What is the Future interface in Java?

What is the Future interface in Java?

The Future interface in Java represents the result of an asynchronous computation. It allows you to check if the computation is complete, retrieve the result, and handle cancellation.

How do I use the Future interface in my code?

You can use the Future interface by submitting a Callable task to an ExecutorService. It returns a Future object that you can use to retrieve the result.

Can you give me a code example?

Sure! Here's a simple example:

ExecutorService executor = Executors.newFixedThreadPool(1);
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, which wraps the original exception thrown by the task.