spring4.1.8 扩展实战之三：广播与监听
作者：程序员欣宸
- 2022 年 6 月 14 日
本文字数：27258 字
阅读完需：约 89 分钟
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提到广播与监听，我们常常会想到 RabbitMQ、Kafka 等消息中间件，这些常用于分布式系统中多个应用之间，有时候应用自身内部也有广播和监听的需求（例如某个核心数据发生变化后，有些业务模块希望立即被感知），这时候 spring 提供的基于 ApplicationContext 的广播与监听就派上用场了，接下来我们从原理到实践，来了解 spring 提供的这套机制吧。
全文概览
总的来说本章内容由以下部分构成：
学习广播服务的核心接口；
spring 的容器内广播和监听的源码查看；
spring 是如何支持自定义广播的；
spring 是如何支持自定义监听的；
开发一个自定义广播；
开发一个自定义监听；
ApplicationEventPublisher:广播服务的核心能力
提到 spring 容器中的广播和监听，就不得不先看看 ApplicationEventPublisher 这个接口，今天的故事都是围绕此君展开：
@FunctionalInterfacepublic interface ApplicationEventPublisher {
/** * Notify all <strong>matching</strong> listeners registered with this * application of an application event. Events may be framework events * (such as RequestHandledEvent) or application-specific events. * @param event the event to publish * @see org.springframework.web.context.support.RequestHandledEvent */ default void publishEvent(ApplicationEvent event) { publishEvent((Object) event); }
/** * Notify all <strong>matching</strong> listeners registered with this * application of an event. * <p>If the specified {@code event} is not an {@link ApplicationEvent}, * it is wrapped in a {@link PayloadApplicationEvent}. * @param event the event to publish * @since 4.2 * @see PayloadApplicationEvent */ void publishEvent(Object event);
}
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从上述代码可以看出，发送消息实际上就是在调用 ApplicationEventPublisher 接口实现类的 publishEvent 方法，接下来看看类图，了解在 spring 容器的设计中 ApplicationEventPublisher 的定位：
从上图可见，ApplicationContext 继承了 ApplicationEventPublisher，那么 ApplicationContext 的实现类自然也就具备了发送广播的能力，按照这个思路去看一下关键的抽象类 AbstractApplicationContext，果然找到了方法实现：
@Overridepublic void publishEvent(ApplicationEvent event) { publishEvent(event, null);}
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如何广播一条消息
来看一个具体的广播的例子吧，spring 容器初始化结束的时候，会执行 AbstractApplicationContext 类的 finishRefresh 方法，里面就会广播一条代表初始化结束的消息，代码如下：
protected void finishRefresh() { // Clear context-level resource caches (such as ASM metadata from scanning). clearResourceCaches();
// Initialize lifecycle processor for this context. initLifecycleProcessor();
// Propagate refresh to lifecycle processor first. getLifecycleProcessor().onRefresh();
// 广播一条消息，类型ContextRefreshedEvent代表spring容器初始化结束 publishEvent(new ContextRefreshedEvent(this));
// Participate in LiveBeansView MBean, if active. LiveBeansView.registerApplicationContext(this);}
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继续深入 publichEvent 方法内部，看到的代码如下图所示：
上图中的绿色部分的判断不成立，初始化过程中的 registerListeners 方法就会把成员变量 earlyApplicationEvents 设置为空，因此广播消息执行的是 getApplicationEventMulticaster().multicastEvent(applicationEvent, eventType)，在 ApplicationContext 的实现类中，真正的广播操作交给了成员变量 applicationEventMulticaster 来完成，没有特殊配置的话，applicationEventMulticaster 是 SimpleApplicationEventMulticaster 类型的实例（详情请看 initApplicationEventMulticaster 方法）；
打开的源码，如下所示，是否有种豁然开朗的感觉？广播的实现是如此简单明了，找到已注册的 ApplicationListener，逐个调用 invokeListener 方法，将 ApplicationListener 和事件作为入参传进去就完成了广播；
@Override public void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) { ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event)); for (final ApplicationListener<?> listener : getApplicationListeners(event, type)) { Executor executor = getTaskExecutor(); if (executor != null) { executor.execute(() -> invokeListener(listener, event)); } else { invokeListener(listener, event); } } }
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看到这里，invokeListener 方法所做的事情已经很容易猜到了，ApplicationListener 是代表监听的接口，只要调用这个接口的方法并且将 event 作为入参传进去，那么每个监听器就可以按需要自己来处理这条广播消息了，看了代码发现我们的猜测是正确的：
private void doInvokeListener(ApplicationListener listener, ApplicationEvent event) { try { //这里就是监听器收到广播时做的事情 listener.onApplicationEvent(event); } catch (ClassCastException ex) { String msg = ex.getMessage(); if (msg == null || matchesClassCastMessage(msg, event.getClass().getName())) { // Possibly a lambda-defined listener which we could not resolve the generic event type for // -> let's suppress the exception and just log a debug message. Log logger = LogFactory.getLog(getClass()); if (logger.isDebugEnabled()) { logger.debug("Non-matching event type for listener: " + listener, ex); } } else { throw ex; } } }
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另外还有个细节需要补充，这是在后面做自定义广播的时候考虑到的：**如果多线程同时发广播，会不会有线程同步的问题？**发送广播的源码一路看下来，发现操作全部在发送的线程中执行的，对各种成员变量的操作也没有出现线程同步问题，唯一有可能出现问题的地方在获取 ApplicationListener 的时候，这里用到了缓存，有缓存更新的逻辑，而 spring 已经做好了锁来确保线程同步（双重判断也做了），来看看源码，注意中文注释：
protected Collection<ApplicationListener<?>> getApplicationListeners( ApplicationEvent event, ResolvableType eventType) {
Object source = event.getSource(); Class<?> sourceType = (source != null ? source.getClass() : null); ListenerCacheKey cacheKey = new ListenerCacheKey(eventType, sourceType);
