Transform Java Future into a CompletableFuture

Question

Java 8 introduces CompletableFuture, a new implementation of Future that is composable (includes a bunch of thenXxx methods). I\'d like to use this exclusively,

Answer 1

Let me suggest another (hopefully, better) option: https://github.com/vsilaev/java-async-await/tree/master/com.farata.lang.async.examples/src/main/java/com/farata/concurrent

Briefly, the idea is the following:

1. Introduce CompletableTask interface -- the union of the CompletionStage + RunnableFuture
2. Warp ExecutorService to return CompletableTask from submit(...) methods (instead of Future)
3. Done, we have runnable AND composable Futures.

Implementation uses an alternative CompletionStage implementation (pay attention, CompletionStage rather than CompletableFuture):

Usage:

J8ExecutorService exec = J8Executors.newCachedThreadPool();
CompletionStage = exec
   .submit( someCallableA )
   .thenCombineAsync( exec.submit(someCallableB), (a, b) -> a + " " + b)
   .thenCombine( exec.submit(someCallableC), (ab, b) -> ab + " " + c);