SpringApplication.run(DemoApplication.class, args); -> [ConfigurableApplicationContext] ConfigurableApplicationContext.run(new Class[]{primarySource},  args) -> new SpringApplication(primarySources)).run(args) -> 打开stopWatch 配置上下文  配置文件  类监听器 新建类  类工厂新建类实例 prepareContext refreshContext afterRefresh 关闭stopWatch

创建bean + 解决循环依赖问题：

AbstractBeanFactory getBean(name) ->  doGetBean(name, (Class)null, (Object[])null, false) -> createBean ->doCreateBean ->createBeanInstance ->populateBean