Thursday, March 26, 2009

Using JSON with JAXB in new Jersey 1.0.2

Jersey 1.0.2 was released in early February and I just got around to updating to it. I was quite excited to read about the new support for JAXB marshalling to JSON formats (this was introduced I believe in an earlier release but not well detailed). Jakub Podlesak has some nice articles on this functionality on his blog and would recommend reading them. One thing I found, is initially I attempted to use the MAPPED_JETTISON notation in the JSONConfiguration which worked fine with Java JDK 1.6u10. However when I changed this to Natural notation to support my GXT application expected output, I recieved the following error:

javax.xml.bind.JAXBException: property "retainReferenceToInfo" is not supported 
   at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:63) 
   ...


Upon re-reading the dependency notes of Jersey, I noticed the following note: "This module depends on the JAXB reference implementation version 2.1.10 or greater, and such a version is required when enabling support for the JAXB natural JSON convention..." . The version of JAXB shipped with JDK 1.6 is not at a high enough level to support this functionality. Fortuantely the workaround to get this to work is pretty easy if you following the following steps:
  1. Download the JAXB jar from the Jersey depenendencies: jaxb-api-2.1.jarand save this to a local location.
  2. Copy the jaxb-api-2.1.jar to the jre/lib/endorsed folder of your JRE or JDK installation. You may need administrative privileges on some platforms.
  3. Restart eclipse (or other IDE).
  4. In your project class path, include the other JAXB jar files listed under the "non maven developers require... section of the JAXB portion of the document

Information on the endorsed libraries is available here.

1 comment:

Farhan Shaikh said...

I have already added "jaxb-api-2.1.jar" in jboss libs. But still it throws the exception while initializing custom JAXBContextResolver.

Any idea, What's wrong over here ???