Is there an out-of-the-box thread pool with multiple queues (that ensure serial processing of each queue)?

Question

Among all my tasks, I have some that must be processed serially (they can never run concurrently and they must be processed in order).

I achieved that creating a sep

Answer 1

A single thread executor will do

ExecutorService  executorService = Executors.newSingleThreadExecutor();

Which internally uses a ThreadPoolExecutor with a LinkedBlockingQueue

new ThreadPoolExecutor(1, 1,0L, TimeUnit.MILLISECONDS,
                                new LinkedBlockingQueue()))

So you can use this for your sequential stuff and probably use a multi-threaded executor service for concurrent tasks