I bet you have some requirement of exposing the REST API inside FUSE to achieve loose coupling.
You could use CXFRS to expose your REST interface if you need to parse the datatypes sent to Java and maybe map them to something else.
Another, somewhat simpler, component is Restlet. It allows you to deal with most aspects of REST style interfaces, such as URI parsing.
Since REST is plain HTTP, in some cases you can come a long way using the servlet/http4 components, maybe to simply proxy or route HTTP requests.
In any case, read up on those components and come back with more specific questions, should you have any