For the first one, I believe this is the correct method [2], which takes a Callable (the other submit methods take a Runnable, which does not seem to be generic

For the first one, I believe this is the correct method [2], which takes a Callable (the other submit methods take a Runnable, which does not seem to be generic). For the second one, you can use an implementation of ExecutorService[1], which has the methods invokeAll and invokeAny. Futures in Java are similar to Promises in Javascript, in that they represent a calculation that might not be completed yet. 1. https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/concurrent/ExecutorService.html https://docs.oracle.com/en/java/javase/17/docs/api/java.base... 2. https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/concurrent/ExecutorService.html#submit(java.util.concurrent.Callable) https://docs.oracle.com/en/java/javase/17/docs/api/java.base...