JAXB Annotated Classes for JSON (Jackson) containing abstract property - json

Question

With the following classes, which make up the JSON message structure I transfer to the client side after a JAX-RS call (CXF), I receive
org.apache.cxf.jaxrs.client.ClientWebApplicationException: .Problem with reading the response message, class : class bg.vivacom.sel.dto.SELResponse, ContentType : application/json.
...
Caused by: org.codehaus.jackson.map.JsonMappingException: Can not construct instance of bg.vivacom.sel.dto.SELDTO, problem: abstract types can only be instantiated with additional type information
at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream#16edbe39; line: 1, column: 157] (through reference chain: bg.vivacom.sel.dto.SELResponse["dto"])
The returned object contains property dto which is an interface
#XmlRootElement(name = "SELResponse")
public class SELResponse implements Serializable{
#XmlElement(name = "corelationID")
private String corelationID;
#XmlElement(name = "responseTimeStamp")
private String responseTimeStamp;
#XmlElement(name = "respStatusCode")
private String respStatusCode;
#XmlElement(name = "respStatusMessage")
private String respStatusMessage;
#XmlElement(name = "processStatus")
private ProcessStatus processStatus;
#XmlElement(name = "dto")
private SELDTO dto;
The interface
public interface SELDTO extends Serializable {
is a way to include a number of different DTOs in my answer depending on the request, such as
#XmlRootElement(name = "customerProfile")
public class CustomerProfileDTO implements SELDTO {
#XmlElement(name = "customerCode")
private String customerCode;
...
and
#XmlRootElement(name = "sms")
public class SmsDTO implements SELDTO {
#XmlElement(name = "From")
private String from;
...
Any ideas how else I have to annotate the classes so that the response can be correctly set to the specific object type. I understand that it requires additional information as at the time it re-creates the dto object it doesn't know its type so I have tried to annotate the interface as follows:
#XmlSeeAlso({CustomerProfileDTO.class, SmsDTO .class})
public interface SELDTO extends Serializable {
but I still get the issue. Any thoughts would be appreciated it.

Answer 1

I would recommend using Jackson annotation '#JsonTypeInfo' for this case.
But if you must use JAXB annotations, use #XmlElements or #XmlElementRefs similar to how you'd use them with JAXB/XML:
#XmlElements({
#XmlElement(type=SubClass1.class, name="sub1"),
#XmlElement(type=SubClass2.class, name="sub2")
})
note that you must include specific mapping to possible subtypes here.