如何使用Play提供XML和JSON！ 2.0

I'm toying around with building a simple application to get my feet wet with Play! 2.0. I would like to be able to serve my resources as XML (ATOM feed, really) and JSON. I know how to do it in 1.2.x, but that way doesn't seem to work with 2.0. Does anyone know how to do it? Examples would be much appreciated.I'm toying around with building a simple applic