//retrieverCache是个ConcurrentHashMap ListenerRetriever retriever = this.retrieverCache.get(cacheKey); if (retriever != null) { return retriever.getApplicationListeners(); }
//如果没有从缓存中取到，就要获取了数据再返回 if (this.beanClassLoader == null || (ClassUtils.isCacheSafe(event.getClass(), this.beanClassLoader) && (sourceType == null || ClassUtils.isCacheSafe(sourceType, this.beanClassLoader)))) { // 这里有锁 synchronized (this.retrievalMutex) { retriever = this.retrieverCache.get(cacheKey); //抢到锁之后再做一次判断，因为有可能在前面BLOCK的时候，另一个抢到锁的线程已经设置好了缓存 if (retriever != null) { return retriever.getApplicationListeners(); } retriever = new ListenerRetriever(true); Collection<ApplicationListener<?>> listeners = retrieveApplicationListeners(eventType, sourceType, retriever); this.retrieverCache.put(cacheKey, retriever); return listeners; } } else { // No ListenerRetriever caching -> no synchronization necessary return retrieveApplicationListeners(eventType, sourceType, null); } }
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看到这里，我们对 spring 容器内的广播与监听已经有所了解，小结如下：
广播的核心接口是 ApplicationEventPublisher；
我们见过了如何发起一条广播，监听器如何响应广播；
接下来还不能马上动手实战，我们还有两件事情要想弄清楚：
我想发自定义的广播消息，如何具备这个发送能力？
我想接收特定的广播，如何具备这个接收能力？
接下来，继续结合 spring 源码去找上面两个问题的答案；
源码分析(如何具备消息发送能力)
先看消息生产相关的源码，在上一章《spring4.1.8扩展实战之二：Aware接口揭秘》中，我们看到 spring 容器初始化的时候会对实现了 Aware 接口的 bean 做相关的特殊处理，其中就包含 ApplicationEventPublisherAware 这个与广播发送相关的接口，代码如下(ApplicationContextAwareProcessor.java)：
private void invokeAwareInterfaces(Object bean) { if (bean instanceof Aware) { if (bean instanceof EnvironmentAware) { ((EnvironmentAware) bean).setEnvironment(this.applicationContext.getEnvironment()); } if (bean instanceof EmbeddedValueResolverAware) { ((EmbeddedValueResolverAware) bean).setEmbeddedValueResolver(this.embeddedValueResolver); } if (bean instanceof ResourceLoaderAware) { ((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext); }
//如果想在应用内发送广播，需要开发一个实现了ApplicationEventPublisherAware接口的bean，就会在此被注入一个ApplicationEventPublisher对象，借助这个对象就能发送广播了 if (bean instanceof ApplicationEventPublisherAware) { ((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext); } if (bean instanceof MessageSourceAware) { ((MessageSourceAware) bean).setMessageSource(this.applicationContext); } if (bean instanceof ApplicationContextAware) { ((ApplicationContextAware) bean).setApplicationContext(this.applicationContext); } } }
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由以上代码可见，我们可以创建一个 bean，实现了 ApplicationEventPublisherAware 接口，那么该 bean 的 setApplicationEventPublisher 方法就会被调用，通过该方法可以接收到 ApplicationEventPublisher 类型的入参，借助这个 ApplicationEventPublisher 就可以发消息了；
源码分析(如何具备消息接收能力)
在 spring 容器初始化的时候，AbstractApplicationContext 类的 prepareBeanFactory 方法中为所有 bean 准备了一个后置处理器 ApplicationListenerDetector，来看看它的 postProcessAfterInitialization 方法的代码，也就是 bean 在实例化之后要做的事情：
@Override public Object postProcessAfterInitialization(Object bean, String beanName) { if (bean instanceof ApplicationListener) { // potentially not detected as a listener by getBeanNamesForType retrieval Boolean flag = this.singletonNames.get(beanName); if (Boolean.TRUE.equals(flag)) { //注册监听器，其实就是保存在成员变量applicationEventMulticaster的成员变量defaultRetriever的集合applicationListeners中 this.applicationContext.addApplicationListener((ApplicationListener<?>) bean); } else if (Boolean.FALSE.equals(flag)) { if (logger.isWarnEnabled() && !this.applicationContext.containsBean(beanName)) { // inner bean with other scope - can't reliably process events logger.warn("Inner bean '" + beanName + "' implements ApplicationListener interface " + "but is not reachable for event multicasting by its containing ApplicationContext " + "because it does not have singleton scope. Only top-level listener beans are allowed " + "to be of non-singleton scope."); } this.singletonNames.remove(beanName); } } return bean; }
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如上所示，如果当前 bean 实现了 ApplicationListener 接口，就会调用 this.applicationContext.addApplicationListener 方法将当前 bean 注册到 applicationContext 的监听器集合中，后面有广播就直接找到这些监听器，调用每个监听器的 onApplicationEvent 方法；
现在把广播与监听的关键代码都看过了，可以开始实战了么？稍等，还有最后一个疑问要弄明白：自定义的消息监听器可以指定消息类型，所有的广播消息中，这个监听器只会收到自己指定的消息类型的广播，spring 是如何做到这一点的？
如何做到只接收指定类型的消息
此问题的答案就在 spring 源码中，但是看源码之前先自己猜测一下，自定义监听器只接收指定类型的消息，以下两种方案都可以实现：
注册监听器的时候，将监听器和消息类型绑定；
广播的时候，按照这条消息的类型去找指定了该类型的监听器，但不可能每条广播都去所有监听器里面找一遍，应该是说广播的时候会触发一次监听器和消息的类型绑定；
带着上述猜测去 spring 源码中寻找答案吧，先看注册监听器的代码，按照之前的分析，注册监听发生在后置处理器 ApplicationListenerDetector 中，看看 this.applicationContext.addApplicationListener 这一行代码的内部逻辑：
