Springboot自动扫描包路径来龙去脉示例详解

public ConfigurableApplicationContext run(String... args) {
		StopWatch stopWatch = new StopWatch();
		stopWatch.start();
		ConfigurableApplicationContext cOntext= null;
		Collection exceptiOnReporters= new ArrayList<>();
		configureHeadlessProperty();
		SpringApplicationRunListeners listeners = getRunListeners(args);
		listeners.starting();
		try {
			ApplicationArguments applicatiOnArguments= new DefaultApplicationArguments(args);
			ConfigurableEnvironment envirOnment= prepareEnvironment(listeners, applicationArguments);
			configureIgnoreBeanInfo(environment);
			Banner printedBanner = printBanner(environment);
			//@A
			cOntext= createApplicationContext();
			exceptiOnReporters= getSpringFactoriesInstances(SpringBootExceptionReporter.class,
					new Class[] { ConfigurableApplicationContext.class }, context);
			//@B
			prepareContext(context, environment, listeners, applicationArguments, printedBanner);
			//@C
			refreshContext(context);
			afterRefresh(context, applicationArguments);
			stopWatch.stop();
			if (this.logStartupInfo) {
				new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
			}
			listeners.started(context);
			callRunners(context, applicationArguments);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, exceptionReporters, listeners);
			throw new IllegalStateException(ex);
		}

		try {
			listeners.running(context);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, exceptionReporters, null);
			throw new IllegalStateException(ex);
		}
		return context;
	}

org.springframework.boot.SpringApplication#run(java.lang.Class<&＃63;>, java.lang.String...)
->org.springframework.boot.SpringApplication#run(java.lang.String...)
->org.springframework.boot.SpringApplication#createApplicationContext 
//对应上面@A标注的地方
//后续会初始化一个org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext对象，在构造方法里会执行一系列的逻辑
->org.springframework.context.annotation.AnnotatedBeanDefinitionReader#AnnotatedBeanDefinitionReader(org.springframework.beans.factory.support.BeanDefinitionRegistry)
->org.springframework.context.annotation.AnnotatedBeanDefinitionReader#AnnotatedBeanDefinitionReader(org.springframework.beans.factory.support.BeanDefinitionRegistry, org.springframework.core.env.Environment)
->org.springframework.context.annotation.AnnotationConfigUtils#registerAnnotationConfigProcessors(org.springframework.beans.factory.support.BeanDefinitionRegistry)
->org.springframework.context.annotation.AnnotationConfigUtils#registerAnnotationConfigProcessors(org.springframework.beans.factory.support.BeanDefinitionRegistry, java.lang.Object)

//这个方法会注入5个bean定义：
1. ConfigurationClassPostProcessor.class
2. AutowiredAnnotationBeanPostProcessor.class
3. CommonAnnotationBeanPostProcessor.class
4. EventListenerMethodProcessor.class
5. DefaultEventListenerFactory.class

org.springframework.boot.SpringApplication#run(java.lang.String...)
org.springframework.boot.SpringApplication#prepareContext //对应上面代码标注 @B 的地方
org.springframework.boot.SpringApplication#load
org.springframework.boot.BeanDefinitionLoader#load(java.lang.Object)
org.springframework.boot.BeanDefinitionLoader#load(java.lang.Class<&＃63;>)
org.springframework.context.annotation.AnnotatedBeanDefinitionReader#register
org.springframework.context.annotation.AnnotatedBeanDefinitionReader#registerBean(java.lang.Class<&＃63;>)
org.springframework.context.annotation.AnnotatedBeanDefinitionReader#doRegisterBean

//里面一段代码 如下：
AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(beanClass);
//从这个方法里可以看出，启动类被包装成了 AnnotatedGenericBeanDefinition（实现了AnnotatedBeanDefinition接口，这很重要）