Java - Custom Thread Pool vs Spring Event with Async Handlers

I am working on intercepting service layer methods and capture runtime business data and write it to some sort of persistence. After intercepting the methods, I am planning to do the persistence part asynchronously. I am working on evaluating if I should use ExecutorService or use Spring Events with Async Handler.

What could be the pros and cons of using either of the approach?

In nature , There is no difference between thread pool and spring event async. Technically , both of them lies on JUC package which is provied by jdk used to concurrently request. But the usage of them has different usage and scenario.

Thread pool

• Thread pooling is typically used for general-purpose asynchronous processing, where you want to payload tasks to separate threads for parallel execution.

following is sample code snippet of Thread pool

ExecutorService executorService = Executors.newFixedThreadPool(5);

        for (int i = 0; i < 10; i++) {
            final int taskId = i;
            executorService.execute(() -> {
                // Perform asynchronous task
                System.out.println("Executing task: " + taskId);
            });
        }

Spring Events with Async Handlers

• Spring events provide a mechanism for communication and decoupling between components within a Spring application.
• you can focus on your bussiness , not environment

following is sample code snippet of Spring Events

@Configuration
@EnableAsync
public class SpringEventsThreadPoolExample {

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SpringEventsThreadPoolExample.class);
        
        // Publish an event
        MyEvent event = new MyEvent("Hello, Spring Events with Custom Thread Pool!");
        context.publishEvent(event);
    }

    public static class MyEvent {
        private String message;

        public MyEvent(String message) {
            this.message = message;
        }

        public String getMessage() {
            return message;
        }
    }

    @Async
    @EventListener
    public void handleEvent(MyEvent event) {
        // Perform asynchronous event handling
        System.out.println("Handling event: " + event.getMessage() + " on thread: " + Thread.currentThread().getName());
    }

    @Bean
    public ThreadPoolTaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(10);
        executor.setMaxPoolSize(20);
        executor.setQueueCapacity(50);
        executor.setThreadNamePrefix("async-thread-");
        executor.initialize();
        return executor;
    }
}

As pervious determine, Spring Event is based on Thread pool , you can relaize it as a superset that provide more integrated and streamlined approach. howeveer,if you need fine-grained control over thread execution and resource allocation, or if you have a broader need for asynchronous processing beyond event handling, thread pooling might be more appropriate.