1、初始化

2、run

2.1、StopWatch

2.2、getRunListeners().starting()

2.3、prepareEnvironment

2.4、printBanner

2.5、createApplicationContext()

2.6、refreshContext(context)

2.7、refreshContext(context)

2.8、afterRefresh(context, applicationArguments)

2.9、listeners.finished(context, null)

附录-run

public ConfigurableApplicationContext run(String... args) {
  // 2.1、StopWatch 
  StopWatch stopWatch = new StopWatch();
  stopWatch.start();
  ConfigurableApplicationContext context = null;
  FailureAnalyzers analyzers = null;
  // 2.2
  configureHeadlessProperty();
  // 2.3 getRunListeners().starting()
  SpringApplicationRunListeners listeners = getRunListeners(args);
  listeners.starting();
  try {
    // 2.4、prepareEnvironment
    ApplicationArguments applicationArguments = new DefaultApplicationArguments(
        args);
    ConfigurableEnvironment environment = prepareEnvironment(listeners,
        applicationArguments);
    // 2.5 打印 Spring Boot logo
    Banner printedBanner = printBanner(environment);
    // 2.6 创建ApplicationContext
    context = createApplicationContext();
    analyzers = new FailureAnalyzers(context);
    // 2.7  
    prepareContext(context, environment, listeners, applicationArguments,
        printedBanner);
    // 2.8 
    refreshContext(context);
    // 2.9  
    afterRefresh(context, applicationArguments);
    // 2.10 
    listeners.finished(context, null);
    stopWatch.stop();
    if (this.logStartupInfo) {
      new StartupInfoLogger(this.mainApplicationClass)
          .logStarted(getApplicationLog(), stopWatch);
    }
    return context;
  }
  catch (Throwable ex) {
    handleRunFailure(context, listeners, analyzers, ex);
    throw new IllegalStateException(ex);
  }
}