Spring Framework FAQ: Top Questions

Spring provides a flexible eventing system to publish and listen to application-level events, using ApplicationEventPublisher and @EventListener.

📘 Steps:

1. Define a custom event class.
2. Publish the event using ApplicationEventPublisher.
3. Handle it using @EventListener.

📥 Example:

public class UserRegisteredEvent extends ApplicationEvent {
  public UserRegisteredEvent(Object source) {
    super(source);
  }
}

@Component
public class UserListener {
  @EventListener
  public void onUserRegister(UserRegisteredEvent event) {
    System.out.println("User registered!");
  }
}

🏆 Expected Output:

Prints "User registered!" when the event is triggered.

🛠️ Use Cases:

• Triggering async operations post entity actions.
• Implementing decoupled workflows or notifications.