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SpringBoot启动关键点解析及启动日志追溯

<!doctype html>Spring Boot 源码阅读2

目录1 SpringBoot启动关键点解析1.1 new SpringApplication(primarySources)部分1.2 run(args)部分1.2.1 ConfigurableEnvironment提供的服务（关注的信息）1.2.2 ConfigurableApplicationContext1.2.3 SpringApplication.prepareContext1.2.4 SpringApplication.refreshContext1.2.4.1 AbstractApplicationContext.finishBeanFactoryInitialization1.2.4.2 DefaultListableBeanFactory.preInstantiateSingletons1.2.5 默认的关闭钩子1.3 启动日志分析1.3.1 虚拟机启动日志打印1.3.2 Banner打印1.3.3 环境信息打印1.3.4 web服务启动日志1.3.5 实例化相关信息打印1.3.6 web启动打印1.3.7 启动成功日志

1 SpringBoot启动关键点解析

启动核心分为两部分new SpringApplication(primarySources)和执行run(args)方法，

1.1 new SpringApplication(primarySources)部分

部分的核心是从META/spring.facteries中读取ApplicationContextInitializer和ApplicationListener配置，然后直接通过反射实例化，实例化+排序完毕后，把应用初始化器ApplicationContextInitializer和应用监听放到SpringApplication对象上

1.2 run(args)部分

run部分最核心的构建ConfigurableApplicationContext这个上下文对象对象，构建完毕后当前线程是会返回的。

run方法实现为：

 
 

x
 
 
 
/**
 * Run the Spring application, creating and refreshing a new * {@link ApplicationContext}. * @param args the application arguments (usually passed from a Java main method) * @return a running {@link ApplicationContext}
 */
public ConfigurableApplicationContext run(String... args) {   StopWatch stopWatch = new StopWatch();   stopWatch.start();   ConfigurableApplicationContext context = null;   Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();   configureHeadlessProperty();   SpringApplicationRunListeners listeners = getRunListeners(args);//获取SpringApplicationRunListener的监听，当前只有org.springframework.boot.context.event.EventPublishingRunListener一个   listeners.starting(); //调度监听的start方法，这里事件发布监听的start方法是发布了一个ApplicationStartingEvent事件   try {      ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);       //创建一个ConfigurableEnvironment(理解参见1.2.1),初始化       //让configurationProperties的属性源始终位于第一（应该是保证最高优先级）       //调度应用监听执行environmentPrepared， EventPublishingRunListener一个也就是发布一个ApplicationEnvironmentPreparedEvent事件       //将获取到的environment中的spring.main配置绑定到SpringApplication的source中（这部分用到了一个Binder语法，没有看懂）      ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);// 从环境中读取spring.beaninfo.ignore并设置为系统属性      configureIgnoreBeanInfo(environment);        //Banner打印      Banner printedBanner = printBanner(environment);        //创建ConfigurableApplicationContext对象，这个上下文对象关注的信息有点多，参见（1.2.2）      context = createApplicationContext();       //从META_DATA/spring.facteries中读取SpringBootExceptionReporter的配置并进行实例化，默认读取出来是org.springframework.boot.diagnostics.FailureAnalyzers      exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,            new Class[] { ConfigurableApplicationContext.class }, context);       //准备环境，参见（1.2.3），主要为设置上下文对象的容器属性       //调度一开始读取的initializer的执行initialize方法，之后调度监听器的contextPrepared，发布ApplicationContextInitializedEvent       //打印开始和profile的日志
       //把拿到的标签类进行beanDefinition注册，之后调度监听器的contextLoaded，发布ApplicationPreparedEvent
      prepareContext(context, environment, listeners, applicationArguments, printedBanner);
       //刷新上下文，参见（1.2.4）,
      refreshContext(context);
      afterRefresh(context, applicationArguments);

