Is there a JPA provider which stores in XML format and not for a RDBMS?

DataNucleues for example does it but I don't like the preprocessing (their JPA implementation is based on JDO). Are there other alternatives? The format of the XML-file doesn't really matter.

开发者_StackOverflow社区We use JPA already and store to a RDBMS. I don't need new design approach but just if there is such a solution to persist in XML. My question is not "Is it a good idea to persist with JPA to XML?"

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EclipseLink includes both JPA and JAXB support to allow both database and XML mapping. You can use JAXB to serialize an object model to a file or stream. EclipseLink also has EIS support for non-relational databases including XML data sources (an XML file adapter is included).

In general if you are just looking for a light weight database, I would recommend an embedded Java database such as Derby or HSQL.