Are there tools to generate a ddl schema from JDO annotated pojos?

Perhaps i'm wandering down the wrong path - I'm looking for a tool like hbm2ddl.

I currently have domain model (pojos with JDO annotations) - I need to setup t开发者_如何学Pythonhe database.

I want to experiment with a few database types - HSQLDB, Google App Engine, Oracle.

Can anyone offer advice on how to proceed?

You mean DataNucleus "SchemaTool" that generates the schema direct, or creates a DDL file ? Obviously that will not work for AppEngine since it has no "schema" and is not an RDBMS