public record UserRegisteredEvent(String email) {}
 
@Service
public class RegistrationService {
    @Autowired private ApplicationEventPublisher publisher;
 
    public void register(String email) {
        // Registration logic...
        publisher.publishEvent(new UserRegisteredEvent(email));
    }
}
 
@Component
public class EmailListener {
    @EventListener
    public void handleUserRegistration(UserRegisteredEvent event) {
        System.out.println("Sending welcome email to: " + event.email());
    }
}