@Override public void addApplicationListener(ApplicationListener<?> listener) { Assert.notNull(listener, "ApplicationListener must not be null"); if (this.applicationEventMulticaster != null) { this.applicationEventMulticaster.addApplicationListener(listener); } else { this.applicationListeners.add(listener); } }
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最终跟踪到 AbstractApplicationEventMulticaster 类的 addApplicationListener 方法：
@Overridepublic void addApplicationListener(ApplicationListener<?> listener) { synchronized (this.retrievalMutex) { // Explicitly remove target for a proxy, if registered already, // in order to avoid double invocations of the same listener. Object singletonTarget = AopProxyUtils.getSingletonTarget(listener); if (singletonTarget instanceof ApplicationListener) { //如果因为AOP导致创建了监听类的代理，那么就要在注册列表中清除代理类 this.defaultRetriever.applicationListeners.remove(singletonTarget); } //把监听器加入集合defaultRetriever.applicationListeners中，这是个LinkedHashSet实例 this.defaultRetriever.applicationListeners.add(listener); this.retrieverCache.clear(); }}
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从以上代码我们发现了两个关键点：
AOP 是通过代理技术实现的，此时可能通过 CGLIB 生成了监听类的代理类，此类的实例如果也被注册到监听器集合中，那么广播的时候，按照消息类型就会取出两个监听器实例来了，到时候的效果就是一个消息被两个实例消费了，因此这里要先清理掉代理类；
所谓的注册监听器，其实就是把 ApplicationListener 的实现类放入一个 LinkedHashSet 的集合，此处没有任何与消息类型相关的操作，因此，监听器注册的时候并没有将消息类型和监听器绑定；
监听器注册的代码看过了，没有绑定，那么只好去看广播消息的代码了，好在前面才看过广播的代码，印象还算深刻，再次来到 SimpleApplicationEventMulticaster 的 multicastEvent 方法：
@Overridepublic void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) { ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event)); //根据消息类型取出对应的所有监听器 for (final ApplicationListener<?> listener : getApplicationListeners(event, type)) { Executor executor = getTaskExecutor(); if (executor != null) { executor.execute(() -> invokeListener(listener, event)); } else { invokeListener(listener, event); } }}
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如上述代码所示，解开我们疑问的关键点就在**getApplicationListeners(event, type)**这段代码了，也就是说在发送消息的时候根据类型去找所有对应的监听器，展开这个方法一探究竟：
protected Collection<ApplicationListener<?>> getApplicationListeners( ApplicationEvent event, ResolvableType eventType) {
Object source = event.getSource();
Class<?> sourceType = (source != null ? source.getClass() : null); //缓存的key有两个维度：消息来源+消息类型（关于消息来源可见ApplicationEvent构造方法的入参） ListenerCacheKey cacheKey = new ListenerCacheKey(eventType, sourceType);
// retrieverCache是ConcurrentHashMap对象，所以是线程安全的， // ListenerRetriever中有个监听器的集合，并有些简单的逻辑封装，调用它的getApplicationListeners方法返回的监听类集合是排好序的(order注解排序) ListenerRetriever retriever = this.retrieverCache.get(cacheKey); if (retriever != null) { //如果retrieverCache中找到对应的监听器集合，就立即返回了 return retriever.getApplicationListeners(); }
if (this.beanClassLoader == null || (ClassUtils.isCacheSafe(event.getClass(), this.beanClassLoader) && (sourceType == null || ClassUtils.isCacheSafe(sourceType, this.beanClassLoader)))) { //如果retrieverCache中没有数据，就在此查出数据并放入缓存， //先加锁 synchronized (this.retrievalMutex) { //双重判断的第二重，避免自己在BLOCK的时候其他线程已经将数据放入缓存了 retriever = this.retrieverCache.get(cacheKey); if (retriever != null) { return retriever.getApplicationListeners(); } //新建一个ListenerRetriever对象 retriever = new ListenerRetriever(true); //retrieveApplicationListeners方法复制找出某个消息类型加来源类型对应的所有监听器 Collection<ApplicationListener<?>> listeners = retrieveApplicationListeners(eventType, sourceType, retriever); //存入retrieverCache this.retrieverCache.put(cacheKey, retriever); //返回结果 return listeners; } } else { // No ListenerRetriever caching -> no synchronization necessary return retrieveApplicationListeners(eventType, sourceType, null); }}
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上述代码解开了所有疑惑：**在广播消息的时刻，如果某个类型的消息在缓存中找不到对应的监听器集合，就调用 retrieveApplicationListeners 方法去找出符合条件的所有监听器，然后放入这个集合；**这和之前的猜测匹配度挺高的...
retrieveApplicationListeners 方法在面对各种监听器的时候处理逻辑过于复杂，就不在这里展开了；
至此，我们对广播和监听的原理已经有了较全面的认识，可以动手实战了；
开发一个自定义广播
现在基于 maven 创建一个 SpringBoot 的 web 工程 customizeapplicationevent，在工程中自定义一个发送广播的 bean，在收到一个 web 请求时，利用该 bean 发出广播；
创建工程 customizeapplicationevent，pom.xml 如下：
<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.bolingcavalry</groupId> <artifactId>customizeapplicationevent</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>customizeapplicationevent</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.4.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build></project>
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自定义一个消息类型 CustomizeEvent：
package com.bolingcavalry.customizeapplicationevent.event;
import org.springframework.context.ApplicationContext;import org.springframework.context.event.ApplicationContextEvent;
/** * @Description : 自定义的消息类型 * @Author : zq2599@gmail.com * @Date : 2018-08-16 06:09 */public class CustomizeEvent extends ApplicationContextEvent { public CustomizeEvent(ApplicationContext source) { super(source); }}
