How to implement CompletableFuture.allOf() that completes exceptionally once any of the futures fail?

Question

I want to implement a hybrid of CompletableFuture.allOf() and CompletableFuture.anyOf() where the returned future completes successfully as soon as

Answer 1

This question is actually very similar to Replace Futures.successfulAsList with Java 8 CompletableFuture?

Although the question is not exactly the same, the same answer (from myself) should satisfy your needs.

You can implement this with a combination of allOf() and chaining each input future with an exceptionally() that would make the future returned by allOf() immediately fail:

CompletableFuture a = …, b = …, c = …;
CompletableFuture allWithFailFast = CompletableFuture.allOf(a, b, c);
Stream.of(a, b, c)
    .forEach(f -> f.exceptionally(e -> {
        allWithFailFast.completeExceptionally(e);
        return null;
    }));