JAXB: How should I marshal complex nested data structures?

Question

I have several complex data structures like

Map< A, Set< B > >
Set< Map< A, B > >
Set< Map< A, Set< B > > >
Map<         


        

Answer 1

Here is my marshaller/unmarshaller for the list of @XmlType class.

E.g

//Type to marshall
@XmlType(name = "TimecardForm", propOrder = {
"trackId",
"formId"
}) 
public class TimecardForm {

    protected long trackId;
    protected long formId;
    ...
}

//a list holder
@XmlRootElement
public class ListHodler {
    @XmlElement
    private List value ;

    public ListHodler() {
    }

    public ListHodler(List value) {
        this.value = value;
    }

    public List getValue() {
        if(value == null)
            value = new ArrayList();
        return this.value;
    }
}

//marshall collection of T
public static  void marshallXmlTypeCollection(List value,
        Class clzz, OutputStream os) {
    try {
        ListHodler holder = new ListHodler(value);
        JAXBContext context = JAXBContext.newInstance(clzz,
                ListHodler.class);
        Marshaller m = context.createMarshaller();
        m.setProperty("jaxb.formatted.output", true);

        m.marshal(holder, os);
    } catch (JAXBException e) {
        e.printStackTrace();
    }
}

//unmarshall collection of T
@SuppressWarnings("unchecked")
public static  List unmarshallXmlTypeCollection(Class clzz,
        InputStream input) {
    try {
        JAXBContext context = JAXBContext.newInstance(ListHodler.class, clzz);
        Unmarshaller u = context.createUnmarshaller();

        ListHodler holder = (ListHodler) u.unmarshal(new StreamSource(input));

        return holder.getValue();
    } catch (JAXBException e) {
        e.printStackTrace();
    }

    return null;
}