[Resteasy-developers] Unable to fetch StreamingOutput via Client Api

[Gregor J. <gr...@ja...>]

Hi,

I have to proxy a request from one Jax-RS resource to another (secured) one.

RestInterface {

    @GET
    @Path("/{id}")
    @Produces({"image/jpeg"})
    public StreamingOutput getImage(@PathParam("id") String id);

}

RestProxyInterface {

    @GET
    @Path("/{id}")
    @Produces({"image/jpeg"})
    public StreamingOutput getImage(@PathParam("id") String id){
        // create client proxy ... --> remoteRestInterface  
        StreamingOutput image = remoteRestInterface.getImage(id);
        return image;
    }
}

Client api causes following exception: 
Caused by: javax.ws.rs.ProcessingException: Unable to find a MessageBodyReader of content-type image/jpeg and type interface javax.ws.rs.core.StreamingOutput
	at org.jboss.resteasy.core.interception.ClientReaderInterceptorContext.throwReaderNotFound(ClientReaderInterceptorContext.java:39)
	at org.jboss.resteasy.core.interception.AbstractReaderInterceptorContext.getReader(AbstractReaderInterceptorContext.java:73)
	at org.jboss.resteasy.core.interception.AbstractReaderInterceptorContext.proceed(AbstractReaderInterceptorContext.java:50)
	at org.jboss.resteasy.plugins.interceptors.encoding.GZIPDecodingInterceptor.aroundReadFrom(GZIPDecodingInterceptor.java:59)
	at org.jboss.resteasy.core.interception.AbstractReaderInterceptorContext.proceed(AbstractReaderInterceptorContext.java:53)
	at org.jboss.resteasy.client.jaxrs.internal.ClientResponse.readFrom(ClientResponse.java:244)
	at org.jboss.resteasy.client.jaxrs.internal.ClientResponse.readEntity(ClientResponse.java:178)
	at org.jboss.resteasy.specimpl.BuiltResponse.readEntity(BuiltResponse.java:211)
	at org.jboss.resteasy.client.jaxrs.internal.ClientInvocation.extractResult(ClientInvocation.java:104)
	... 35 more

So, obviously there is no reader for StreamingOutput.
Creating on: 

@Provider
@Consumes("image/jpeg")
public class StreamingOutputReader implements MessageBodyReader<StreamingOutput> {
    @Override
    public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return StreamingOutput.class.isAssignableFrom(type);
    }

    @Override
    public StreamingOutput readFrom(Class<StreamingOutput> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, String> httpHeaders, final InputStream entityStream) throws IOException, WebApplicationException {
        return new StreamingOutput() {
            @Override
            public void write(OutputStream output) throws IOException, WebApplicationException {
                byte[] buffer = new byte[1024];
                int bytesRead;
                while ((bytesRead = entityStream.read(buffer)) != -1) {
                    output.write(buffer, 0, bytesRead);
                }
            }
        };
    }
} 

Unfortunately I cannot get it to be invoked by the Client Api. Scanning providers is on and according to the logs it is recognized by resteasy.. Debugging through the code, indeed the providerFactory of ClientReaderInterceptorContext doesn't have my StreamingOutputReader...

What am I doing wrong here?

Thanks,

Gregor