      stopWatch.stop();
      if (this.logStartupInfo) {
          //打印已启动信息以及耗时情况

         new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
      }
       //调度监听器的started的方法，此处默认为发布一个ApplicationStartedEvent事件
      listeners.started(context);
       //找注册的ApplicationRunner、CommandLineRunner，排序后分别调度对应的ApplicationRunner和CommandLineRunner （spring-boot的启动后自动执行建表语句好像就是通过这个机制实现。这里可以做一些启动后就需要立马执行的事）。注意，此时刚发布ApplicationStartedEvent而尚未发布ApplicationReadyEvent
      callRunners(context, applicationArguments);   }   catch (Throwable ex) {      handleRunFailure(context, ex, exceptionReporters, listeners);      throw new IllegalStateException(ex);   }​   try {       //调度监听器的running方法，此处默认为发布一个ApplicationReadyEvent事件。
       //执行完次应该代表服务正式可用
      listeners.running(context);   }   catch (Throwable ex) {      handleRunFailure(context, ex, exceptionReporters, null);      throw new IllegalStateException(ex);   }   return context;}
 
 

1.2.1 ConfigurableEnvironment提供的服务（关注的信息）

从环境接口的方法来看，它主要关注与当前应用的profile、propertySource、systemEnvironment、systemProperties、getConversionService；环境本身重要的信息有webApplicationType（ConversionService是干啥的？？）

1.2.2 ConfigurableApplicationContext

从名字解读是可配置的应用容器对象。关注的内容非常多，包括应用监听器(ApplicationListener)、应用的后置处理器(PosProcessor)、应用的协议解析器(ProtocolResolver)、bean管理、类加载器、环境对象管理(Environment)、消息对象管理(Message)、资源对象管理(Resouce)等.

容器对象是根据应用类型有所不同的，SERVLET创建的是org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext的容器对象，该对象在构造时会构造一个AnnotatedBeanDefinitionReader和ClassPathBeanDefinitionScanner对象。

AnnotatedBeanDefinitionReader对象同时设置了beanFactory的dependencyComparator、autowireCandidateResolver实例，进行了ConfigurationClassPostProcessor、AutowiredAnnotationBeanPostProcessor、CommonAnnotationBeanPostProcessor、EventListenerMethodProcessor、DefaultEventListenerFactory的bean声明。

ClassPathBeanDefinitionScanner对象创建时同时TypeFilter的实例（包含AnnotationTypeFilter(Component.class)）

1.2.3 SpringApplication.prepareContext

代码如下：

 
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private void prepareContext(ConfigurableApplicationContext context, ConfigurableEnvironment environment,
      SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments, Banner printedBanner) {   context.setEnvironment(environment);    //把SpringApplication上的部分信息绑定到context上   postProcessApplicationContext(context);    //拿到之前从配置中读取并实例化的initializer，执行initialize(context)方法 ！！它们大部分都是给容器设置一些值   applyInitializers(context);    //调度监听器的contextPrepared，此处为发布一个ApplicationContextInitializedEvent事件   listeners.contextPrepared(context);   if (this.logStartupInfo) {       //打印应用启动的日志      logStartupInfo(context.getParent() == null);       //打印profile加载情况      logStartupProfileInfo(context);   }   // Add boot specific singleton beans   ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();   //把ApplicationArguments注册成单例bean   beanFactory.registerSingleton("springApplicationArguments", applicationArguments);   if (printedBanner != null) {       //如果Banner非空，也注册成单例bean      beanFactory.registerSingleton("springBootBanner", printedBanner);   }   if (beanFactory instanceof DefaultListableBeanFactory) {       //设置bean工程的allowBeanDefinitionOverriding属性      ((DefaultListableBeanFactory) beanFactory)            .setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);   }   if (this.lazyInitialization) {       //如果是lazyInitialization模式（默认为false），给上下文追加一个LazyInitializationBeanFactoryPostProcessor的后置处理器实例      context.addBeanFactoryPostProcessor(new LazyInitializationBeanFactoryPostProcessor());   }   // Load the sources -》注册的入口类被识别为私有源，需要加入更多的标签类看看是否是在这里就已经被全部识别   Set<Object> sources = getAllSources();   Assert.notEmpty(sources, "Sources must not be empty");   //把识别出来的源都进行beanDefinition注册   load(context, sources.toArray(new Object[0]));   //调度监听器的contextLoaded方法，这里表现为发布一个ApplicationPreparedEvent事件   listeners.contextLoaded(context);}

