请教一个 springboot 和 mybatis 的问题

是这样的 我在看 spring 代码的时候 发现在 registerlistener 方法里的注释有写到不要在这里初始化 factorybean

AbstractApplicationContext.java

    protected void registerListeners() {
		// Register statically specified listeners first.
		for (ApplicationListener<?> listener : getApplicationListeners()) {
			getApplicationEventMulticaster().addApplicationListener(listener);
		}

                //↓↓↓↓↓↓↓↓↓↓↓↓注释在这里↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
		// Do not initialize FactoryBeans here: We need to leave all regular beans
		// uninitialized to let post-processors apply to them!
		String[] listenerBeanNames = getBeanNamesForType(ApplicationListener.class, true, false);
		for (String listenerBeanName : listenerBeanNames) {
			getApplicationEventMulticaster().addApplicationListenerBean(listenerBeanName);
		}

		// Publish early application events now that we finally have a multicaster...
		Set<ApplicationEvent> earlyEventsToProcess = this.earlyApplicationEvents;
		this.earlyApplicationEvents = null;
		if (earlyEventsToProcess != null) {
			for (ApplicationEvent earlyEvent : earlyEventsToProcess) {
				getApplicationEventMulticaster().multicastEvent(earlyEvent);
			}
		}
	}

但是我转去看 mybatis 的 sqlfactorybean 的时候 又看到他有实现 listener 接口

SqlSessionFactoryBean.java

public class SqlSessionFactoryBean implements FactoryBean<SqlSessionFactory>, InitializingBean, 
//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
ApplicationListener<ApplicationEvent> {

  private static final Logger LOGGER = LoggerFactory.getLogger(SqlSessionFactoryBean.class);

  private static final ResourcePatternResolver RESOURCE_PATTERN_RESOLVER = new PathMatchingResourcePatternResolver();
  private static final MetadataReaderFactory METADATA_READER_FACTORY = new CachingMetadataReaderFactory();
...

我试着注册一个 SqlSessionFactoryBean 这确实会导致这个 factorybean 在 registerListeners()中被初始化
这是怎么一回事？难道是 mybatis 的实现不规范？？？还是我对那段注释的理解不对