[jax-rs-spec users] Re: Suggestion to refactor rx invoker API

From: Sergey Beryozkin <>
Date: Sun, 15 Jan 2017 16:20:41 +0000

IMHO rx() needs to remain in order to get the default, this is as simple
as it can get. Doing more than rx() in order to get CompletionStage
would be bad.

But I'm warming to something similar to what you are suggesting.
.unwrap() is redundant IMHO.

either rx() for the default

or, example,

RxInvoker<Observable> rxInvoker = rx(Observable.class)

The reason it works better than the prototype suggested by Pavel is that
this code is *portable*.

Clearly, in most cases, it won't be the users who will create
RxInvoker<Observable>, etc but Jersey, CXF, RestEasy will have dedicated
modules with META-INF linking, in this case, Observable to a specific
RxInvoker. This will be documented and users willing to work with
non-default rx() will add a given module to the classpath...


On 14/01/17 14:28, Markus KARG wrote:
> Sounds good for me, but actually I think it would be even simpler if
> we name it "unwrap()", and do not fill in any parameters. As I said, I
> think applications will typically use only one technology at the time.
> So "unwrap()" simply can check if there is a @Provider registered
> having a method with the same parameters as your proposed "conver()",
> we finally have the requested plugability, no additonal complexity,
> follow existing JAX-RS patterns, and get rid of repeating lots of
> "rx(Class)". :-)
> -Markus
> *From:*Ondrej Mihályi []
> *Sent:* Samstag, 14. Januar 2017 12:54
> *To:*
> *Subject:* Suggestion to refactor rx invoker API
> I was thinking about an alternative to current rx API, to simplify it
> in context of supporting extensibility.
> My idea is to modify the CompletionStageRxInvoker, so that it returns
> an extension to CompletionStage, which would contain additional method
> to convert the interface to any other reactive interface:
> public interface RxCompletionStage<T> extends CompletionStage<T> {
> <NEW> NEW convert(Function<CompletionStage<T>, NEW> converter);
> }
> With this, we would move all the complexity to this new interface,
> which still can be used as a usual CompletionStage, but with the
> additional convert method, it provides an extension point to other
> interfaces. And it's based on standard CompletionStage, therefore we
> don't need additional rx invokers.
> We could remove RxInvokerProvider, the 2 rx() methods from the
> Builder, which accept RxInvokerProvider, and even remove the RxInvoker
> interface, as CompletionStageRxInvoker would be the only required
> implementation.
> Here is an example of what I mean, with RxJava2 as an example:
> *client*.request().rx().get(). // we get the RxCompletionStage here,
> which extends CompletionStage .convert(this::flowableFromStage)
> // accepts a function that converts the CompletionStage to another
> interface .subscribe(s -> testResult = s, Throwable::printStackTrace);
> An example of a working code here
> <>
> (although not using JAX-RS, just wrapping a method that returns a
> CompletionStage).
> Ondrej