JAXB unmarshal with declared type does not populate the resulting object with data

Question

I am trying to unmarshal a given XML:

<FHcomment>
 <TX>rewriting of file</TX>
 <tool_id>toolA</tool_id>
 <tool_vendor>Company</tool_vendor>
 <tool_version>1.7.36.0</tool_version>
</FHcomment>

The schema has already been compiled to JAXB classes, see here:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
 "tx",
 "toolId",
 "toolVendor",
 "toolVersion",
 "userName",
 "commonProperties",
 "extensions"
})
@XmlRootElement(name = "FHcomment")
public class FHcomment {

@XmlElement(name = "TX", required = true)
protected TX tx;
@XmlElement(name = "tool_id", required = true)
protected BaseName toolId;
@XmlElement(name = "tool_vendor", required = true)
protected BaseName toolVendor;
@XmlElement(name = "tool_version", required = true)
protected BaseVersion toolVersion;
@XmlElement(name = "user_name")
protected BaseName userName;
@XmlElement(name = "common_properties")
protected CommonPropertiesType commonProperties;
protected ExtensionsType extensions;
@XmlAnyAttribute
private Map<QName, String> otherAttributes = new HashMap<QName, String>();

.....
/*
 * GETTERS and SETTERS for the fields have been removed here
 */
.....
}

My code to unmarshal the XML is as follows:

JAXBContext jc = JAXBContext.newInstance(FHcomment.class);
String s = "<FHcomment>....</Fhcomment>";
Unmarshaller unmarshaller = jc.createUnmarshaller();
XMLInputFactory fac = XMLInputFactory.newFactory();
XMLStreamReader xsr = fac.createXMLStreamReader(new StringReader(s));
JAXBElement<FHcomment> foo = unmarshaller.unmarshal(xsr, FHcomment.class);
FHcomment val = foo.getValue();

Problem: The resulting FHcomment object does not contain the children elements of FHcomment. All are null which is not the desired result.

How can I tell JAXB to completely unmarshal the given XML into an object?

EDIT: After adding a ValidationHandler to the Unmsarshaller, I got closer to the problem:

unexpected element (uri:"", local:"TX"). Expected elements are <{htp://www.example.com/mdf/v4}tool_id>,<{htp://www.example.com/mdf/v4}TX>,<{htp://www.www.example.com/mdf/v4}common_properties>,<{htp://www.example.com/mdf/v4}tool_version>,<{htp://www.example.com/mdf/v4}extensions>,<{htp://www.www.example.com/mdf/v4}tool_vendor>,<{htp://www.www.example.com/mdf/v4}user_name>

unexpected element (uri:"", local:"tool_id"). Expected elements are....

It turns out JAXB does not like the fact that the provided XML does not contain namespace information.. So how do I tell the unmarshaller to ignore the namespaces?

EDIT2:

After some more research I could not find a way to trick JAXB into working without namespace verification. I used the tutorial at http://cooljavablogs.blogspot.de/2008/08/how-to-instruct-jaxb-to-ignore.html to circumvent my problem. Not a nice solution but the best at hand...

Solution

Your XML document does not match the namespace qualification that was defined in your mappings (see: http://blog.bdoughan.com/2010/08/jaxb-namespaces.html). You could leverage an XMLFilter to apply a namespace to your XML document during the unmarshal operation.

import org.xml.sax.*;
import org.xml.sax.helpers.XMLFilterImpl;

public class NamespaceFilter extends XMLFilterImpl {

    private static final String NAMESPACE = "htp://www.example.com/mdf/v4";

    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
        super.endElement(NAMESPACE, localName, qName);
    }

    @Override
    public void startElement(String uri, String localName, String qName,
            Attributes atts) throws SAXException {
        super.startElement(NAMESPACE, localName, qName, atts);
    }

}

Below is an example of how you would leverage the XMLFilter during an unmarshal.

    // Create the XMLFilter
    XMLFilter filter = new NamespaceFilter();

    // Set the parent XMLReader on the XMLFilter
    SAXParserFactory spf = SAXParserFactory.newInstance();
    SAXParser sp = spf.newSAXParser();
    XMLReader xr = sp.getXMLReader();
    filter.setParent(xr);

    // Set UnmarshallerHandler as ContentHandler on XMLFilter
    Unmarshaller unmarshaller = jc.createUnmarshaller();
    UnmarshallerHandler unmarshallerHandler = unmarshaller
            .getUnmarshallerHandler();
    filter.setContentHandler(unmarshallerHandler);

    // Parse the XML
    InputSource xml = new InputSource("input.xml");
    filter.parse(xml);
    Object result = unmarshallerHandler.getResult();

For More Information

• http://blog.bdoughan.com/2012/11/applying-namespace-during-jaxb-unmarshal.html

Comments

[Slacky]

Sadly the classes are generated and any modification will be lost after an update to the schema definitions.

[Balint Bako]

Then update the xml... You need make BaseName and TX xml-serializable too, by the way. If you use a custom class as a property in a JAXB class, that is a "complex type" in the XSD.