Marshalling a List of objects implementing a common interface, with JaxB

Question

I am trying to marshall a list of objects implementing a common interface. There are 3 classes and 1 interface involved:

Community class (has one method: List<Person> getPeople();)

Person interface (has one method: String getName();)

Girl class (implements Person)

Boy class (implements Person)

See code below.

I want an XML that looks something like this:

<community>   <people>     <girl>       <name>Jane</name>     </girl>     <boy>       <name>John</name>     </boy>     <girl>       <name>Jane</name>     </girl>     <boy>       <name>John</name>     </boy>   </people> </community> 

or possibly:

<community>   <people>    <person>       <girl>         <name>Jane</name>       </girl>     </person>     <person>       <boy>         <name>John</name>       </boy>     </person>   </people> </community> 

So far what I get is this:

<community>     <people>         <person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="girl">             <name>Jane</name>         </person>         <person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="boy">             <name>John</name>         </person>         <person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="girl">             <name>Jane</name>         </person>         <person xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="boy">             <name>John</name>         </person>     </people> </community> 

I realize I can change the element to something else, but I want the element name to be the name spesified in the Girl or Boy class.

Can this be done? Thanks.

@XmlRootElement(name = "community") public class Community {   private List<Person> people;   @XmlElementWrapper  @XmlElement(name="person")  public List<Person> getPeople() {   return people;  }   public Community() {   people = new ArrayList<Person>();   people.add(new Girl());   people.add(new Boy());   people.add(new Girl());   people.add(new Boy());  } }        @XmlRootElement(name = "girl") public class Girl implements Person {   @XmlElement  public String getName() {   return "Jane";  } }   @XmlRootElement(name = "boy") public class Boy implements Person {   @XmlElement  public String getName() {   return "John";  } }    @XmlJavaTypeAdapter(AnyTypeAdapter.class) public interface Person {  public String getName(); }    public class AnyTypeAdapter extends XmlAdapter<Object, Object> {   @Override    public Object marshal(Object v) throws Exception {     return v;    }   @Override    public Object unmarshal(Object v) throws Exception {     return v;    }  } 

Answer 1

For this scenario I would recommend the use of @XmlElements. @XmlElements is used to represent the XML schema concept of choice:

• http://bdoughan.blogspot.com/2010/10/jaxb-and-xsd-choice-xmlelements.html

Here is how it would look for your example:

@XmlElements({      @XmlElement(name="girl", type=Girl.class),     @XmlElement(name="boy", type=Boy.class) }) @XmlElementWrapper public List<Person> getPeople() {     return people; } 

@XmlElementRef corresponds to the concept of substitution groups in XML schema. This is why the previous answer requires Person to be changed from an interface to a class.

• http://bdoughan.blogspot.com/2010/11/jaxb-and-inheritance-using-substitution.html