title: Why is there no scheduled cached thread pool provided by the Java Executors class?
body: <p><code>Executors</code> provides <code>newCachedThreadPool()</code> and <code>newScheduledThreadPool()</code>, but not <code>newCachedScheduledThreadPool()</code>, what gives here?  I have an application that receives bursty messages and needs to schedule a fairly lengthy processing step after a fixed delay for each.  The time constraints aren't super tight, but I would prefer to have more threads created on the fly if I exceed the pool size and then have them trimmed back during periods of inactivity.  Is there something I've missed in the concurrent library, or do I need to write my own?</p>