What is ExecutorService and Future in Java?

Can you explain what ExecutorService and Future are in Java?

Sure! ExecutorService is an interface in Java that provides a higher-level replacement for managing threads. It allows you to manage a pool of threads and execute tasks asynchronously.

How does Future relate to ExecutorService?

Future is an interface that represents the result of an asynchronous computation. When you submit a task to an ExecutorService, it returns a Future object that you can use to check if the task is complete and retrieve the result.

Can you give me an example of how to use them together?

Absolutely! You can create an ExecutorService, submit a Callable task, and get a Future object to retrieve the result later. Here's a simple code snippet:

ExecutorService executor = Executors.newFixedThreadPool(2);
Future<Integer> future = executor.submit(() -> {
    // some computation
    return 42;
});
Integer result = future.get(); // blocks until the result is available