默认读取并实例化的初始化器有：

0 = {DelegatingApplicationContextInitializer@3271} 1 = {SharedMetadataReaderFactoryContextInitializer@3272} 2 = {ContextIdApplicationContextInitializer@3273} 3 = {ConfigurationWarningsApplicationContextInitializer@3274} 4 = {RSocketPortInfoApplicationContextInitializer@3275} 5 = {ServerPortInfoApplicationContextInitializer@3276} 6 = {ConditionEvaluationReportLoggingListener@3277}

1.2.4 SpringApplication.refreshContext

 
private void refreshContext(ConfigurableApplicationContext context) {
   refresh(context);   if (this.registerShutdownHook) {      try {          //注册关闭虚拟机的钩子         context.registerShutdownHook();       }      catch (AccessControlException ex) {         // Not allowed in some environments.      }   }}​protected void refresh(ApplicationContext applicationContext) {Assert.isInstanceOf(AbstractApplicationContext.class, applicationContext);((AbstractApplicationContext) applicationContext).refresh();}​//AbstractApplicationContext.refresh    @Overridepublic void refresh() throws BeansException, IllegalStateException {    synchronized (this.startupShutdownMonitor) {        // Prepare this context for refreshing. //初始化当前容器的一些属性        prepareRefresh();​        // Tell the subclass to refresh the internal bean factory. //设置工厂的序列化id        ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();​        // Prepare the bean factory for use in this context.         //初始化beanFactory的一些属性，创建一些实例类，也注册了几个beanDefinition        //设置内容包括 beanClassLoader、StandardBeanExpressionResolver、ResourceEditorRegistrar、ApplicationContextAwareProcessor        //设置忽略的依赖接口EnvironmentAware、EmbeddedValueResolverAware、ResourceLoaderAware、ApplicationEventPublisherAware、MessageSourceAware、ApplicationContextAware        //注册BeanFactory（SpringApplication）、ResourceLoader(ConfigurableApplicationContext)、ApplicationEventPublisher（ConfigurableApplicationContext）、ApplicationContext（ConfigurableApplicationContext）        //追加beanPostProcessors：ApplicationListenerDetector        //管控environment、systemProperties、systemEnvironment单例        prepareBeanFactory(beanFactory);​        try {            // Allows post-processing of the bean factory in context subclasses.            //设置一个WebApplicationContextServletContextAwareProcessor后置处理器            //设置忽略接口依赖ServletContextAware                        //注册并实例化register和session的Scope，在注册过程中通过WebApplicationContextUtils.registerWebApplicationScopes(getBeanFactory());跳转到sprig-web中            //注册ServletRequest、ServletResponse、HttpSession、WebRequest的解析以来            //!!!注意，也就这里引入了对于spring-web的支持 （spring-boot通过spring-boot-starter..等是引入了spring-web的...）            //这里总结就是注册了spring-web相关的信息            postProcessBeanFactory(beanFactory);​            // Invoke factory processors registered as beans in the context.            //先是收集beanFactory中直接已经注册好的BeanDefinitionRegistryPostProcessor，按registryProcessors、regularPostProcessors两种类别收集，在所有BeanDefinitionRegistryPostProcessor类后置执行方法最后执行，最后先执行按registryProcessors再执行regularPostProcessors            //然后从bean定义集合中找是BeanDefinitionRegistryPostProcessor类别，同时带PriorityOrdered标签的，实例化后执行后置方法            //再从bean定义集合中找是BeanDefinitionRegistryPostProcessor类别，同时带Ordered标签的，实例化后执行后置方法            //最后执行其余没有被实例化的BeanDefinitionRegistryPostProcessor，实例化并执行                                    //然后处理BeanFactoryPostProcessor类别            //按PriorityOrdered、Ordered、其他来收集并实例化BeanFactoryPostProcessor            //之后是分别排序和执行PriorityOrdered、Ordered、其他 类别的BeanFactoryPostProcessor            invokeBeanFactoryPostProcessors(beanFactory);​            // Register bean processors that intercept bean creation.            //处理BeanPostProcessor，按PriorityOrdered、Ordered、其他来收集并实例化和执行            registerBeanPostProcessors(beanFactory);​            // Initialize message source for this context.            //如果有名为messageSource的bean以它作为上下文里的messageSource，否则新建一个DelegatingMessageSource注册单例，并以它作为messageSource            initMessageSource();​            // Initialize event multicaster for this context.            //如果有名为applicationEventMulticaster的bean以它作为上下文的applicationEventMulticaster，否则新建一个SimpleApplicationEventMulticaster注册单例，并以它作为applicationEventMulticaster            initApplicationEventMulticaster();​            // Initialize other special beans in specific context subclasses.            //如果有名为themeSource的bean以它作为web抽象层级的themeSource，否则新建一个            //找容器里的ServletWebServerFactory（这里找到的是tomcatServletWebServerFactory），把它实例化并通过这个工厂创建webServer（这部分还是用spring-boot里的TomcatServletWebServerFactory）            //（！！！后续可以深入一下这里，看一下如何创建一个内嵌的tomcat，以及如何以代码的角度来理解这个tomcat容器）            //创建完毕后，更新对应PropertySource            onRefresh();​            // Check for listener beans and register them.            //拿到applicationEventMulticaster，把之前收录的applicationListeners注册上（注册实例）            //并且从bean容器中找ApplicationListener类别的bean定义，也注册上（注册beanName）            //拿到earlyApplicationEvents，广播事件            registerListeners();​            // Instantiate all remaining (non-lazy-init) singletons.            //看（1.2.4.1）的源码解读，bean实例化部分并没有深入            finishBeanFactoryInitialization(beanFactory);​            // Last step: publish corresponding event.            //清理临时缓存            //如果有名为lifecycleProcessor的bean以它作为上下文的lifecycleProcessor，否则创建一个DefaultLifecycleProcessor，并执行startBeans方法；标记其running=true            //发布一个ContextRefreshedEvent事件            //处理了一个spring.liveBeansView.mbeanDomain相关服务（这里没理解）            //启动webServer            finishRefresh();        }​        catch (BeansException ex) {            if (logger.isWarnEnabled()) {                logger.warn("Exception encountered during context initialization - " +                            "cancelling refresh attempt: " + ex);            }​            // Destroy already created singletons to avoid dangling resources.            destroyBeans();​            // Reset 'active' flag.            cancelRefresh(ex);​            // Propagate exception to caller.            throw ex;        }​        finally {            // Reset common introspection caches in Spring's core, since we            // might not ever need metadata for singleton beans anymore...            resetCommonCaches();        }    }}​

