Hi, best, you have a look at the documentation:
http://people.apache.org/~mprudhom/openjpa/site/openjpa-project/manual/ref_guide_pc_enhance.html OpenJPA classes need to be enhanced to provide lazy fetching. Else there will always been used eager fetching, which could be the cause of your problem. -------- Original-Nachricht -------- > Datum: Fri, 15 May 2009 15:26:43 +0200 > Von: "Morten O. Hansen" <morte...@gmail.com> > An: users@openjpa.apache.org > Betreff: Re: Creating nodes with parents > Hi > > Thank for your quick response :) Sorry for my ignorance, but what do you > mean by enhancing the classes? > > //Morten > > On Fri, May 15, 2009 at 15:21, <naomi-...@gmx.de> wrote: > > > Hi, > > > > as far as I know, TopLink has a maximum fetching depth of 2 by default > and > > OpenJPA has an infinite fetching depth, which could lead to recursions > in > > the worst case if you use eager fetching. > > I am wondering why this also happens with lazy fetching - did you forget > to > > enhance your classes? > > > > You can set the maximum fetching depth in your persistence.xml by > setting > > the following property: > > > > <property name="openjpa.MaxFetchDepth" value="2"/> > > > > I hope this helps :) > > > > -------- Original-Nachricht -------- > > > Datum: Fri, 15 May 2009 14:58:03 +0200 > > > Von: "Morten O. Hansen" <morte...@gmail.com> > > > An: users@openjpa.apache.org > > > Betreff: Creating nodes with parents > > > > > Hi all > > > > > > I'm trying to create a Node class, where every Node has a pointer to a > > > parent Node (or null if there is none). > > > > > > A simplified view of the Node-class looks like this: > > > > > > @Entity > > > public class Node { > > > @Id protected long id; > > > @ManyToOne(fetch=LAZY) > > > protected Node parent; > > > protected String name; > > > protected String displayName; > > > > > > // setters / getters.. > > > } > > > > > > And this was working correctly in TopLink (I think they just do > infinite > > > recursion depth), but in OpenJPA i get something that looks like > > recursion > > > errors. > > > > > > Is there a better way of doing this? I have implemented a hack just > using > > > long parentId instead, but that kinda sucks when you are deleting and > > > updating nodes. > > > > > > I know there is something called FetchGroups in OpenJPA, but i > couldn't > > > really get them to work and I want to have entities that hopefully > isn't > > > tied down to OpenJPA. > > > > > > -- > > > Morten > > > > -- > > Neu: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate + > > Telefonanschluss für nur 17,95 Euro/mtl.!* > > http://dslspecial.gmx.de/freedsl-surfflat/?ac=OM.AD.PD003K11308T4569a > > -- Neu: GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate + Telefonanschluss für nur 17,95 Euro/mtl.!* http://dslspecial.gmx.de/freedsl-surfflat/?ac=OM.AD.PD003K11308T4569a
