Hi
I just wanted to confirm that I am using the PersistenceManager in the
correct manner... I have a List of a JDO persisted class retrieved in
my Spring MVC controller as follows:
protected ModelAndView handleRequestInternal(HttpServletRequest req,
HttpServletResponse resp) throws Exception {
PersistenceManager pm =
PersistenceHelper.getPersistenceManagerFactory().getPersistenceManager
();
String query = "select from " + Feed.class.getName() + " order
by
lastNewItem desc";
List<Feed> feeds = (List<Feed>)pm.newQuery(query).execute();
pm.retrieveAll(feeds);
pm.close();
ModelAndView mv = new ModelAndView();
mv.addObject("feedList", DataUtil.getFeeds());
mv.setViewName("feeds");
return mv;
}
This is passing the List of Feed objects to the view which iterates
through and displays each. My problem is that I need to close the
PersistenceManager in this method and unless I use the pm.retrieveAll
() method, I get an org.datanucleus.exceptions.NucleusUserException:
Object Manager has been closed error.
My problem is that I don't need to load ALL of the fields in the Feed
class... in particular it owns a 1:M relationship to FeedItem and I
would rather not load all of these as well.
I have tried annotating this field in my Feed class as follows:
@Persistent(mappedBy = "feed", defaultFetchGroup="false")
private List<FeedItem> items;
... but they all get loaded anyway.
Is there any way to configure this? Alternatively, I could choose not
to close the PersistenceManager but I assume this is expensive and bad
practice?
Thanks in advance
Al.
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