1.2.4.1 AbstractApplicationContext.finishBeanFactoryInitialization

源码如下：

 
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/**
 * Finish the initialization of this context's bean factory, * initializing all remaining singleton beans. */protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {   // Initialize conversion service for this context.   if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) &&         beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) {      beanFactory.setConversionService(
            beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));

   }

​

   // Register a default embedded value resolver if no bean post-processor

   // (such as a PropertyPlaceholderConfigurer bean) registered any before:

   // at this point, primarily for resolution in annotation attribute values.

   if (!beanFactory.hasEmbeddedValueResolver()) {

      beanFactory.addEmbeddedValueResolver(strVal -> getEnvironment().resolvePlaceholders(strVal));

   }

​

   // Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.

    //如果有对应bean定义，【先】创建一个LoadTimeWeaverAware的bean

   String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);

   for (String weaverAwareName : weaverAwareNames) {

      getBean(weaverAwareName);

   }

​

   // Stop using the temporary ClassLoader for type matching.

    //清空临时的类加载器

   beanFactory.setTempClassLoader(null);

​

   // Allow for caching all bean definition metadata, not expecting further changes.

    //这里的意思是冻结beanDefinition，不预期后面还有beanDefinition相关改动

   beanFactory.freezeConfiguration();
​   // Instantiate all remaining (non-lazy-init) singletons.
    //实例化所有有beanDefinition定义但是尚未实例化的bean（具体参见1.2.4.2）

   beanFactory.preInstantiateSingletons();
}

1.2.4.2 DefaultListableBeanFactory.preInstantiateSingletons

大部分的bean实例化就是在这个环节，细节非常复杂，这里并没有深入

 
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@Overridepublic void preInstantiateSingletons() throws BeansException {   if (logger.isTraceEnabled()) {      logger.trace("Pre-instantiating singletons in " + this);   }​   // Iterate over a copy to allow for init methods which in turn register new bean definitions.   // While this may not be part of the regular factory bootstrap, it does otherwise work fine.   List<String> beanNames = new ArrayList<>(this.beanDefinitionNames);​   // Trigger initialization of all non-lazy singleton beans...   for (String beanName : beanNames) {      RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);      if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {         if (isFactoryBean(beanName)) {            Object bean = getBean(FACTORY_BEAN_PREFIX + beanName);            if (bean instanceof FactoryBean) {               final FactoryBean<?> factory = (FactoryBean<?>) bean;               boolean isEagerInit;               if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {                  isEagerInit = AccessController.doPrivileged((PrivilegedAction<Boolean>)                              ((SmartFactoryBean<?>) factory)::isEagerInit,                        getAccessControlContext());               }               else {                  isEagerInit = (factory instanceof SmartFactoryBean &&                        ((SmartFactoryBean<?>) factory).isEagerInit());               }               if (isEagerInit) {                  getBean(beanName);               }            }         }         else {             //这里的实现非常复杂             //创建bean的实际过程（后续专门开章节再深入吧）             //比如bean依赖（dependsOn）、bean实例化时的后置处理（InstantiationAwareBeanPostProcessor）等都是在这里面完成            getBean(beanName);         }      } 
   }

1.2.5 默认的关闭钩子

钩子注册是通过

 
x
 
private void refreshContext(ConfigurableApplicationContext context) {
   refresh(context);   if (this.registerShutdownHook) {      try {         context.registerShutdownHook(); //注册钩子      }      catch (AccessControlException ex) {         // Not allowed in some environments.      }   }}

具体代码为：（只是定义了一个独立线程，在执行结束时才进行调度）

 
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@Override
public void registerShutdownHook() {   if (this.shutdownHook == null) {      // No shutdown hook registered yet.      this.shutdownHook = new Thread(SHUTDOWN_HOOK_THREAD_NAME) {         @Override         public void run() {            synchronized (startupShutdownMonitor) {               doClose();            }         }      };      Runtime.getRuntime().addShutdownHook(this.shutdownHook);   }
}

具体代码如下，注意注释里说的 “Called by both {@code close()} and a JVM shutdown hook, if any.”

 
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/**
 * Actually performs context closing: publishes a ContextClosedEvent and * destroys the singletons in the bean factory of this application context. * <p>Called by both {@code close()} and a JVM shutdown hook, if any. * @see org.springframework.context.event.ContextClosedEvent * @see #destroyBeans() * @see #close() * @see #registerShutdownHook() */protected void doClose() {   // Check whether an actual close attempt is necessary...
   if (this.active.get() && this.closed.compareAndSet(false, true)) { //断点是走不到这里的..
      if (logger.isDebugEnabled()) {         logger.debug("Closing " + this);      }​      LiveBeansView.unregisterApplicationContext(this);​      try {         // Publish shutdown event.     //发布一个ContextClosedEvent事件         publishEvent(new ContextClosedEvent(this));      }      catch (Throwable ex) {         logger.warn("Exception thrown from ApplicationListener handling ContextClosedEvent", ex);      }​      // Stop all Lifecycle beans, to avoid delays during individual destruction.      if (this.lifecycleProcessor != null) {         try {
         //这里貌似是通过生命周期管理停掉所有在执行的bean （TODO 生命周期管理机制是啥?）,并设置lifecycleProcessor.running=false

            this.lifecycleProcessor.onClose();

         }

         catch (Throwable ex) {

            logger.warn("Exception thrown from LifecycleProcessor on context close", ex);

