Project Service Implementation which publishes the event.

ProjectServiceImpl.java

@Service
public class ProjectServiceImpl implements ProjectService {
 
  @Autowired
  private ApplicationEventPublisher applicationEventPublisher;
  
  @Override
  public void createProject(Project project) {
    // save project entity in the database and publish an event to send mail to project owner
    publishProjectCreatedEvent(project);
  }
  
  void publishProjectCreatedEvent(final Project project) {
    EntityCreatedEvent entityCreatedEvent = new EntityCreatedEvent(this, project);
    applicationEventPublisher.publishEvent(entityCreatedEvent);
  }
}