How do I use Java Futures?

What are Java Futures and how do I use them?

Java Futures are part of the java.util.concurrent package, allowing you to write asynchronous code. You can use them to represent the result of a computation that may not be complete yet.

Can you show me a simple example of using Java Futures?

Sure! Here's a basic example:

ExecutorService executor = Executors.newFixedThreadPool(2);
Future<Integer> future = executor.submit(() -> {
    Thread.sleep(1000);
    return 123;
});

try {
    Integer result = future.get(); // This will block until the result is available
    System.out.println("Result: " + result);
} catch (InterruptedException | ExecutionException e) {
    e.printStackTrace();
} finally {
    executor.shutdown();
}

What happens if the computation takes too long?

If the computation takes too long, you can set a timeout using the get(long timeout, TimeUnit unit) method. This will throw a TimeoutException if the result isn't available in the specified time.