If not a straight blocking method, a fluent conversion method to type R
could be useful IMO:
R to(Function<? super CompletionStage<T>, R> converter) {
return converter.apply(this);
}
This way, who needs a blocking get can have a function prepared with a
blocking operation:
<T> Function<CompletionStage<T>, T> blockingGet() {
cs -> {
Object[] result = { null, null };
CountDownLatch cdl = new CountDownLatch();
cs.whenComplete((v, e) -> {
if (e != null) {
result[1] = e;
} else {
result[0] = v;
}
cdl.countDown();
});
try {
cdl.await();
} catch (InterruptedException ex) {
throw new RuntimeException(ex);
}
if (result[1] != null) {
throw new RuntimeException(result[1]);
}
return result[0];
}
}
T t = cs.to(blockingGet());
while others can convert it to a more enabled dataflow system:
cs.to(Flux::fromFuture)
.filter(v -> v < 50)
.defaultIfEmpty(-10)
.subscribe(System.out::println, Throwable::printStackTrace);
2016-09-27 10:39 GMT+02:00 Viktor Klang <viktor.kl...@gmail.com>:
> Seems legit
>
> --
> Cheers,
> √
>
> On Sep 26, 2016 23:29, "Attila Szegedi" <szege...@gmail.com> wrote:
>
>> Not at all, you could just have a call to cancel() block until the future
>> completes.
>>
>> *ducks*
>>
>> Attila.
>>
>> > On 25 Sep 2016, at 16:34, Viktor Klang <viktor.kl...@gmail.com> wrote:
>> >
>> > If that truely is the case then the only way of implementing a readonly
>> > Future is by throwing an exception from cancel...
>> >
>> > --
>> > Cheers,
>> > √
>> >
>> > On Sep 25, 2016 4:20 PM, "Joe Bowbeer" <joe.bowb...@gmail.com> wrote:
>> >
>> >> This statement regarding what happens after cancel is called is
>> correct:
>> >>
>> >> "*After this method returns, subsequent calls to **isDone**() will
>> always
>> >> return true*. Subsequent calls to isCancelled() will always return true
>> >> if this method returned true."
>> >>
>> >> After cancel returns, the future is completed, hence isDone. If cancel
>> >> returns true, i.e. it was cancelled, then isCancelled returns true.
>> But,
>> >> for example if the future is already completed when cancel is called,
>> then
>> >> cancel will return false and isCancelled will return false.
>> >>
>> >> On Sep 25, 2016 6:49 AM, "David Holmes" <davidchol...@aapt.net.au>
>> wrote:
>> >>
>> >>> I think that was meant to read “After this method returns _*true*_,
>> >>> subsequent calls …”
>> >>>
>> >>>
>> >>>
>> >>> David
>>
>
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>
>
--
Best regards,
David Karnok
