#Produces/provider media type matching - jersey

Question

I am experimenting with api verioning and have a very peculiar requirement to work against. We are going to use content-negotiation i.e #Produces annotation for this and I want to a custom media type in a format like #Produces({"th/v1-v10+xml"}), where v1-v10 tells that this api will serve any request with Accept header of "th/v1+xml", "th/v2+xml" all the way to "th/v10+xml".
I know this is a bit strange, but the idea is that each drop we make in production will be a new version for the client, but not every service will be modified. So I want to annotate the service with a range so that I don’t have to duplicate it for every drop even if it’s not changed.
So what i want to find out is there any way I can intercept the login in Jersey while it matched the #Path and #Produces annotations? I know I can’t use regex to match media types.
.......
A bit more research tells me that the Jersey calls the MediaType.isCompatible(MediaType other) method to determine the compatibility between the requests accept header and the services provider media type.
Is may be able to leverage this a bit if I can create a custom MediaType and override the isCompatible method. Does Jersey allows such extension??
Any help is much appreciated.

Answer 1

You probabily should have to use a custom response mapper.
1.- Create a class implementing MessageBodyWriter in charge of writing the response
#Provider
public class MyResponseTypeMapper
implements MessageBodyWriter<MyResponseObjectType> {
#Override
public boolean isWriteable(final Class<?> type,final Type genericType,
final Annotation[] annotations,
final MediaType mediaType) {
... use one of the arguments (either the type, an annotation or the MediaType)
to guess if the object shoud be written with this class
}
#Override
public long getSize(final MyResponseObjectType myObjectTypeInstance,
final Class<?> type,final Type genericType,
final Annotation[] annotations,
final MediaType mediaType) {
// return the exact response length if you know it... -1 otherwise
return -1;
}
#Override
public void writeTo(final MyResponseObjectType myObjectTypeInstance,
final Class<?> type,final Type genericType,
final Annotation[] annotations,
final MediaType mediaType,
final MultivaluedMap<String,Object> httpHeaders,
final OutputStream entityStream) throws IOException, WebApplicationException {
... serialize / marshall the MyResponseObjectType instance using
whatever you like (jaxb, etC)
entityStream.write(serializedObj.getBytes());
}
}
2.- Register the Mappers in your app
public class MyRESTApp
extends Application {
#Override
public Set<Class<?>> getClasses() {
Set<Class<?>> s = new HashSet<Class<?>>();
s.add(MyResponseTypeMapper.class);
return s;
}
}
Jersey will scan all registered Mappers calling their isWriteable() method until one returns true... if so, this MessageBodyWriter instance will be used to serialize the content to the client