To answer your questions, why not try something like the code snippet
below?
Cheers,
Ian
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable = "true")
public class User
{
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
@Extension(vendorName="datanucleus", key="gae.encoded-pk",
value="true")
private String sEncodedKey;
/*
// This is optional, but I use it.
@Persistent
@Extension(vendorName="datanucleus", key="gae.pk-id", value="true")
private Long loKeyID;
*/
/*
// This is optional.
// One cannot define both a "gae.pk-id" and a "gae.pk-name" in the
same class.
@Persistent
@Extension(vendorName="datanucleus", key="gae.pk-name", value="true")
private String sKeyName;
*/
// Even though this field is an array list, the accessor methods
// for this field treat the relationship of this class with the child
class
// as 1-1 (not 1-N).
// This is a work-around for datanucleus-appengine issue 165: "
// Relation.ONE_TO_ONE_BI NPE
postInsert(PersistenceCapableMapping.java:1039)"
@Persistent(mappedBy="userParent")
@Element(dependent="true")
@Order(extensions = @Extension(vendorName="datanucleus", key="list-
ordering",
value="sEncodedKey ASC"))
private ArrayList<FavAnimal> faFavAnimals = new
ArrayList<FavAnimal>();
public FavAnimal getFavAnimal()
{
FavAnimal faFavAnimal = null;
if ((faFavAnimals != null) && (!faFavAnimals.isEmpty()))
faFavAnimal = faFavAnimals.get(0);
return faFavAnimal;
}
public void setFavAnimal(FavAnimal favAnimal)
{
if (faFavAnimals == null)
faFavAnimals = new ArrayList<FavAnimal>();
if (!faFavAnimals.isEmpty())
faFavAnimals.clear();
if (faFavAnimals != null)
faFavAnimals.add(favAnimal);
}
...
}
@PersistenceCapable(identityType = IdentityType.APPLICATION,
detachable = "true")
public class FavAnimal
{
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
@Extension(vendorName="datanucleus", key="gae.encoded-pk",
value="true")
private String sEncodedKey;
@Persistent(dependent="false")
private User userParent;
...
}
FavAnimal fa = new FavAnimal();
user.setFavAnimal(fa);
fa.setUserParent(user);
pm.makePersistent(fa);
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