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自定义广播发送者 CustomizePublisher，除了用到 ApplicationEventPublisher，还要用到 ApplicationContext（构造 CustomizeEvent 对象的时候要用），所以要实现两个 Aware 接口：
package com.bolingcavalry.customizeapplicationevent.publish;
import com.bolingcavalry.customizeapplicationevent.event.CustomizeEvent;import com.bolingcavalry.customizeapplicationevent.util.Utils;import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;import org.springframework.context.ApplicationEventPublisher;import org.springframework.context.ApplicationEventPublisherAware;import org.springframework.stereotype.Service;
/** * @Description : 自定义的广播发送器 * @Author : zq2599@gmail.com * @Date : 2018-08-16 06:09 */@Servicepublic class CustomizePublisher implements ApplicationEventPublisherAware, ApplicationContextAware {
private ApplicationEventPublisher applicationEventPublisher;
private ApplicationContext applicationContext;
@Override public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) { this.applicationEventPublisher = applicationEventPublisher; Utils.printTrack("applicationEventPublisher is set : " + applicationEventPublisher); }
@Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.applicationContext = applicationContext; }
/** * 发送一条广播 */ public void publishEvent(){ applicationEventPublisher.publishEvent(new CustomizeEvent(applicationContext)); }}
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做一个 controller，这样就能通过 web 请求来触发一次广播了：
package com.bolingcavalry.customizeapplicationevent.controller;
import com.bolingcavalry.customizeapplicationevent.publish.CustomizePublisher;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;
import java.util.Date;
/** * @Description : 收到web请求后发送一条广播 * @Author : zq2599@gmail.com * @Date : 2018-08-16 06:45 */@RestControllerpublic class CustomizePublishEventController {
@Autowired private CustomizePublisher customizePublisher;
@RequestMapping("/publish") public String publish(){
customizePublisher.publishEvent();
return "publish finish, " + new Date(); }}
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自定义广播的代码已经完成了，不过现在即使把消息发出去了也不能验证是否发送成功，先不要运行工程，接下来把自定义消息监听也做了吧；
开发两个自定义监听器
我们要做两个自定义监听器；
第一个监听类在泛型中定义的类型是 ApplicationEvent，即接收所有广播消息；
package com.bolingcavalry.customizeapplicationevent.listener;
import com.bolingcavalry.customizeapplicationevent.util.Utils;import org.springframework.context.ApplicationEvent;import org.springframework.context.ApplicationListener;import org.springframework.stereotype.Service;
/** * @Description : 自定义的系统广播监听器，接收所有类型的消息 * @Author : zq2599@gmail.com * @Date : 2018-08-15 14:53 */@Servicepublic class AllEventListener implements ApplicationListener<ApplicationEvent>{
@Override public void onApplicationEvent(ApplicationEvent event) { //为了便于了解调用栈，在日志中打印当前堆栈 Utils.printTrack("onApplicationEvent : " + event); }}
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第二个监听类在泛型中定义的类型是 CustomizeEvent，即只接收 CustomizeEvent 类型的消息；
package com.bolingcavalry.customizeapplicationevent.listener;
import com.bolingcavalry.customizeapplicationevent.event.CustomizeEvent;import com.bolingcavalry.customizeapplicationevent.util.Utils;import org.springframework.context.ApplicationEvent;import org.springframework.context.ApplicationListener;import org.springframework.stereotype.Service;
/** * @Description : 自定义的系统广播监听器，只接受CustomizeEvent类型的消息 * @Author : zq2599@gmail.com * @Date : 2018-08-15 14:53 */@Servicepublic class CustomizeEventListener implements ApplicationListener<CustomizeEvent>{
@Override public void onApplicationEvent(CustomizeEvent event) { //为了便于了解调用栈，在日志中打印当前堆栈 Utils.printTrack("onApplicationEvent : " + event); }}
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把工程运行起来，先见到 CustomizePublisher 被注入 ApplicationEventPublisher 对象的日志，然后看到 AllEventListener 收到广播后打印的日志，如下所示，可通过日志中的堆栈信息印证我们之前看过的广播监听相关源码：
2018-08-16 18:35:15.656 INFO 7864 --- [ main] c.b.c.util.Utils : applicationEventPublisher is set : org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@37e547da: startup date [Thu Aug 16 18:35:14 CST 2018]; root of context hierarchy************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.publish.CustomizePublisher.setApplicationEventPublisher() 27 <-org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces() 114 <-org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization() 96 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization() 416 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean() 1,691 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean() 573 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean() 495 <-org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0() 317 <-org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton() 