springboot2.2.x源码分析

获取监听器SpringApplicationgetRunListeners()

ConfigurationClassParser.DeferredImportSelectorGroupingHandlerprocessGroupImports

执行监听器启动方法SpringApplicationlisteners.starting()

执行监听器上下文加载方法SpringApplicationlisteners.contextLoaded()

ConfigurationClassParser.DeferredImportSelectorHandlerprocess

过滤掉重复配置的自动配置类以及配置在exclude和excludeName中的类

ConfigurationClassParser.DeferredImportSelectorGroupinggetImports

AutoConfigurationImportSelector.AutoConfigurationGroupprocess

ConfigurationClassPostProcessor processConfigBeanDefinitions

获取META-INF/spring.factories下所有的自动配置类AutoConfigurationImportSelectorgetCandidateConfigurations

每个线程获取@OnClassConditional中配置的类，并使用ClassLoader.loadClass()或者Class.forName()尝试加载，如果加载不了则不满足条件，否则满足条件

Springboot启动流程

执行过滤filter.match()

三个注解循环遍历，任何一个条件不满足则不会自动配置以@OnClassConditional为例执行getOutcomes()刷选

反射创建容器AnnotationConfigServletWebServerApplicationContext

执行监听器上下文已运行方法SpringApplicationlisteners.started()

执行监听器准备环境方法SpringApplicationlisteners.environmentPrepared()

AnnotationConfigServletWebServerApplicationContext在初始化时注入ConfigurationClassPostProcessor此类是自动配置的入口

springr容器刷新SpringApplicationrefreshContext()

启动SpringApplicationrun()

SpringBoot自动配置流程

ConfigurationClassParserparse

创建IOC容器SpringApplicationcreateApplicationContext()

准备上线文SpringApplicationprepareContext()

AutoConfigurationImportSelectorgetAutoConfigurationEntry

注入启动类SpringApplicationload()

打印bannerSpringApplicationprintBanner()

容器刷新时执行ConfigurationClassPostProcessor postProcessBeanDefinitionRegistry

扩展模版方法SpringApplicationafterRefresh()

准备环境SpringApplicationprepareEnvironment()

基于ApplicationRunner和CommandLineRunner接口的扩展callRunners()

执行监听器上下文已启动方法SpringApplicationlisteners.started()

过滤掉不符合条件的自动配置类

设置需要忽略的beanSpringApplicationconfigureIgnoreBeanInfo()

执行初始化器applyInitializersinitialize()

执行监听器上下文准备方法SpringApplicationlisteners.contextPrepared()

获取过滤条件，默认有三个条件@OnBeanConditional、@OnClassConditional、@OnWebApplicationConditionalgetAutoConfigurationImportFilters()

处理器大于1个时用两个线程处理每个线程处理一半，处理完后合并resolveOutcomesThreaded()