I'm an experienced performance test analyst working basically on validating the non functional requirements like response time and throughput using hp loadrunner.
With agile and continuous testing in place my organisation wants us to learn programming to contribute to agile teams.
With some core java knowledge should I focus on more traditional java paths like hibernate /webservices/struts
Or go with more modern Hadoop framework or scala.
I think you want to start with core Java, JUnit, Selenium and HTMLUnit. This will let you immediately use your testing expertise. It will also let you pair program with someone who already knows one of the technologies you mentioned.
Beyond that, I think you should ask what technologies these agile teams use at your organization. That way you can start with what is most valuable there.