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

From: Marek Potociar <>
Date: Fri, 28 Sep 2012 11:18:19 -0700

On Sep 27, 2012, at 7:30 AM, Sergey Beryozkin <> wrote:

> On 27/09/12 13:56, Sergey Beryozkin wrote:
>> Hi,
>> I can see AsyncResponse.resume throws IllegalStateException if the
>> invocation has not been suspended.
>> IMHO it is too much of a restriction, possibly an implementation
>> specific one.
>> IMHO, the following should work
>> @GET
>> void getIt(AsyncResponse response) {
>> response.resume(myObject);
>> }
>> 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.
> Here is some more reasoning about it.
> AsyncResponse does not let users explicitly initiate suspend() but warns them they can 'hit' IllegalStateException.
> It is really the responsibility of the runtime to make sure the invocation can be properly suspended - but not at the cost of preventing the user from reacting to AsyncResponse immediately.
> The other thing is that AsyncResponse should be able to accept 'null' resumes, example, 204 in return to GET should work too - this makes it difficult to use AsyncResponse.resume for the immediate provision of the response.
> Thus I'd like to do a minor improvement:
> - add AsyncResponse.accept(Object)
> - make AsyncResponse.resume(Object) throw ISE if it is called in scope of method like getIt(), and make accept either throw ISE or let the runtime delegate to resume() if called outside of getIt().
> That will make it unambiguous but will also let implementations do whatever they want with respect to managing AsyncResponse, example, fork a thread and suspend the invocation even before getIt is invoked or
> suspend only after getIt returns and no accept has been called
> Does it make sense ?

What is the difference between accept and resume? To me it's the same and accept() is just a redundant method. Your implementation knows the context in which the resume() is invoked. You can make the necessary optimizations internally in your impl. Users do not need to be bothered by that and can just use the single resume method.

> Sergey