How to configure Async and Sync Event publishers using spring

Question

I am trying to implement an event framework using spring events.I came to know that the default behavior of spring event framework is sync. But during spring context initial

Answer 1

I just had to work this out for myself. By default events are sent asynchronously except if you implement a marker interface, in my case I called it SynchronousEvent. You'll need an 'executor' in your config too (I omitted mine as it's quite customised).

@EnableAsync
@SpringBootConfiguration
public class BigFishConfig {

    @Autowired AsyncTaskExecutor executor;

    @Bean
    public ApplicationEventMulticaster applicationEventMulticaster() {
        log.debug("creating multicaster");
        return new SimpleApplicationEventMulticaster() {
            @Override
            public void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) {
                ResolvableType type = eventType != null ? eventType : ResolvableType.forInstance(event);
                if (event instanceof PayloadApplicationEvent 
                        && ((PayloadApplicationEvent) event).getPayload() instanceof SynchronousEvent) 
                    getApplicationListeners(event, type).forEach(l -> invokeListener(l, event));
                else 
                    getApplicationListeners(event, type).forEach(l -> executor.execute(() -> invokeListener(l, event)));
            }
        };
    }
...