How can I use Future with ExecutorService in Java?

How can I use Future with ExecutorService in Java?

You can use the Future interface to represent the result of an asynchronous computation. With ExecutorService, you can submit tasks and retrieve their results using Future.

Can you show me a simple code example?

Sure! Here's a basic example:

ExecutorService executor = Executors.newFixedThreadPool(2);
Future<Integer> future = executor.submit(() -> {
    // Simulate a long-running task
    Thread.sleep(1000);
    return 42;
});

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 task fails?

If the task fails, calling future.get() will throw an ExecutionException. You can catch this exception to handle the error.

Is there a way to cancel a task?

Yes, you can cancel a task by calling future.cancel(true). This will attempt to stop the task if it's currently running.