-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 jd wrote: [...] > I have a structure similar to this this: [...] > class Zoo > class Zebra implements Animal > class Donkey implements Animal [...] > javax.jdo.JDOUserException: Field "animal" is declared as a reference > type (interface/Object) but no implementation classes of "Animal" have > been found!
JDO on App Engine doesn't support polymorphism, as I understand it, which means you have to store your Zebras and Donkeys separately. I take it that what you want is a mixed bag of Animals of differing objects? The only way I found of doing that was to manually serialise my objects and store them in Blobs. It's not as hard as it looks, as the low-level API is quite nicely designed, but you do need to explicitly pull fields you want indexed out of the object before serialisation and store them as indexable properties on the entity. - -- ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── │ │ "People who think they know everything really annoy those of us who │ know we don't." --- Bjarne Stroustrup -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFKkVCdf9E0noFvlzgRAmmBAJwIHs8T5Qy5t0FgQ/ik4oTdOca1rACg0Oy1 IzwfB2MUttjgJZMdgAetr38= =U8uT -----END PGP SIGNATURE----- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~----------~----~----~----~------~----~------~--~---