222 <-org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean() 315 <-org.springframework.beans.factory.support.AbstractBeanFactory.getBean() 199 <-org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate() 251 <-org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency() 1,135 <-org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency() 1,062 <-org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject() 583 <-org.springframework.beans.factory.annotation.InjectionMetadata.inject() 91 <-org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues() 372 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean() 1,341 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean() 572 <-org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean() 495 <-org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0() 317 <-org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton() 222 <-org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean() 315 <-org.springframework.beans.factory.support.AbstractBeanFactory.getBean() 199 <-org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons() 759 <-org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization() 869 <-org.springframework.context.support.AbstractApplicationContext.refresh() 550 <-org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh() 140 <-org.springframework.boot.SpringApplication.refresh() 762 <-org.springframework.boot.SpringApplication.refreshContext() 398 <-org.springframework.boot.SpringApplication.run() 330 <-org.springframework.boot.SpringApplication.run() 1,258 <-org.springframework.boot.SpringApplication.run() 1,246 <-com.bolingcavalry.customizeapplicationevent.CustomizeapplicationeventApplication.main() 10************************************************************2018-08-16 18:35:15.732 INFO 7864 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2018-08-16 18:35:15.875 INFO 7864 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@37e547da: startup date [Thu Aug 16 18:35:14 CST 2018]; root of context hierarchy2018-08-16 18:35:15.919 INFO 7864 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/publish]}" onto public java.lang.String com.bolingcavalry.customizeapplicationevent.controller.CustomizePublishEventController.publish()2018-08-16 18:35:15.924 INFO 7864 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)2018-08-16 18:35:15.925 INFO 7864 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)2018-08-16 18:35:15.945 INFO 7864 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2018-08-16 18:35:15.946 INFO 7864 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]2018-08-16 18:35:16.059 INFO 7864 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup2018-08-16 18:35:16.069 INFO 7864 --- [ main] c.b.c.util.Utils : onApplicationEvent : org.springframework.context.event.ContextRefreshedEvent[source=org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@37e547da: startup date [Thu Aug 16 18:35:14 CST 2018]; root of context hierarchy]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.context.support.AbstractApplicationContext.finishRefresh() 888 <-org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh() 161 <-org.springframework.context.support.AbstractApplicationContext.refresh() 553 <-org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh() 140 <-org.springframework.boot.SpringApplication.refresh() 762 <-org.springframework.boot.SpringApplication.refreshContext() 398 <-org.springframework.boot.SpringApplication.run() 330 <-org.springframework.boot.SpringApplication.run() 1,258 <-org.springframework.boot.SpringApplication.run() 1,246 <-com.bolingcavalry.customizeapplicationevent.CustomizeapplicationeventApplication.main() 10************************************************************2018-08-16 18:35:16.094 INFO 7864 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''2018-08-16 18:35:16.096 INFO 7864 --- [ main] c.b.c.util.Utils : onApplicationEvent : org.springframework.boot.web.servlet.context.ServletWebServerInitializedEvent[source=org.springframework.boot.web.embedded.tomcat.TomcatWebServer@1c25b8a7]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh() 164 <-org.springframework.context.support.AbstractApplicationContext.refresh() 553 <-org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh() 140 <-org.springframework.boot.SpringApplication.refresh() 762 <-org.springframework.boot.SpringApplication.refreshContext() 398 <-org.springframework.boot.SpringApplication.run() 330 <-org.springframework.boot.SpringApplication.run() 1,258 <-org.springframework.boot.SpringApplication.run() 1,246 <-com.bolingcavalry.customizeapplicationevent.CustomizeapplicationeventApplication.main() 