Using ScheduledExecutorService method to run a batch of tasks periodically

Question

I want to submit a batch of tasks at once and also execute them periodically. Using ExecutorService object and invokeall method it's possible to run tasks at once. But trying to use scheduleAtFixedRate , it's not compatible:

executor.scheduleAtFixedRate(executor.invokeAll(callables), initialDelay, period, TimeUnit.SECONDS );

How can I execute a batch of tasks at once and periodically?

Answer 1

There is nothing like invokeall , but there is nothing wrong in looping via your runnables as there is also nothing like "at once" in reality:

ScheduledExecutorService pool = Executors.newScheduledThreadPool(10);
for (int i = 0; i < 10; i++) {
    pool.scheduleAtFixedRate(() -> {
        // do some work
    }, 0, 10, TimeUnit.SECONDS);
}

Or if you have a collection of Runnable :

ScheduledExecutorService pool = Executors.newScheduledThreadPool(runnables.size());
runnables.forEach((r) -> pool.scheduleAtFixedRate(r, 0, 10, TimeUnit.SECONDS));