Another option that might work out of the box would be to use the jax-rs @Consumes
annotation e.g @Consumes({"application/vnd.aerogear.v101+json"}) on the service
endpoints.
So by making an abstract PushNotificationSenderEndpoint and and several
PushNotificationSenderEndpointV101, PushNotificationSenderEndpointV102 with the right
@Consumes annotation should work. I haven't tried it though
Tried out this option as well, seems to work, but to use it one must set the Content-Type
to “application/vnd.aerogear.v101+json” instead of the Accept header.