JAXB Annotations - Mapping interfaces and @XmlElementWrapper

I am having trouble with JAXB annotations for a field that is a list whose generified type is an interface. When I have it declared such as: ``` @XmlAnyElement private List<Animal> animals; ``` Every thing works correctly. But when I add a wrapper element, such as: ``` @XmlElementWrapper @XmlAnyElement private List<Animal> animals; ``` I find that the Java object marshals correctly, but when I unmarshal the document created by marshaling, my list is empty. I have posted below the code to demonstrate this problem. Am I doing something wrong, or is this a bug? I have tried it with version 2.1.12 and 2.2-ea with the same result. I am working through the example for mapping interfaces with annotations located here: https://jaxb.dev.java.net/guide/Mapping_interfaces.html ``` @XmlRootElement class Zoo { @XmlElementWrapper @XmlAnyElement(lax = true) private List<Animal> animals; public static void main(String[] args) throws Exception { Zoo zoo = new Zoo(); zoo.animals = new ArrayList<Animal>(); zoo.animals.add(new Dog()); zoo.animals.add(new Cat()); JAXBContext jc = JAXBContext.newInstance(Zoo.class, Dog.class, Cat.class); Marshaller marshaller = jc.createMarshaller(); ByteArrayOutputStream os = new ByteArrayOutputStream(); marshaller.marshal(zoo, os); System.out.println(os.toString()); Unmarshaller unmarshaller = jc.createUnmarshaller(); Zoo unmarshalledZoo = (Zoo) unmarshaller.unmarshal(new ByteArrayInputStream(os.toByteArray())); if (unmarshalledZoo.animals == null) { System.out.println("animals was null"); } else if (unmarshalledZoo.animals.size() == 2) { System.out.println("it worked"); } else { System.out.println("failed!"); } } public interface Animal {} @XmlRootElement public static class Dog implements Animal {} @XmlRootElement public static class Cat implements Animal {} } ```