What advantage is there to using Spring @Async vs. CompleteableFuture directly?

What’s the advantage of using Spring Async vs. Just returning the CompletableFuture on your own?

Answer

Your application is managed by the container. Since it’s discouraged to spawn Threads on you own, you can let the container inject a managed Executor.

@Service
class MyService {
  @Autowired
  private Executor executor;

  public CompletableFuture<?> compute() {
    return CompletableFuture.supplyAsync(() -> /* compute value */, executor);
  }
}