mark it as transient). Since you are loading all nodes and populating the child collections by scanning the loaded nodes, there is not much left that Hibernate does for you (except to generate heaps of unwanted database queries). The only thing that springs to mind is cascading. You would have to persist each tree node explicitly for example.

/Ross.

kochcp · **Posted:** Thu Apr 09, 2009 8:35 am

if you're loading it manually, why don't you just remove the association in the mapping file.

montechristos · **Joined:** Fri Jun 08, 2007 4:20 am **Posts:** 13

Hi and thanks for the answers.

The idea was not to deal with the collection on our own. Marking it transient or removing the mapping is not exactly what we are trying to do.

The idea was to load the hierarchy, attach the parent to the child in memory, and, for each object, make Hibernate think that it has loaded the particular collection. This way, you would have the benefits of Hibernate dealing with the collection from that moment onwards.

Hibernate uses its own Collection classes to intercept add/remove. Maybe I can cast my Collection to this and try to set its loaded flag...?