Unmarshalling XML using JAXB in restlet's acceptRepresentation method.

Question

I've created an XML schema by annotating an existing Java domain model class, now when I try to use JAXB to unmarshall the representation received within my restlet webservice I'm getting a host of errors no matter what I seem to try. I'm new to both restlets and JAXB so pointing me in the direction of a decent example of using both would be helpful only one I've managed to find so far was here: Example

My errors are:

If I try to use the restlet.ext.jaxb JaxbRepresentation:

@Override 
public void acceptRepresentation(Representation representation)
    throws ResourceException {
JaxbRepresentation<Order> jaxbRep = new JaxbRepresentation<Order>(representation, Order.class);
jaxbRep.setContextPath("com.package.service.domain");

Order order = null;

try {

    order = jaxbRep.getObject();

}catch (IOException e) {
    ...
}

from this I get a java.io.IOException: Unable to unmarshal the XML representation.Unable to locate unmarshaller. exception at jaxbRep.getObject()

So I also tried a different approach to see if that made a difference, using the following code instead:

@Override 
public void acceptRepresentation(Representation representation)
    throws ResourceException {

try{

    JAXBContext context = JAXBContext.newInstance(Order.class);

    Unmarshaller unmarshaller = context.createUnmarshaller();

    Order order = (Order) unmarshaller.unmarshal(representation.getStream());

} catch( UnmarshalException ue ) {
    ...
} catch( JAXBException je ) {
    ...
} catch( IOException ioe ) {
    ...
}

However this also gives me the following exception when call to JAXBContext.newInstance is made.

java.lang.NoClassDefFoundError: javax/xml/bind/annotation/AccessorOrder

Thanks in advance for any advice.

Answer 1

Seems there was a couple of errors here, I never had an ObjectFactory class and I was using out of date versions of the JAXB libraries, after adding this class and updating to 2.1.11 it seems to work now

Answer 2

The Jaxb Extension for Restlet didn't work for me too. I got the same Unable to marshal Exception along with some more Exceptions. Strangely the JAXBContext.newInstance() call itself worked fine in my code. Because of that, i wrote a simple JaxbRepresenetation class:

public class JaxbRepresentation extends XmlRepresentation {

private String contextPath;
private Object object;

public JaxbRepresentation(Object o) {
    super(MediaType.TEXT_XML);
    this.contextPath = o.getClass().getPackage().getName();
    this.object = o;
}

@Override
public Object evaluate(String expression, QName returnType) throws Exception {
    final XPath xpath = XPathFactory.newInstance().newXPath();
    xpath.setNamespaceContext(this);

    return xpath.evaluate(expression, object, returnType);

}

@Override
public void write(OutputStream outputStream) throws IOException {
    try {
        JAXBContext ctx = JAXBContext.newInstance(contextPath);
        Marshaller marshaller = ctx.createMarshaller();
        marshaller.marshal(object, outputStream);
    } catch (JAXBException e) {
        Context.getCurrentLogger().log(Level.WARNING, "JAXB marshalling error!", e);
        throw new IOException(e);
    }
}
}