This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
If you consider JAX-RPC to be a XML-RPC solution, then I think that it still exists in the Java APIs.
I am sure of JAX-WS being able to do pure XML over HTTP, without using SOAP envelopes, but I am not sure if JAX-RPC can do the same.
If JAX-RPC does not satisfy your requirements, then I do not know of any XML-RPC solutions in the standard Java API.