10************************************************************2018-08-16 18:35:16.099 INFO 7864 --- [ main] b.c.CustomizeapplicationeventApplication : Started CustomizeapplicationeventApplication in 2.098 seconds (JVM running for 3.161)2018-08-16 18:35:16.101 INFO 7864 --- [ main] c.b.c.util.Utils : onApplicationEvent : org.springframework.boot.context.event.ApplicationStartedEvent[source=org.springframework.boot.SpringApplication@77b7ffa4]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.boot.context.event.EventPublishingRunListener.started() 97 <-org.springframework.boot.SpringApplicationRunListeners.started() 72 <-org.springframework.boot.SpringApplication.run() 337 <-org.springframework.boot.SpringApplication.run() 1,258 <-org.springframework.boot.SpringApplication.run() 1,246 <-com.bolingcavalry.customizeapplicationevent.CustomizeapplicationeventApplication.main() 10************************************************************2018-08-16 18:35:16.103 INFO 7864 --- [ main] c.b.c.util.Utils : onApplicationEvent : org.springframework.boot.context.event.ApplicationReadyEvent[source=org.springframework.boot.SpringApplication@77b7ffa4]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.boot.context.event.EventPublishingRunListener.running() 103 <-org.springframework.boot.SpringApplicationRunListeners.running() 78 <-org.springframework.boot.SpringApplication.run() 346 <-org.springframework.boot.SpringApplication.run() 1,258 <-org.springframework.boot.SpringApplication.run() 1,246 <-com.bolingcavalry.customizeapplicationevent.CustomizeapplicationeventApplication.main() 10************************************************************
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在浏览器输入地址：http://localhost:8080/publish，触发一次 CustomizeEvent 类型的消息广播，日志显示 CustomizeEventListener 和 AllEventListener 都收到了消息，如下：
2018-08-16 18:44:18.879 INFO 7864 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet'2018-08-16 18:44:18.880 INFO 7864 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started2018-08-16 18:44:18.912 INFO 7864 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 32 ms2018-08-16 18:44:18.958 INFO 7864 --- [nio-8080-exec-1] c.b.c.util.Utils : onApplicationEvent : com.bolingcavalry.customizeapplicationevent.event.CustomizeEvent[source=org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@37e547da: startup date [Thu Aug 16 18:35:14 CST 2018]; root of context hierarchy]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-com.bolingcavalry.customizeapplicationevent.publish.CustomizePublisher.publishEvent() 39 <-com.bolingcavalry.customizeapplicationevent.controller.CustomizePublishEventController.publish() 24 <-sun.reflect.NativeMethodAccessorImpl.invoke0() -2 <-sun.reflect.NativeMethodAccessorImpl.invoke() 62 <-sun.reflect.DelegatingMethodAccessorImpl.invoke() 43 <-java.lang.reflect.Method.invoke() 498 <-org.springframework.web.method.support.InvocableHandlerMethod.doInvoke() 209 <-org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest() 136 <-org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle() 102 <-org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod() 877 <-org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal() 783 <-org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle() 87 <-org.springframework.web.servlet.DispatcherServlet.doDispatch() 991 <-org.springframework.web.servlet.DispatcherServlet.doService() 925 <-org.springframework.web.servlet.FrameworkServlet.processRequest() 974 <-org.springframework.web.servlet.FrameworkServlet.doGet() 866 <-javax.servlet.http.HttpServlet.service() 635 <-org.springframework.web.servlet.FrameworkServlet.service() 851 <-javax.servlet.http.HttpServlet.service() 742 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 231 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.tomcat.websocket.server.WsFilter.doFilter() 52 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.RequestContextFilter.doFilterInternal() 99 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal() 109 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal() 93 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal() 200 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.catalina.core.StandardWrapperValve.invoke() 198 <-org.apache.catalina.core.StandardContextValve.invoke() 96 <-org.apache.catalina.authenticator.AuthenticatorBase.invoke() 493 <-org.apache.catalina.core.StandardHostValve.invoke() 140 <-org.apache.catalina.valves.ErrorReportValve.invoke() 81 <-org.apache.catalina.core.StandardEngineValve.invoke() 87 <-org.apache.catalina.connector.CoyoteAdapter.service() 342 <-org.apache.coyote.http11.Http11Processor.service() 800 <-org.apache.coyote.AbstractProcessorLight.process() 66 <-org.apache.coyote.AbstractProtocol$ConnectionHandler.process() 800 <-org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun() 1,471 <-org.apache.tomcat.util.net.SocketProcessorBase.run() 49 <-java.util.concurrent.ThreadPoolExecutor.runWorker() 1,142 <-java.util.concurrent.ThreadPoolExecutor$Worker.run() 617 <-org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() 61 <-java.lang.Thread.run() 745************************************************************2018-08-16 18:44:18.964 INFO 7864 --- [nio-8080-exec-1] c.b.c.util.Utils : onApplicationEvent : com.bolingcavalry.customizeapplicationevent.event.CustomizeEvent[source=org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@37e547da: startup date [Thu Aug 16 18:35:14 CST 2018]; root of context hierarchy]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.CustomizeEventListener.onApplicationEvent() 19 <-com.bolingcavalry.customizeapplicationevent.listener.CustomizeEventListener.onApplicationEvent() 14 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-com.bolingcavalry.customizeapplicationevent.publish.CustomizePublisher.publishEvent() 39 <-com.bolingcavalry.customizeapplicationevent.controller.CustomizePublishEventController.publish() 24 <-sun.reflect.NativeMethodAccessorImpl.invoke0() -2 <-sun.reflect.NativeMethodAccessorImpl.invoke() 62 <-sun.reflect.DelegatingMethodAccessorImpl.invoke() 43 <-java.lang.reflect.Method.invoke() 498 <-org.springframework.web.method.support.InvocableHandlerMethod.doInvoke() 209 <-org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest() 136 <-org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle() 102 <-org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod() 877 <-org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal() 783 <-org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle() 87 <-org.springframework.web.servlet.DispatcherServlet.doDispatch() 991 <-org.springframework.web.servlet.DispatcherServlet.doService() 925 <-org.springframework.web.servlet.FrameworkServlet.processRequest() 974 <-org.springframework.web.servlet.FrameworkServlet.doGet() 866 <-javax.servlet.http.HttpServlet.service() 635 <-org.springframework.web.servlet.FrameworkServlet.service() 851 <-javax.servlet.http.HttpServlet.service() 742 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 231 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.tomcat.websocket.server.WsFilter.doFilter() 52 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.RequestContextFilter.doFilterInternal() 99 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal() 109 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal() 93 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal() 200 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.catalina.core.StandardWrapperValve.invoke() 198 <-org.apache.catalina.core.StandardContextValve.invoke() 96 <-org.apache.catalina.authenticator.AuthenticatorBase.invoke() 493 <-org.apache.catalina.core.StandardHostValve.invoke() 140 <-org.apache.catalina.valves.ErrorReportValve.invoke() 81 <-org.apache.catalina.core.StandardEngineValve.invoke() 87 <-org.apache.catalina.connector.CoyoteAdapter.service() 342 <-org.apache.coyote.http11.Http11Processor.service() 800 <-org.apache.coyote.AbstractProcessorLight.process() 66 <-org.apache.coyote.AbstractProtocol$ConnectionHandler.process() 800 <-org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun() 1,471 <-org.apache.tomcat.util.net.SocketProcessorBase.run() 49 <-java.util.concurrent.ThreadPoolExecutor.runWorker() 1,142 <-java.util.concurrent.ThreadPoolExecutor$Worker.run() 617 <-org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() 61 <-java.lang.Thread.run() 745************************************************************2018-08-16 18:44:18.995 INFO 7864 --- [nio-8080-exec-1] c.b.c.util.Utils : onApplicationEvent : ServletRequestHandledEvent: url=[/publish]; client=[0:0:0:0:0:0:0:1]; method=[GET]; servlet=[dispatcherServlet]; session=[null]; user=[null]; time=[66ms]; status=[OK]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.web.servlet.FrameworkServlet.publishRequestHandledEvent() 1,074 <-org.springframework.web.servlet.FrameworkServlet.processRequest() 1,005 <-org.springframework.web.servlet.FrameworkServlet.doGet() 866 <-javax.servlet.http.HttpServlet.service() 635 <-org.springframework.web.servlet.FrameworkServlet.service() 851 <-javax.servlet.http.HttpServlet.service() 742 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 231 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.tomcat.websocket.server.WsFilter.doFilter() 52 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.RequestContextFilter.doFilterInternal() 