         }

      }

​
      // Destroy all cached singletons in the context's BeanFactory.
      //销毁所有beanFactory中缓存的单例bean

      destroyBeans();

​

  //销毁beanFactory工厂

      // Close the state of this context itself.

      closeBeanFactory();

​

      // Let subclasses do some final clean-up if they wish...

      onClose();
​      // Reset local application listeners to pre-refresh state.      if (this.earlyApplicationListeners != null) {         this.applicationListeners.clear();         this.applicationListeners.addAll(this.earlyApplicationListeners);      }​      // Switch to inactive.      this.active.set(false);   }}

1.3 启动日志分析

1.3.1 虚拟机启动日志打印

日志显示：

 
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Connected to the target VM, address: '127.0.0.1:59163', transport: 'socket'

1.3.2 Banner打印

日志显示：

 
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  .   ____          _            __ _ _
 /\ / ___'_ __ _ _(_)_ __  __ _    ( ( )\___ | '_ | '_| | '_ / _` |     \/  ___)| |_)| | | | | || (_| |  ) ) ) )  '  |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot ::        (v2.2.5.RELEASE)

打印相关代码：

 
Banner printedBanner = printBanner(environment);

堆栈：

 
run:310, SpringApplication (org.springframework.boot)
run:1226, SpringApplication (org.springframework.boot)run:1215, SpringApplication (org.springframework.boot)main:11, DemoApplication (com.example.demo)

1.3.3 环境信息打印

日志显示：

 
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2020-03-20 11:26:35.800  INFO 22748 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on WIN-89EHFNGT2HI with PID 22748 (D:workspace_gwcodedemo-simple-web	argetclasses started by Administrator in D:workspace_gwcodedemo-simple-web)
2020-03-20 11:26:35.803  INFO 22748 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default

打印相关代码：

 
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if (this.logStartupInfo) {
   logStartupInfo(context.getParent() == null);   logStartupProfileInfo(context);
}

堆栈

 
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prepareContext:373, SpringApplication (org.springframework.boot)
run:314, SpringApplication (org.springframework.boot)run:1226, SpringApplication (org.springframework.boot)run:1215, SpringApplication (org.springframework.boot)
main:11, DemoApplication (com.example.demo)

1.3.4 web服务启动日志

 
xxxxxxxxxx
 
2020-03-20 11:33:27.604  INFO 8740 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2020-03-20 11:33:27.661  INFO 8740 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]2020-03-20 11:33:27.663  INFO 8740 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.31]2020-03-20 11:33:28.328  INFO 8740 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext2020-03-20 11:33:28.329  INFO 8740 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 15341 ms

打印相关方法：

createWebServer();

堆栈：

 
onRefresh:153, ServletWebServerApplicationContext (org.springframework.boot.web.servlet.context)
refresh:544, AbstractApplicationContext (org.springframework.context.support)refresh:141, ServletWebServerApplicationContext (org.springframework.boot.web.servlet.context)refresh:747, SpringApplication (org.springframework.boot)refreshContext:397, SpringApplication (org.springframework.boot)run:315, SpringApplication (org.springframework.boot)run:1226, SpringApplication (org.springframework.boot)run:1215, SpringApplication (org.springframework.boot)main:11, DemoApplication (com.example.demo)

1.3.5 实例化相关信息打印

这里只是默认spring-boot-web的一个实例的打印

日志显示：

 
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2020-03-20 11:36:29.536  INFO 21876 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'

打印相关方法：

 
x
 
if (logger.isInfoEnabled()) {   logger.info("Initializing ExecutorService" + (this.beanName != null ? " '" + this.beanName + "'" : "")); 
}

