On Apr 10, 2009, at 11:10 AM, Stamenkovic Florijan wrote:
This looks quite interesting... JavaPersistence's API makes much more sense to me then JDO's. I have some questions about JP however, if you have a moment to answer them:
JPA replaces JDO in the EJB spec I believe.
1. How complicated is the glue layer between JP, and MSAccess / Derby?
JPA is just a spec so it depends which implementation you pick, but most of them are fairly heavy. Toplink (now EclipseLink), Hibernate, JPOX and others all have implementations. Cayenne will be JPA compliant in v3 supposedly.
2. Do you have to define the database schema on both layer manually? Or is there some sort of an automation involved in this process?
They all use mapping files of one type or another. NetBeans and JBuilder have (mostly) automated building them and there's probably other tools.
3. Are there any significant ORM-feature differences between WO and JP?
There are things we take for granted in EOF that need manual attention in JPA like validation, sequences, nested contexts, etc. Most implementations extend the JP API to handle some of these.
4. Can JP conveniently deliver info on the database shema? Info such as a list of properties, attributes, relationships, inverse relationships, attribute classes... Or maybe does one have to manually extract that from the annotations using reflection?
Dunno...
5. JP seems to rely heavily on annotations. I have never worked much with annotations... What are your experiences with this approach?
I don't think it's much of a decision criteria, they just are. If you ever worked with, say, early versions of Hibernate *everything* was in XML. Annotations just move some of the static metadata out and into the code.
John _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to [email protected]
