CompletableFuture already completed with an exception

Question

CompletableFuture.completedFuture() returns a CompletedFuture that is already completed with the given value.

How do we construct a CompletableFuture that is already completed exceptionally?

Meaning, instead of returning a value I want the future to throw an exception.

Answer 1

I just found this:

CompletableFuture<T> future = new CompletableFuture<>();
future.completeExceptionally(t);

There is no static factory method, but the default constructor seems to do the job.

Answer 2

Java 9 provides CompletableFuture.failedFuture​(Throwable ex) that does exactly that.