The following snippet is a method of a Junit 4 test with a green light:
@Test
public void testUnmarshallFromParentToChild() throws JAXBException {
Person person = new Person();
int age = 30;
String name = "Foo";
person.name = name;
person.age= age;
// Marshalling
JAXBContext context = JAXBContext.newInstance(person.getClass());
Marshaller marshaller = context.createMarshaller();
StringWriter writer = new StringWriter();
marshaller.marshal(person, writer);
String outString = writer.toString();
assertTrue(outString.contains("</person"));
// Unmarshalling
context = JAXBContext.newInstance(Person.class, RecieverPerson.class);
Unmarshaller unmarshaller = context.createUnmarshaller();
StringReader reader = new StringReader(outString);
RecieverPerson reciever = (RecieverPerson)unmarshaller.unmarshal(reader);
assertEquals(name, reciever.name);
assertEquals(age, reciever.age);
}
The important part is the use of the JAXBContext.newInstance(Class... classesToBeBound)
method for the unmarshalling context:
context = JAXBContext.newInstance(Person.class, RecieverPerson.class);
With this call, JAXB will compute a reference closure on the classes specified and will recognize RecieverPerson
. The test passes. And if you change the parameters order, you’ll get a java.lang.ClassCastException
(so they must be passed in this order).