堆栈：

 
xxxxxxxxxx
 
initialize:181, ExecutorConfigurationSupport (org.springframework.scheduling.concurrent)
afterPropertiesSet:173, ExecutorConfigurationSupport (org.springframework.scheduling.concurrent)invokeInitMethods:1855, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)initializeBean:1792, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)doCreateBean:595, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)createBean:517, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)lambda$doGetBean$0:323, AbstractBeanFactory (org.springframework.beans.factory.support)getObject:-1, 124734309 (org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$143)getSingleton:222, DefaultSingletonBeanRegistry (org.springframework.beans.factory.support)doGetBean:321, AbstractBeanFactory (org.springframework.beans.factory.support)getBean:202, AbstractBeanFactory (org.springframework.beans.factory.support)configureAsyncSupport:211, WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter (org.springframework.boot.autoconfigure.web.servlet)configureAsyncSupport:67, WebMvcConfigurerComposite (org.springframework.web.servlet.config.annotation)configureAsyncSupport:68, DelegatingWebMvcConfiguration (org.springframework.web.servlet.config.annotation)requestMappingHandlerAdapter:626, WebMvcConfigurationSupport (org.springframework.web.servlet.config.annotation)requestMappingHandlerAdapter:369, WebMvcAutoConfiguration$EnableWebMvcConfiguration (org.springframework.boot.autoconfigure.web.servlet)invoke0:-1, NativeMethodAccessorImpl (sun.reflect)invoke:62, NativeMethodAccessorImpl (sun.reflect)invoke:43, DelegatingMethodAccessorImpl (sun.reflect)invoke:498, Method (java.lang.reflect)instantiate:154, SimpleInstantiationStrategy (org.springframework.beans.factory.support)instantiate:651, ConstructorResolver (org.springframework.beans.factory.support)instantiateUsingFactoryMethod:636, ConstructorResolver (org.springframework.beans.factory.support)instantiateUsingFactoryMethod:1338, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)createBeanInstance:1177, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)doCreateBean:557, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
createBean:517, AbstractAutowireCapableBeanFactory (org.springframework.beans.factory.support)
lambda$doGetBean$0:323, AbstractBeanFactory (org.springframework.beans.factory.support)getObject:-1, 124734309 (org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$143)getSingleton:222, DefaultSingletonBeanRegistry (org.springframework.beans.factory.support)doGetBean:321, AbstractBeanFactory (org.springframework.beans.factory.support)getBean:202, AbstractBeanFactory (org.springframework.beans.factory.support)preInstantiateSingletons:879, DefaultListableBeanFactory (org.springframework.beans.factory.support)finishBeanFactoryInitialization:878, AbstractApplicationContext (org.springframework.context.support)refresh:550, AbstractApplicationContext (org.springframework.context.support)refresh:141, ServletWebServerApplicationContext (org.springframework.boot.web.servlet.context)refresh:747, SpringApplication (org.springframework.boot)refreshContext:397, SpringApplication (org.springframework.boot)run:315, SpringApplication (org.springframework.boot)run:1226, SpringApplication (org.springframework.boot)run:1215, SpringApplication (org.springframework.boot)
main:11, DemoApplication (com.example.demo)

1.3.6 web启动打印

日志显示：

 
xxxxxxxxxx
 
2020-03-20 11:37:38.186  INFO 21876 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''

1.3.7 启动成功日志

日志显示：

 
xxxxxxxxxx
 
2020-03-20 11:38:06.446  INFO 21876 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 168.106 seconds (JVM running for 178.556)

SpringBoot启动关键点解析 及启动日志追溯

目录

1 SpringBoot启动关键点解析

1.1 new SpringApplication(primarySources)部分

1.2 run(args)部分

1.2.1 ConfigurableEnvironment提供的服务（关注的信息）

1.2.2 ConfigurableApplicationContext

1.2.3 SpringApplication.prepareContext

1.2.4 SpringApplication.refreshContext

1.2.4.1 AbstractApplicationContext.finishBeanFactoryInitialization

1.2.4.2 DefaultListableBeanFactory.preInstantiateSingletons

1.2.5 默认的关闭钩子

1.3 启动日志分析

1.3.1 虚拟机启动日志打印

1.3.2 Banner打印

1.3.3 环境信息打印

1.3.4 web服务启动日志

1.3.5 实例化相关信息打印

1.3.6 web启动打印

1.3.7 启动成功日志

SpringBoot启动关键点解析及启动日志追溯