Async Requests

Blocking on every HTTP call wastes threads. The JDK HTTP client offers sendAsync, which returns a CompletableFuture immediately and performs the work on a background executor.

This lets you fire many requests concurrently and compose their results without manually managing threads.

The signatures differ in what they return:

• send returns HttpResponse<T> and blocks, declaring IOException and InterruptedException.
• sendAsync returns CompletableFuture<HttpResponse<T>> and never blocks; errors surface through the future.