99 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal() 109 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal() 93 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal() 200 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.catalina.core.StandardWrapperValve.invoke() 198 <-org.apache.catalina.core.StandardContextValve.invoke() 96 <-org.apache.catalina.authenticator.AuthenticatorBase.invoke() 493 <-org.apache.catalina.core.StandardHostValve.invoke() 140 <-org.apache.catalina.valves.ErrorReportValve.invoke() 81 <-org.apache.catalina.core.StandardEngineValve.invoke() 87 <-org.apache.catalina.connector.CoyoteAdapter.service() 342 <-org.apache.coyote.http11.Http11Processor.service() 800 <-org.apache.coyote.AbstractProcessorLight.process() 66 <-org.apache.coyote.AbstractProtocol$ConnectionHandler.process() 800 <-org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun() 1,471 <-org.apache.tomcat.util.net.SocketProcessorBase.run() 49 <-java.util.concurrent.ThreadPoolExecutor.runWorker() 1,142 <-java.util.concurrent.ThreadPoolExecutor$Worker.run() 617 <-org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() 61 <-java.lang.Thread.run() 745************************************************************2018-08-16 18:44:19.392 INFO 7864 --- [nio-8080-exec-2] c.b.c.util.Utils : onApplicationEvent : ServletRequestHandledEvent: url=[/favicon.ico]; client=[0:0:0:0:0:0:0:1]; method=[GET]; servlet=[dispatcherServlet]; session=[null]; user=[null]; time=[19ms]; status=[OK]************************************************************java.lang.Thread.getStackTrace() 1,556 <-com.bolingcavalry.customizeapplicationevent.util.Utils.printTrack() 25 <-com.bolingcavalry.customizeapplicationevent.listener.AllEventListener.onApplicationEvent() 18 <-org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener() 172 <-org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener() 165 <-org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent() 139 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 400 <-org.springframework.context.support.AbstractApplicationContext.publishEvent() 354 <-org.springframework.web.servlet.FrameworkServlet.publishRequestHandledEvent() 1,074 <-org.springframework.web.servlet.FrameworkServlet.processRequest() 1,005 <-org.springframework.web.servlet.FrameworkServlet.doGet() 866 <-javax.servlet.http.HttpServlet.service() 635 <-org.springframework.web.servlet.FrameworkServlet.service() 851 <-javax.servlet.http.HttpServlet.service() 742 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 231 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.tomcat.websocket.server.WsFilter.doFilter() 52 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.RequestContextFilter.doFilterInternal() 99 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal() 109 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal() 93 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal() 200 <-org.springframework.web.filter.OncePerRequestFilter.doFilter() 107 <-org.apache.catalina.core.ApplicationFilterChain.internalDoFilter() 193 <-org.apache.catalina.core.ApplicationFilterChain.doFilter() 166 <-org.apache.catalina.core.StandardWrapperValve.invoke() 198 <-org.apache.catalina.core.StandardContextValve.invoke() 96 <-org.apache.catalina.authenticator.AuthenticatorBase.invoke() 493 <-org.apache.catalina.core.StandardHostValve.invoke() 140 <-org.apache.catalina.valves.ErrorReportValve.invoke() 81 <-org.apache.catalina.core.StandardEngineValve.invoke() 87 <-org.apache.catalina.connector.CoyoteAdapter.service() 342 <-org.apache.coyote.http11.Http11Processor.service() 800 <-org.apache.coyote.AbstractProcessorLight.process() 66 <-org.apache.coyote.AbstractProtocol$ConnectionHandler.process() 800 <-org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun() 1,471 <-org.apache.tomcat.util.net.SocketProcessorBase.run() 49 <-java.util.concurrent.ThreadPoolExecutor.runWorker() 1,142 <-java.util.concurrent.ThreadPoolExecutor$Worker.run() 617 <-org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run() 61 <-java.lang.Thread.run() 745************************************************************
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实战完成，自定义的广播发送和监听都达到了预期；
实战源码下载
本章实战的源码可以在 github 下载，地址和链接信息如下表所示：
这个 git 项目中有多个文件夹，本章源码在文件夹 customizeapplicationevent 下，如下图红框所示：
至此，spring 实战的广播与监听部分，我们通过先看源码再动手实践的方式做了比较深入的了解，希望本次实战能对你在设计进程内的消息服务时有所帮助，借助 spring 容器和扩展能力，设计出更加简洁高效的服务；
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发布于: 2022 年 06 月 14 日阅读数: 39
版权声明: 本文为 InfoQ 作者【程序员欣宸】的原创文章。
原文链接:【http://xie.infoq.cn/article/773474185335bf3949951cec4】。文章转载请联系作者。
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