public ConfigurableApplicationContext run(String... args) {

   StopWatch stopWatch = new StopWatch();

   stopWatch.start();

   ConfigurableApplicationContext context = null;

   FailureAnalyzers analyzers = null;

   configureHeadlessProperty();

   //获取SpringApplicationRunListeners；从类路径下META-INF/spring.factories

   SpringApplicationRunListeners listeners = getRunListeners(args);

    //回调所有的获取SpringApplicationRunListener.starting()方法

   listeners.starting();

   try {

       //封装命令行参数

      ApplicationArguments applicationArguments = new DefaultApplicationArguments(

            args);

      //准备环境

      ConfigurableEnvironment environment = prepareEnvironment(listeners,

            applicationArguments);

            //创建环境完成后回调SpringApplicationRunListener.environmentPrepared()；表示环境准备完成

      Banner printedBanner = printBanner(environment);

       //创建ApplicationContext；决定创建web的ioc还是普通的ioc

      context = createApplicationContext();

       //异常报告

      analyzers = new FailureAnalyzers(context);

       //准备上下文环境;将environment保存到ioc中；而且applyInitializers()；

       //applyInitializers()：回调之前保存的所有的ApplicationContextInitializer的initialize方法

       //回调所有的SpringApplicationRunListener的contextPrepared()；

       //prepareContext运行完成以后回调所有的 SpringApplicationRunListener的contextLoaded（）；

      prepareContext(context, environment, listeners, applicationArguments,

            printedBanner);

       //s刷新容器；ioc容器初始化（如果是web应用还会创建嵌入式的Tomcat）；Spring注解版

       //扫描，创建，加载所有组件的地方；（配置类，组件，自动配置）

      refreshContext(context);

       //从ioc容器中获取所有的ApplicationRunner和CommandLineRunner进行回调

       //ApplicationRunner先回调，CommandLineRunner再回调

      afterRefresh(context, applicationArguments);

       //所有的SpringApplicationRunListener回调finished方法

      listeners.finished(context, null);

      stopWatch.stop();

      if (this.logStartupInfo) {

         new StartupInfoLogger(this.mainApplicationClass)

               .logStarted(getApplicationLog(), stopWatch);

      }

       //整个SpringBoot应用启动完成以后返回启动的ioc容器；

      return context;

   }

   catch (Throwable ex) {

      handleRunFailure(context, listeners, analyzers, ex);

      throw new IllegalStateException(ex);

   }

}