SpringBoot EventListener don't receive events

Question

my EventListener annotation don't receive any Spring Event. Here is my code:

@Component
public class ProxyConfig {

    public ProxyConfig() {
        System.out.println("I can see this in the console");
    }

    @EventListener
    public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
        System.out.println("WON'T WORK :-(");  // FIXME
    }

    @EventListener
    public void test(ApplicationStartedEvent event) {
        System.out.println("WON'T WORK :-(");  // FIXME
    }
}

And here is my Application class:

@SpringBootApplication
public class Application {
    public static void main(String[] args) throws Exception {
        SpringApplication.run(MyApp.class, args);
    }
}

According to https://spring.io/blog/2015/02/11/better-application-events-in-spring-framework-4-2 and https://solidsoft.wordpress.com/2015/09/29/annotation-driven-event-listeners-in-spring-4-2/ it must be working, but it still not print my "WON'T WORK :-(" String :(

Any idea?

Thanks!

Answer 1

The two events that you are listening for are both published very early in an application's lifecycle.

ApplicationStartedEvent is sent "as early as conceivably possible as soon as a SpringApplication has been started - before the Environment or ApplicationContext is available, but after the ApplicationListeners have been registered".

ApplicationEnvironmentPreparedEvent is published "when a SpringApplication is starting up and the Environment is first available for inspection and modification."

In both cases, the event is published too early for a listener to be found via annotations and the application context. As you've observed you can use spring.factories to register your listener. Alternatively, you can use the setter method on SpringApplication.