Demonstration of the case where inner future does receive an interruption signal - outerExecutorService lambda explicitly catch it

InnerInterruptionCorrectExample.java

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicReference;

public class InnerInterruptionCorrectExample {

    public static void main(String[] args) throws InterruptedException {

        // Create a ExecutorService for managing threads
        ExecutorService outerExecutorService = Executors.newSingleThreadExecutor();
        ExecutorService innerExecutorService = Executors.newSingleThreadExecutor();

        AtomicReference<Future<String>> innerFuture = new AtomicReference<>();
        Future<String> outerFuture = outerExecutorService.submit(() -> {
            try {
                // Create a Future to hold the result of a task
                innerFuture.set(innerExecutorService.submit(() -> {
                    try {
                        // Simulate some time-consuming operation
                        Thread.sleep(5000); // Sleep for 5 seconds
                        System.out.println("Task completed successfully!");
                        return "Done";
                    } catch (InterruptedException e) {
                        // Handle interruption
                        System.out.println("Task was interrupted!");
                        return "Error";
                    }
                }));
                return innerFuture.get().get();
            } catch (InterruptedException e) {
                Future<String> inner = innerFuture.get();
                if (inner != null) {
                    inner.cancel(true);
                }
                return "Outer Error";
            }
        });

        Thread.sleep(1000);
        outerFuture.cancel(true);

        Thread.sleep(1000);
    }
}