5）、嵌入式Servlet容器啟動原理；

什么時候創(chuàng)建嵌入式的Servlet容器工廠？什么時候獲取嵌入式的Servlet容器并啟動Tomcat；

獲取嵌入式的Servlet容器工廠：

1）、SpringBoot應(yīng)用啟動運行run方法

2）、refreshContext(context);SpringBoot刷新IOC容器【創(chuàng)建IOC容器對象，并初始化容器，創(chuàng)建容器中的每一個組件】；如果是web應(yīng)用創(chuàng)建AnnotationConfigEmbeddedWebApplicationContext，否則：AnnotationConfigApplicationContext

3）、refresh(context);刷新剛才創(chuàng)建好的ioc容器；

public void refresh() throws BeansException, IllegalStateException {
   synchronized (this.startupShutdownMonitor) {
      // Prepare this context for refreshing.
      prepareRefresh();

      // Tell the subclass to refresh the internal bean factory.
      ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

      // Prepare the bean factory for use in this context.
      prepareBeanFactory(beanFactory);

      try {
         // Allows post-processing of the bean factory in context subclasses.
         postProcessBeanFactory(beanFactory);

         // Invoke factory processors registered as beans in the context.
         invokeBeanFactoryPostProcessors(beanFactory);

         // Register bean processors that intercept bean creation.
         registerBeanPostProcessors(beanFactory);

         // Initialize message source for this context.
         initMessageSource();

         // Initialize event multicaster for this context.
         initApplicationEventMulticaster();

         // Initialize other special beans in specific context subclasses.
         onRefresh();

         // Check for listener beans and register them.
         registerListeners();

         // Instantiate all remaining (non-lazy-init) singletons.
         finishBeanFactoryInitialization(beanFactory);

         // Last step: publish corresponding event.
         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();
      }
   }
}

4）、 onRefresh(); web的ioc容器重寫了onRefresh方法

5）、webioc容器會創(chuàng)建嵌入式的Servlet容器；createEmbeddedServletContainer();

6）、獲取嵌入式的Servlet容器工廠：

EmbeddedServletContainerFactory containerFactory = getEmbeddedServletContainerFactory();

? 從ioc容器中獲取EmbeddedServletContainerFactory 組件；TomcatEmbeddedServletContainerFactory創(chuàng)建對象，后置處理器一看是這個對象，就獲取所有的定制器來先定制Servlet容器的相關(guān)配置；

7）、使用容器工廠獲取嵌入式的Servlet容器：this.embeddedServletContainer = containerFactory .getEmbeddedServletContainer(getSelfInitializer());

8）、嵌入式的Servlet容器創(chuàng)建對象并啟動Servlet容器；

先啟動嵌入式的Servlet容器，再將ioc容器中剩下沒有創(chuàng)建出的對象獲取出來；

==IOC容器啟動創(chuàng)建嵌入式的Servlet容器==