[jax-rs-spec users] [jsr339-experts] Re: AsyncResponse should be able to accept responses immediately

From: Marek Potociar <>
Date: Fri, 28 Sep 2012 11:15:21 -0700

On Sep 27, 2012, at 5:56 AM, Sergey Beryozkin <> wrote:

> Hi,
> I can see AsyncResponse.resume throws IllegalStateException if the invocation has not been suspended.

I was thinking of updating the API earlier to return boolean success value instead of throwing exceptions from resume/cancel methods and forgot to make the change. That's more user-friendly than throwing an exception.
> IMHO it is too much of a restriction, possibly an implementation specific one.

When you inject the AsyncResponse it is formally suspended. So the first invocation of resume() is always ok (unless the async response has been cancelled already).
 The exception thus may only be expected in cases when someone else already resumed or cancelled the response earlier. I don't see anything implementation specific about that. I could however agree that returning boolean instead of throwing an exception may be more user-friendly.
> IMHO, the following should work
> @GET
> void getIt(AsyncResponse response) {
> response.resume(myObject);
> }

IMHO, the above should not work, unless you use @Suspended annotation. Because since JAX-RS 1.0, the first non-anotated parameter in a resource method is a request entity. AsyncResponse is not a request entity.

If one uses the @Suspended annotation, then the example should work. Because, at least formally, the AsyncResponse has been suspended. What optimizations you do in your implementation is, of course up, to you.

> if 'myObject' happens to be available immediately.
> The runtime has to suspend only after "getIt" returns, but only if no response object is already available.

Now this is an implementation detail IMO. :)


> Thoughts ?
> Sergey