// create and configure XStream for JSON
XStream xstream = createAndConfigureXstream(new JsonOrgHierarchicalStreamDriver());
// for JSON, we use a custom converter for Maps
xstream.registerConverter(new PrimitiveKeyedMapConverter(xstream.getMapper()));
// put it into context
getContext().getAttributes().put(JSON_XSTREAM, xstream);
// create and configure XStream for XML