http://code.google.com/appengine/docs/java/datastore/relationships.html#Owned_One_to_One_Relationships
"You create a bidirectional one-to-one relationship using fields on
both classes, with an annotation on the child class's field to declare
that the fields represent a bidirectional relationship. The field of
the child class must have a @Persistent annotation with the argument
mappedBy = "...", where the value is the name of the field on the
parent class."
>From what I see, you have it backwards, with the annotation in the
parent class.
Jake
On Feb 24, 4:26 am, Anton Klotz <dipl.ing.akl...@googlemail.com>
wrote:
> Hi,
>
> could please somebody tell me, what I'm doing wrong here?
>
> Here is one child datastructure I want to persist:
>
> @PersistenceCapable
>
> public class OfferDetails {
>
> @PrimaryKey
> @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> private Key mId;
>
> @Persistent
> private String mOfferDescription;
>
> @Persistent
> private Offer mOffer;
>
> public OfferDetails ()
> {
>
> }
>
> public OfferDetails (String offerDesc)
> {
> this ();
> mOfferDescription = offerDesc;
> }
>
> }
>
> And here is the parent
>
> @PersistenceCapable(identityType = IdentityType.APPLICATION,
> detachable="true")
>
> public class Offer {
> @PrimaryKey
> @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
> private Key mId;
>
> @Persistent(mappedBy="mOffer")
> private OfferDetails mOfferDetails;
>
> public Offer( OfferDetails offerDetails)
> {
> this();
> mOfferDetails = offerDetails;
> }
>
> }
>
> Here is the presistance routine:
>
> public class OfferDataAccess {
> private static final long serialVersionUID = -7037344095742126014L;
> private PersistenceManager pm;
>
> public OfferDataAccess ()
> {
> pm = PMF.get().getPersistenceManager();
> }
>
> public void persistOffer (Offer offer)
> {
> pm.currentTransaction().begin();
> try {
> pm.makePersistent(offer);
> pm.currentTransaction().commit();
> } finally {
> if (pm.currentTransaction().isActive())
> pm.currentTransaction().rollback();
> pm.close();
> }
> }
>
> And here is the call of the persistance routine:
> class CreateOfferActionCommand
> {
> public void execute() {
> mOfferDB = new OfferDataAccess ();
> mOffer = new Offer (mOfferDetails);
> mOfferDB.persistOffer (mOffer);
>
> }
> }
>
> Now if I run this code, I get following errormessage:
>
> java.lang.IllegalStateException: Primary key for object of type
> OfferDetails is null.
> at
> org.datanucleus.store.appengine.EntityUtils.getPkAsKey(EntityUtils.java:
> 152)
> at
> org.datanucleus.store.appengine.DatastoreFieldManager.getKeyForObject(DatastoreFieldManager.java:
> 625)
> at
> org.datanucleus.store.appengine.DatastoreFieldManager.getParentKeyFromParentField(DatastoreFieldManager.java:
> 634)
> at
> org.datanucleus.store.appengine.DatastoreFieldManager.establishEntityGroup(DatastoreFieldManager.java:
> 591)
> at
> org.datanucleus.store.appengine.DatastorePersistenceHandler.insertPreProcess(DatastorePersistenceHandler.java:
> 338)
> at
> org.datanucleus.store.appengine.DatastorePersistenceHandler.insertObjects(DatastorePersistenceHandler.java:
> 246)
> at
> org.datanucleus.store.appengine.DatastorePersistenceHandler.insertObject(DatastorePersistenceHandler.java:
> 235)
> at
> org.datanucleus.state.JDOStateManagerImpl.internalMakePersistent(JDOStateManagerImpl.java:
> 3185)
> at
> org.datanucleus.state.JDOStateManagerImpl.makePersistent(JDOStateManagerImpl.java:
> 3161)
> at
> org.datanucleus.ObjectManagerImpl.persistObjectInternal(ObjectManagerImpl.java:
> 1298)
> at
> org.datanucleus.ObjectManagerImpl.persistObject(ObjectManagerImpl.java:
> 1175)
> at
> org.datanucleus.jdo.JDOPersistenceManager.jdoMakePersistent(JDOPersistenceManager.java:
> 669)
> at
> org.datanucleus.jdo.JDOPersistenceManager.makePersistent(JDOPersistenceManager.java:
> 694)
> at
> com.sparradar.server.datamodel.offer.OfferDataAccess.persistOffer(OfferDataAccess.java:
> 29)
> at
> com.sparradar.server.action.actioncommands.CreateOfferActionCommand.execute(CreateOfferActionCommand.java:
> 60)
> at
> info.rk.vaadinapp.manager.urldispatching.URLActionDispatcher.handleURI(URLActionDispatcher.java:
> 90)
> at com.vaadin.ui.Window.handleURI(Window.java:358)
> at
> com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleURI(AbstractCommunicationManager.java:
> 1830)
> at
> com.vaadin.terminal.gwt.server.CommunicationManager.handleURI(CommunicationManager.java:
> 311)
> at
> com.vaadin.terminal.gwt.server.AbstractApplicationServlet.handleURI(AbstractApplicationServlet.java:
> 912)
> at
> com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:
> 471)
> at
> com.vaadin.terminal.gwt.server.GAEApplicationServlet.service(GAEApplicationServlet.java:
> 231)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
> at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:
> 487)
> at org.mortbay.jetty.servlet.ServletHandler
> $CachedChain.doFilter(ServletHandler.java:1093)
> at
> com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:
> 51)
> at org.mortbay.jetty.servlet.ServletHandler
> $CachedChain.doFilter(ServletHandler.java:1084)
> at
> com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:
> 43)
> at org.mortbay.jetty.servlet.ServletHandler
> $CachedChain.doFilter(ServletHandler.java:1084)
> at
> com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:
> 121)
> at org.mortbay.jetty.servlet.ServletHandler
> $CachedChain.doFilter(ServletHandler.java:1084)
> at
> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:
> 360)
> at
> org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:
> 216)
> at
> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:
> 181)
> at
> org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:
> 712)
> at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:
> 405)
> at
> com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:
> 70)
> at
> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
> 139)
> at com.google.appengine.tools.development.JettyContainerService
> $ApiProxyHandler.handle(JettyContainerService.java:352)
> at
> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
> 139)
> at org.mortbay.jetty.Server.handle(Server.java:313)
> at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:
> 506)
> at org.mortbay.jetty.HttpConnection
> $RequestHandler.headerComplete(HttpConnection.java:830)
> at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
> at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
> at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
> at
> org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
> 396)
> at org.mortbay.thread.BoundedThreadPool
> $PoolThread.run(BoundedThreadPool.java:442)
>
> Could you please tell me, what I'm doing wrong here?
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