Hi,
Regarding generic methods for presistance, has anybody been doing
that?
Like this for example:
public static <T> T readDataObject(Class<T> type, Long id) {
Object object = null;
PersistenceManager pm = PMF.get().getPersistenceManager();
pm.setDetachAllOnCommit(true);
try {
object = pm.getObjectById(type,id);
} finally {
pm.close();
}
return type.cast(object);
}
You call it like this:
Beverage b = PersistenceHandler.readDataObject(Beverage.class,
beverageId);
Will this kind of code work?
Thanks.
FF
On Sep 1, 11:54 am, funkforce <[email protected]> wrote:
> Hi,
>
> First of all, thanks for posting, it really helps me.
>
> objectuser : Good post and the link was really nice.
> Albert Attard : Thanks for the examples, it shows that you have to
> wright lots of code to manage your own relationships (which I was
> trying to avoid).
> leszek: This is what I did and I was trying to avoid to handle
> persistence issues as much as I could.
>
> I will re-model and start over and see how I should go on.
>
> Thanks.
>
> FF
>
> On Sep 1, 9:52 am, leszek <[email protected]> wrote:
>
>
>
> > You can follow something like that
>
> > class Parent {
> > ....
> > @Persistent
> > private List<Long/Key> childList;
>
> > // non Persistent
> > private List<Child> list;
> > ...
>
> > }
>
> > class Child {
>
> > �...@primarykey
> > private Long/Key key;
> > ...
>
> > }
>
> > // before save Parent
> > private void beforeSave(EntityManager em,Parent pa) {
> > if (pa.getList() != null) {
> > List<Long> chList = new ArrayList<Long>();
> > for (Child ch : pa.getList) {
> > pm.makePersistent(ch);
> > pm.flush();
> > chList.add(ch.getKey());
> > }
> > pa.setChildList(chList);
> > }
> > }
>
> > private void afterLoad(EntityManager em,Parent pa) {
> > List<Child> chList = new ArrayList<Child>();
> > for (Long key : pa.getChildList()) {
> > Child ch = pm.getObjectById(Child.class,key);
> > chList.add(ch);
> > }
> > pa.setList(chList);
> > }
>
> > PersistenManager pm;
> > ....
>
> > // main service
> > Parent pa = pm..getObjectById(...)
> > afterLoad(pm,pa);
> > ...
> > ...
> > beforeSave(pm,pa);
> > pm.makePersistent(pa);
>
> > List<Parent> pList = pm.queryExecute();
> > for (Parent pa : pList) {
> > afterLoad(pm,pa);
> > }
> > ...
> > // etc
>
> > In order to avoid repeating the same beforeSave and afterLoad for all
> > Entity classes having "onowned" relationship you can apply Annotation
> > and, by the use of reflection, develop generic approach for all
> > classes having this feature.- Hide quoted text -
>
> - Show quoted text -
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