Need: take in XML and save data to database.

Currently using: JAXB to convert the XML Schema to java classes. Then I intend to use JPA to persist the objects marshalled by JAXB. 

Problem: I want something to bridge the gap. After JAXB generates the Java classes I have to manually annotate all java.util.Date fields with @Temporal; I have to put @Entity on the top of every generated class...etc.

I came across Hyperjaxb. But I can find little documentation on it, and can't get it to work. 

I am open to completely different approaches. This seems like it would be a common problem, so maybe there is a generic solution.