From: Yangyang Liu <yyliu28_at_gmail.com>
Date: Sat, 12 May 2012 21:53:38 -0700

Hi All,

I am a newbie to Rest framework and Jersey. I got a question about
injecting a resource into a list of abstract class in Jersey Rest. I had
goolged around but didn't find a workaround for it.

I have the following abstract class:

@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME,
    include = JsonTypeInfo.As.PROPERTY,
    property = "segment_type")
@JsonSubTypes({
@Type(value = SimpleSegment.class, name = "simple_segment")})
*public abstract class Segment** *
{
    public abstract String getName();
    public abstract String getValue(Map<String, String> attributeMap);
}

The SimpleSegment class is an implementation of Segment:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement
*public class SimpleSegment extends Segment*
{
    @JsonProperty
    private String value;

    // constructor and getters follow.
}

The following is the public interface for posting a list of segment instances:

@Component
@Consumes({ ContentType.CONTENT_TYPE_XML, ContentType.CONTENT_TYPE_JSON })
@Path("/create_segment_list")
@Produces({ ContentType.CONTENT_TYPE_XML, ContentType.CONTENT_TYPE_JSON })
@Scope("singleton")
*public class CreateSegmentListResource** *
{
    private xxxManager manager;

    @Autowired
    public CreateSegmentListResource(final xxxManager manager)
    { this.manager = manager;}

    @POST
    public Response createAccountingTreatment(
        @RequestBody final CreateSegmentListRequest creationRequest,
        @Context final HttpHeaders httpHeaders,
        @Context final UriInfo uriInfo)
    {
        System.out.println("Yeah, we will create the segment list!!!");

        if (creationRequest == null)
        {
            System.out.println("it's null!!");
        }
        else
        {
            System.out.println("no, it's not null!");
            System.out.println("things: " + creationRequest.getList());
        }

        return Response.status(Status.OK).build();
    }
}

The CreateSegmentListRequest is as follows:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement
*public class CreateSegmentListRequest** *
{
    @JsonProperty
    private List<*Segment*> list;

    @SuppressWarnings("unused")
    private CreateSegmentListRequest() { }

    public CreateSegmentListRequest(final List<Segment> list)
    {
        this.list = list;
    }

    public List<Segment> getList()
    {
        return list;
    }
}

If I send a post query to the above resource by attaching a json
string of a list of SimpleSegment instances, I get the following
error:

"The request sent by the client was syntactically incorrect (Bad Request)."

However, if the list in CreateSegmentListRequest is changed to a list of
SimpleSegment, then there is no error and the CreateSegmentListRequest can
be correctly constructed in the resource class.

Anyone knows of a workaround for my problem? Obviously I don't want to have
a separate CreateSegmentListRequest for each implementation of Segment
class.


Regards,

Yangyang