when does JAXB unmarshaller.unmarshal returns a JAXBElement or a MySchemaObject?

Question

I have two codes, in two different java projects, doing almost the same thing, (unmarshalling the input of a webservice according to an xsd-file).

But in one case I

Answer 1

Thanks to all your explanations and links, I've have written this so as to take care of both cases, using Annotation Introspection.

This has the advantage of:

• not modifying generated java classes
• allowing all possible xsd format

It works for output as well as input, and is according to me more generic:

public class JaxbWrapper {

    private static boolean isXmlRootElement(Class classT){
        
        Annotation[] annotations = classT.getAnnotations();
        
        for(Annotation annotation : annotations){
            if(annotation instanceof XmlRootElement){
                return true;
            }
        }       
        
        return false;
    }
    
    public static Object unmarshall(Class classObjectFactory, Class classObject, XMLStreamReader xmlStreamReader){
        
        Package pack = classObjectFactory.getPackage();
        String strPackageName = pack.getName();
        
        Object returnObject = null;
        
        try {
            JAXBContext jc = JAXBContext.newInstance(strPackageName, classObjectFactory.getClassLoader());
            
            Unmarshaller unmarshaller = jc.createUnmarshaller();
            
            returnObject = unmarshaller.unmarshal( xmlStreamReader );
            
            boolean bIsRootedElement = isXmlRootElement(classObject);
            if(!bIsRootedElement)
            {
                JAXBElement jaxbElement = (JAXBElement) returnObject;
                returnObject = jaxbElement.getValue();              
            }
        }
        catch (JAXBException e) {
            /*...*/
        }   

        return returnObject;
    }
    
    private static void writeToXml(Class classObjectFactory, Object obj, XMLStreamWriter xmlStreamWriter){
        
        Package pack = classObjectFactory.getPackage();
        String strPackageName = pack.getName();
        
        try {       
            JAXBContext jc = JAXBContext.newInstance(strPackageName, classObjectFactory.getClassLoader());
            Marshaller marshaller = jc.createMarshaller();
            marshaller.marshal(obj, xmlStreamWriter);
        }
        catch(JAXBException e) {
            /*...*/
        }       
    }
    
    public static String marshall(Class classObjectFactory, Class classObject, Object obj){
        
        Object objectToMarshall = obj; 
        
        boolean bIsRootedElement = isXmlRootElement(classObject);
        if(!bIsRootedElement)
        {
            Package pack = classObjectFactory.getPackage();
            String strPackageName = pack.getName();
            
            String strClassName = classObject.getName();
            
            QName qName = new QName(strPackageName, strClassName);
            
            JAXBElement jaxbElement = new JAXBElement(qName, classObject, null, obj);
            
            objectToMarshall = jaxbElement; 
        }
        
        StringWriter sw = new StringWriter();
        XMLOutputFactory xmlOutputFactory = XMLOutputFactory.newInstance();
        XMLStreamWriter xmlStreamWriter = null;
        
        try {
            xmlStreamWriter = xmlOutputFactory.createXMLStreamWriter(sw);
            
            writeToXml(classObjectFactory, objectToMarshall, xmlStreamWriter);

            xmlStreamWriter.flush();
            xmlStreamWriter.close();
        } 
        catch (XMLStreamException e) {
            /*...*/
        }

        return sw.toString();
    }
}