An invocation of the resource method throws WebApplicationException. Though javadoc does not state that in an invoke method, with respect to other javadoc occurences (such as submit), the GenericType<Response> should not throw an exception, because the status code is included in the response. Similarily to invoke(Response.class) which does not throw the exception either.
javadoc for Invocation#submit says:
Note that calling the Future.get() method on the returned Future instance may throw an ExecutionException that wraps either an ClientException thrown in case of an invocation processing failure or a WebApplicationException or one of its subclasses thrown in case the received response status code is not successful and the specified response type is not Response.
does not work either.