springBoot

2021-08-21 22:30:37   12  举报

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springBoot启动流程

SpringBoot

java

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作者其他创作

大纲/内容

//读取项目的配置文件，并保存到environment中ConfigurableEnvironment environment

finishRefresh()；

告诉子类刷新内部BeanFactoryobtainFreshBeanFactory()

ConfigurableApplicationContext

onRefresh();

getRunListeners(args)

getBean(beanName)

//调用BeanFactoryPostProcessor后置处理器，其中有一个后置处理器ConfigurationClassPostProcessor，它将由启动类开始，递归解析项目中配置的bean，将bean解析为BeanDefinition对象，放置到beanDefinitionMap中

refreshContext(context);

//启动web容器（tomcat容器）getLifecycleProcessor().onRefresh();

context = createApplicationContext();

new SpringApplication(primarySources)

ConfigurableApplicationContext run(String... args)

ConfigurationClassPostProcessor

//读取resources/META-INF/spring.factories配置文件中配置的SpringApplicationRunListener.class类型的事件发布器，由它发布的事件会被ApplicationListener监听到org.springframework.boot.SpringApplicationRunListener=\\org.springframework.boot.context.event.EventPublishingRunListener

SpringApplication

ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

SpringApplicationRunListeners listeners = getRunListeners(args);

parser.parse(candidates);

new SpringApplication(primarySources).run(args);

//遍历beanDefinitionMap，实例并初始化单例Bean

我们的应用是WebApplicationType.SERVLET类型，创建的是AnnotationConfigServletWebServerApplicationContext类型的实例

finishBeanFactoryInitialization(beanFactory);

//创建web服务器，默认是tomcat容器createWebServer()

createApplicationContext()

invokeBeanFactoryPostProcessors(beanFactory);

ConfigurableListableBeanFactory

//推断应用的类型，一般是WebApplicationType.SERVLET类型this.webApplicationType = WebApplicationType.deduceFromClasspath();//读取resources/META-INF/spring.factories配置文件中配置的ApplicationContextInitializer.class类型的容器上下文初始化器setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));//读取resources/META-INF/spring.factories配置文件中配置的ApplicationListener.class类型的应用监听器setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));