JAXB cannot unmarshall - jaxb

Question

I cannot unmarshall a generic Type, like this.
I do not like it solve with an adapter class.
Can someone help..
interface Car {
}
class Car1 implements Car {
}
class Car2 implements Car {
}
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType( name = "", propOrder = { "car1" } )
#XmlRootElement(name = "Element")
class Element{
#XMLELEMENT(type="Car1.class" name="Car")
private Car car1;
}

Answer 1

If the xml you try to unmarshall has different tag for describing car1 and car2, then it is possible by using #XmlElements annotation.
I am creating a small example below to show case it:
#XmlRootElement
public class SomeRoot {
#XmlElements({
#XmlElement(type = Car1.class, name = "car1"),
#XmlElement(type = Car2.class, name = "car2")
})
private List<Car> cars;
}
Then your interface:
public interface Car {
}
A base class with some common field:
#XmlAccessorType(XmlAccessType.FIELD)
public class BaseCar {
private String type;
}
And implementation for car1:
#XmlAccessorType(XmlAccessType.FIELD)
public class Car1 extends BaseCar implements Car {
private String car1SpecificField;
}
and car2:
#XmlAccessorType(XmlAccessType.FIELD)
public class Car2 extends BaseCar implements Car {
private String car2SpecificField;
}
This would unmarshal the xml below fine:
<someRoot>
<car1>
<type>some type</type>
<car1SpecificField>some value</car1SpecificField>
</car1>
<car2>
<type>other type</type>
<car2SpecificField>other value</car2SpecificField>
</car2>
</someRoot>
If your xml has the <car> instead of <car1> and <car2> you need to use an adapter or else jaxb doesn't know to which class to unmarshall.