How to create java object from 'anyType' returned from service using JAXB?

A web service is returning an object defined by the WSDL to be:

<s:complexType mixed="true"><s:sequence><s:any/></s:sequence></s:complexType>

When I print out this object's class info, it comes up as:

class com.sun.org.apache.xerces.internal.dom.ElementNSImpl

But I need to unmarshall this object as an object of the following class:

@XmlAccessorType(XmlAccessType.FIELD) 
@XmlType(name = "", propOrder = {
        "info",
        "availability",
        "rateDetails",
        "reservation",
        "cancellation",
        "error" }) 
@XmlRootElement(name = "ArnResponse") 
public class ArnResponse { }

I know the response is correct, since I know how to marshall this object's XML:

Marshaller m = jc.createMarshaller();
m.setProperty( Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE );
m.marshal(rootResponse, System.out);

Which prints out:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:SubmitRequestDocResponse xmlns:ns2="http://tripauthority.com/hotel">
    <ns2:SubmitRequestDocResult>
        <!-- below is the object I'm trying to unmarshall -->
        <ArnResponse>
            <Info />
            <Availability>
                <!-- etc--> 
             </Availability>
        </ArnResponse>
    </ns2:SubmitRequestDocResult>
</ns2:SubmitRequestDocResponse>

How can I turn the ElementNSImpl object I'm seeing into the ArnResponse object I know it represents?

Additionally, I'm running on AppEngine, where file access is restricted.

Thanks for any help

Update:

I've added the @XmlAnyElement(lax=true) annotation, like so:

  @XmlAccessorType(XmlAccessType.FIELD)
  @XmlType(name = "", propOrder = {
      "content"
  })
  @XmlSeeAlso(ArnResponse.class)
  public static class SubmitRequestDocResult {

    @XmlMixed
    @XmlAnyElement(lax = true)
    protected List<Object> content;

But it doesn't make any difference.

Is this something to do with the fact that the content is a List?

Here's the code where I'm trying to access the content after getting it back from the server:

List list = rootResponse.getSubmitRequestDocResult().getContent();

for (Object o : list) {
  ArnResponse response = (ArnResponse) o;
  System.out.println(response);
}

Which has the output:

Jan 31, 2012 10:04:14 AM com.districthp.core.server.ws.alliance.AllianceApi getRates SEVERE: com.sun.org.apache.xerces.internal.dom.ElementNSImpl cannot be cast to com.districthp.core.server.ws.alliance.response.ArnResponse

Answer:

axtavt's answer did the trick. This worked:

Object content = ((List)result.getContent()).get(0);
JAXBContext context = JAXBContext.newInstance(ArnResponse.class);
Unmarshaller um = context.createUnmarshaller();
ArnResponse response = (ArnResponse)um.unmarshal((Node)content);
System.out.println("response: " + response);

You can pass that object to Unmarshaller.unmarshal(Node), it should be able to unmarshal it.