37.2. Sharing an interface between client and server

It is usually possible to share an interface between the client and server. In the previous scenario, your JAX-RS services must implement an annotated interface, then reuse that same interface to create client proxies to invoke on the client side. However, this is limited when your JAX-RS methods return a Response object. This is problematic because, in a raw Response return type declaration, the client has no type information. There are two ways to work around this problem. The first is to use the @ClientResponseType annotation.

import org.jboss.resteasy.annotations.ClientResponseType;
import javax.ws.rs.core.Response;

@Path("/")
public interface MyInterface {

   @GET
   @ClientResponseType(String.class)
   @Produces("text/plain")
   public Response get();
}

This will not always work, because some MessageBodyReaders and MessageBodyWriters need generic type information in order to match and service a request.

@Path("/")
public interface MyInterface {

   @GET
   @Produces("application/xml")
   public Response getMyListOfJAXBObjects();
}

In this case, your client code can cast the returned Response object to a ClientResponse and use one of the typed getEntity() methods.

MyInterface proxy = ProxyFactory.create(MyInterface.class, "http://localhost:8081");
ClientResponse response = (ClientResponse)proxy.getMyListOfJAXBObjects();
List<MyJaxbClass> list = response.getEntity(new GenericType<List<MyJaxbClass>>());