Its great to see Wildfly 8.0 making it so much easier to work with BOTH XML and JSON representations from a common set of JAXB classes without any extra plumbing or configuration of different JAXB run time implementation
All you need to do is
- Just return the JAXB objects from your business methods within the JAXRS resource classes
- Set the HTTP Accept header to application/json
Simple business method returning the JAXB class
The JSON result
You might also be interested in JAX-RS 2.0 : Custom Content Handling
Head in the clouds 