MOXy: inheritance and lists

Question

I'm using MOXy 2.5.1 along with Jersey 2.4 and Hibernate. I'm seeing a strange marshalling behavior with MOXy with a specific set of classes.

I have classes that look similar to this (with additional stuff removed for brevity):

public abstract class ListWrapper<M> {
    protected List<M> records = new ArrayList<M>();
    public abstract List<M> getRecords();
    // plus functions to make it look like a List / Iterator
}

public abstract class RecordList<T extends Record> extends ListWrapper<T> {
    protected Person person;
    @XmlElement
    public Person getPerson() { return person; }
}

public class FooList extends RecordList<Foo> {
    @Override
    @XmlElement(type=Foo.class)
    public List<Foo> getRecords() { return super.records; }
}

public class Holder {
    @XmlElement
    public FooList getFooList() { /* ... */ }
}

When Holder gets marshalled to XML using MOXy I get the following:

<holder>
    <fooList>
        <records>...</records>
        <records>...</records>
        <person>...</person>
    </fooList>
</holder>

I was expecting those <records> elements to be named <foos> instead.

If I put a name="foos" entry on the @XmlElement declaration in FooList I will get my expected name, but then MOXy does something else that's a bit strange. It will still output elements named <records> within the <fooList> element, but these <records> will only contain the <id> values for the (Hibernate) database entries that these correspond to. And so it looks like this:

<holder>
    <fooList>
        <records><id>5</id></records>
        <records><id>10</id></records>
        <person>...</person>
        <foos>...</foos>
        <foos>...</foos>
    </fooList>
</holder>

It doesn't matter if I use an @XmlElementWrapper, a @XmlJavaTypeAdapter, or any other thing I can think of. I will either get the wrong names, or a second set of elements that contain a limited set of data. It's almost as though MOXy is not understanding the inheritance structure here or something.

I'll play around with a few other things in the meantime (e.g. ListWrapper API; it's not my design), but to me this looks like a bug in MOXy. Note that the same behaviors happen with JSON, so this isn't limited to XML.

Answer 1

I found a solution. I simply put @XmlAccessorType(XmlAccessType.NONE) on the ListWrapper and RecordList classes (it was already on the FooList class in my code). I think MOXy is (incorrectly?) looking up the tree to ListWrapper and creating an output entry based on that.