Consider the request "GET /root/book" and the following code:
CXF will dispatch the call to Sub.getBook().
Unfortunately, JAX-RS matching algorithm is currently written such that the call will be rejected due to the fact the matching sub-resource is expected to be immediately discarded if the current root has methods matching the same path, even though these methods (such as addBook) may have no matching HTTP verbs.
IMHO it is a JAX-RS algorithm limitation and I'm positive at the moment that this issue will be addressed as part of the JAX-RS 2.1 work. However CXF needs to support this behaviour by default for CXF to stay on the 'pure' JAX-RS 2.0 path.
The contextual property to support the users depending on the current CXF approach will be introduced