I am encountering an error while demarshalling a JSON object as input to a JAX-RS method. After some tinkering, the error seems to be due to the XmlNsMap defined for the output not being applied to the input.

org.jboss.resteasy.plugins.providers.jaxb.JAXBUnmarshalException: javax.xml.bind.UnmarshalException
 - with linked exception:
[com.sun.istack.SAXParseException2; columnNumber: 0; unexpected
element (uri:"", local:"ejava.link"). Expected elements are <{http://ejava.info}link>]

Is there something similar to the ContextResolver<JAXBContext> that has to be done for JSON XmlNsMaps?

The RESTEasy JSON examples generate data (which I can do) but none consume data. I have gotten it to work by injecting a String and demarshalling the object thru the Jettison APIs. I can also get the
manual approach to generate the same error message – which leads me to think the input/demarshaller for JSON needs more than the @Mapped annotation.

• I am working with a simple Link class in the "http://ejava.info" namespace.

  package ejava.util.rest;
  @XmlRootElement(name="link", namespace="http://ejava.info")
  @XmlType(name="LinkType", namespace="http://ejava.info")
  public class Link {
     ...
  }
  

• I have attempted to pass the JSON object straight into the method and have RESTEasy do the demarshalling. I have added the @Mapped/@XmlNsMap annotations for the used namespace. This has allowed
  me to generate Link objects successfully.

     @PUT @Path("attributes")
     @Consumes(MediaType.APPLICATION_JSON)
     @Produces(MediaType.APPLICATION_JSON)
     @Mapped(namespaceMap = {
         @XmlNsMap(namespace = "http://ejava.info", jsonName = "ejava"),
     })
     public Response putLinkJSON(Link link) //String jsonString)
             throws JSONException, XMLStreamException, JAXBException {
         link.setHref(uriInfo.getRequestUri());
         link.setType(MediaType.APPLICATION_XML);
         return Response.ok(link, MediaType.APPLICATION_JSON).build();
     }
  

• When I PUT my JSON object to the method...

PUT /jaxrs-representations-dmv-war6/data/attributes HTTP/1.1
Content-Type: application/json
Accept: application/json
Content-Length: 30
Host: dmv.ejava.info:9092
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.1.3 (java 1.5)

{"ejava.link":{"@rel":"self"}}

... it reports the following error

 -Failed executing PUT /data/attributes
org.jboss.resteasy.plugins.providers.jaxb.JAXBUnmarshalException: javax.xml.bind.UnmarshalException
 - with linked exception:
[com.sun.istack.SAXParseException2; columnNumber: 0; unexpected element (uri:"", local:"ejava.link"). Expected elements are <{http://ejava.info}link>]
       at org.jboss.resteasy.plugins.providers.jaxb.AbstractJAXBProvider.readFrom(AbstractJAXBProvider.java:125)

• When I inject the JSON object into a String and manually demarshal the JSON. It works (see the 200 reply below)

     @PUT @Path("attributes")
     @Consumes(MediaType.APPLICATION_JSON)
     @Produces(MediaType.APPLICATION_JSON)
     @Mapped(namespaceMap = {
         @XmlNsMap(namespace = "http://ejava.info", jsonName = "ejava"),
     })
     public Response putLinkJSON(String jsonString)
             throws JSONException, XMLStreamException, JAXBException {
  
         JAXBContext ctx = JAXBContext.newInstance(Link.class);
         Configuration config = new Configuration();
         Map<String, String> xmlToJsonNamespaces = new HashMap<String,String>();
         xmlToJsonNamespaces.put("http://ejava.info", "ejava");
         config.setXmlToJsonNamespaces(xmlToJsonNamespaces);
         MappedNamespaceConvention con = new MappedNamespaceConvention(config);
  
         JSONObject obj = new JSONObject(jsonString);
         XMLStreamReader xmlStreamReader = new MappedXMLStreamReader(obj, con);
         Unmarshaller unmarshaller = ctx.createUnmarshaller();
         Link link = (Link) unmarshaller.unmarshal(xmlStreamReader);
  
         link.setHref(uriInfo.getRequestUri());
         link.setType(MediaType.APPLICATION_XML);
         return Response.ok(link, MediaType.APPLICATION_JSON).build();
     }
  

HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
Server: Jetty(6.1.26)

{"ejava.link":{"@href":"http:\/\/dmv.ejava.info:9092\/jaxrs-representations-dmv-war6\/data\/attributes","@rel":"self","@type":"application\/xml"}}

• When I comment out the Map in the working code...

         Map<String, String> xmlToJsonNamespaces = new HashMap<String,String>();
         //xmlToJsonNamespaces.put("http://ejava.info", "ejava");
         config.setXmlToJsonNamespaces(xmlToJsonNamespaces);
  

...I get an error message similar to the one from the original case.

[com.sun.istack.SAXParseException2; columnNumber: 0; unexpected element (uri:"", local:"ejava.link"). Expected elements are
<{http://ejava.info}link>]
       at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:434)
       at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:371)
       at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:341)
       at ejava.examples.jaxrsrep.handlers.JSONHandlerDemoRS.putLinkJSON(JSONHandlerDemoRS.java:100)

This leads me to think that I need to register something similar to the ContextResolver that I have done for other JAXB cases – however, I haven't located any documentation on how I can help setup the
Jettison demarshaller.