JPA and Android… here is a solution to the problem.
JPA and Android
I plan to use Google App Engine to communicate with Android apps. I plan to use Objectify, which uses JPA annotations and serializes them using the built-in XML library. What if I want to use the same object on both ends, annotations (e.g. @Id, etc.)?
Starting with version 4, Objectify no longer uses JPA/JDO annotations.
The bad thing is that annotation-only jars are not provided in the default Objectify distribution. You need to check its source and build the “client-jar” nant target you want to put into your Android application.