How to ask CompletableFuture use non-daemon threads?

Question

I have wrote following code:

 System.out.println(\"Main thread:\" + Thread.currentThread().getId());
 CompletableFuture future = CompletableFut         


        

Answer 1

Add this line:

ForkJoinPool.commonPool().awaitTermination(5, TimeUnit.SECONDS);

to the main method after running your future. I'll block until all tasks in the pool have been completed.

Blocks until all tasks have completed execution after a shutdown request, or the timeout occurs, or the current thread is interrupted, whichever happens first.

Answer 2

The javadoc for runAsync() says:

Returns a new CompletableFuture that is asynchronously completed by a task running in the ForkJoinPool.commonPool() after it runs the given action.

There is another version of runAsync() where you can pass an ExecutorService.

Thus: when the default commonPool() doesn't do what you want - then create your own ExecutorService instead.