title: Force re-use of thread by CompletableFuture
body: <p>I am making critical use of:</p>
  
  <pre><code> CompletableFuture
    .delayedExecutor(1, TimeUnit.MILLISECONDS).execute(() -&gt; {});
  </code></pre>
  
  <p>From what I have read online, it's common for this to use a new thread for every call. I am wondering if there is a way to re-use a thread instead of creating new threads? </p>
  
  <p><strong>Update</strong>:</p>
  
  <p>I wasn't clear - I want to use <code>CompletableFuture</code>, but I want <code>CompletableFuture</code> to reuse a certain thread, instead of managing its own threads.</p>
  
  <p>I see this question:
  <a href="https://stackoverflow.com/questions/39165655/completablefuture-reuse-thread-from-pool/39166632">CompletableFuture reuse thread from pool</a></p>
  
  <p>but it recommends using an environment variable - I am wondering if there is a way to do this programmatically.</p>