WSO2- MSF4J to parse XML dynamically

Question

I am in a requirement to develop a middleware API on MSF4J framework which shoudl be able to accept XML as input and send a transformed XML back to client? Could see examples with json as input like the below snippet but not with XML anywhere?

How to receive and parse XML dynamically?.

With JSON code :-

import com.google.gson.JsonObject;
@POST
@Path("/orderpizza")
public Response post(JsonObject orderDetailsJson) { }

P.S- not with XML file in local system.