org.springframework.context.event.AbstractApplicationEventMulticaster

最新推荐文章于 2023-07-20 07:01:11 发布

转载最新推荐文章于 2023-07-20 07:01:11 发布 · 179 阅读

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原文链接：http://www.cnblogs.com/softidea/p/5727242.html

本文详细解析了Spring框架中事件监听机制的实现原理，重点介绍了如何通过AbstractApplicationEventMulticaster检索并组织ApplicationListener，包括从BeanFactory获取监听器及监听器Bean的过程，并对监听器进行排序。

private Collection<ApplicationListener<?>> retrieveApplicationListeners(ResolvableType eventType, Class<?> sourceType, AbstractApplicationEventMulticaster.ListenerRetriever retriever) {
    LinkedList allListeners = new LinkedList();
    Object beanFactory = this.retrievalMutex;
    LinkedHashSet listeners;
    LinkedHashSet listenerBeans;
    synchronized(this.retrievalMutex) {
        listeners = new LinkedHashSet(this.defaultRetriever.applicationListeners);
        listenerBeans = new LinkedHashSet(this.defaultRetriever.applicationListenerBeans);
    }

    Iterator beanFactory1 = listeners.iterator();

    while(beanFactory1.hasNext()) {
        ApplicationListener listener = (ApplicationListener)beanFactory1.next();
        if(this.supportsEvent(listener, eventType, sourceType)) {
            if(retriever != null) {
                retriever.applicationListeners.add(listener);
            }

            allListeners.add(listener);
        }
    }

    if(!listenerBeans.isEmpty()) {
        BeanFactory beanFactory2 = this.getBeanFactory();
        Iterator listener2 = listenerBeans.iterator();

        while(listener2.hasNext()) {
            String listenerBeanName = (String)listener2.next();

            try {
                Class listenerType = beanFactory2.getType(listenerBeanName);
                if(listenerType == null || this.supportsEvent(listenerType, eventType)) {
                    ApplicationListener listener1 = (ApplicationListener)beanFactory2.getBean(listenerBeanName, ApplicationListener.class);
                    if(!allListeners.contains(listener1) && this.supportsEvent(listener1, eventType, sourceType)) {
                        if(retriever != null) {
                            retriever.applicationListenerBeans.add(listenerBeanName);
                        }

                        allListeners.add(listener1);
                    }
                }
            } catch (NoSuchBeanDefinitionException var13) {
                ;
            }
        }
    }

    AnnotationAwareOrderComparator.sort(allListeners);
    return allListeners;
}

org.springframework.context.event.AbstractApplicationEventMulticaster

转载于:https://www.cnblogs.com/softidea/p/5727242.html