What you can do is create a MessageBodyReader/Writer that handles the 2.x version of Jackson. The isReadable and isWritable methods determine which entities it can handle. What you can do to check is inject Jersey's ExtendedUriInfo into the provider and check the resource class for your @Jackson2 annotation. If the annotation is not present than your provider ignores the entity and the runtime moves on to the next provider and checks if it can handle it; in this case the 1.x provider.
Instead of completely creating your own, you would just extend the provider that Jackson already provides in it artifact
<dependency>
<groupId>com.fasterxml.jackson.jaxrs</groupId>
<artifactId>jackson-jaxrs-json-provider</artifactId>
<version>2.9.2</version>
</dependency>
You would extend the JacksonJaxbJsonProvider.
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface Jackson2 {
}
@Provider
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class MyProvider extends JacksonJaxbJsonProvider {
@Context
private ExtendedUriInfo info;
@Override
public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
if (!info.getMatchedMethod().getDeclaringResource().isAnnotationPresent(Jackson2.class)) {
return false;
}
return super.isReadable(type, genericType, annotations, mediaType);
}
@Override
public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
if (!info.getMatchedMethod().getDeclaringResource().isAnnotationPresent(Jackson2.class)) {
return false;
}
return super.isWriteable(type, genericType, annotations, mediaType);
}
}
Then just annotate your resource classes with @Jackson2.
I had problems earlier while trying to get this to work, because I was using Jackson 2.8.4. It seams the whole 2.8 line has a problem. Not sure what it is, but with 2.8, my provider would not register at all. I tested with minor versions 2.2-2.9 (excluding 2.8) and they all work.
As far as priority, I'm not sure about how Jersey determines precedence. If the 1.x provider were to be called first, then this solution would all fall apart. One way around this would be to use composition instead of inheritance, where you would Just determine which reader/writer (1.x or 2.x) to use inside your readFrom and writeTo methods. The 1.x version is also JacksonJaxbJsonProvider but it used the codehaus packaging. From what I tested though, my provider always gets called first, so this may not be needed. Unfortunately, I cannot confirm that this is by design.
