CompletableFutureVoid

CompletableFutureVoid is a conceptual type used in some Java codebases to represent an asynchronous computation that completes without producing a value. It serves as a specialization of the broader asynchronous model provided by CompletableFuture, emphasizing tasks whose outcome is the completion event rather than a returned result.

In practice, CompletableFutureVoid is typically implemented as a wrapper around a standard CompletableFuture<Void> or as a type alias in languages or libraries that support such aliases. The goal is to improve readability and express intent, signaling to callers that the task’s result is not meaningful and that only completion status, success, or failure matters.

Semantics and API aspects focus on completion without a value. Operations available on CompletableFutureVoid mirror those of CompletableFuture in terms of chaining and exception handling, but the value-producing forms are either absent or adapted. For example, continuations that do not take a result (such as a runnable action) are common, while those that consume a non-existent value are typically replaced with thenRun or whenComplete to observe completion and possible exceptions. A join or get operation returns a Void value (often null) consistent with the underlying Void type.

Usage patterns include background tasks, non-returning asynchronous operations, and event-notification workflows where the important aspect is that the task completes successfully or with an error, not any data produced. Benefits include clearer intent and potential API ergonomics; drawbacks include potential ambiguity with the generic Void type and the added abstraction layer.

See also: CompletableFuture, CompletionStage, Void.