啟動流程分析

SpringApplication.run(App.class, args);return new SpringApplication(primarySources).run(args);

創建 SpringApplication

SpringApplication(primarySources):this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
//這個推斷流程 001 篇 分析webServer里有詳情 web應用返回WebApplicationType.SERVLET
this.webApplicationType = WebApplicationType.deduceFromClasspath();
//獲取Factories中配置的 BootstrapRegistryInitializer
this.bootstrapRegistryInitializers = new ArrayList<>(getSpringFactoriesInstances(BootstrapRegistryInitializer.class));
this.initializers = getSpringFactoriesInstances(ApplicationContextInitializer.class);
this.listeners = getSpringFactoriesInstances(ApplicationListener.class));
//推斷main方法所在的Class
this.mainApplicationClass = deduceMainApplicationClass();

啟動 run(String… args)

//獲取Factories中配置的 SpringApplicationRunListener 并執行其 starting()
SpringApplicationRunListeners listeners = getSpringFactoriesInstances(SpringApplicationRunListener.class, types, this, args).forEach(listener.starting(bootstrapContext))
//封裝 args：這里會讀取執行jar的時候添加的以 '--' 開頭的 kay=value
ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
//讀取配置 包括：系統，JVM,ServletContext,properties,yaml配置
//全部設置到 environment 中
ConfigurableEnvironment environment = prepareEnvironment(listeners, bootstrapContext, applicationArguments);
//這一步我查資料應該是忽略Java解析BeanInfo的緩存 因為Spring使用的是ASM技術
configureIgnoreBeanInfo(environment);
//打印banner并返回
Banner printedBanner = printBanner(environment);
//根據類型返回上下文 001 有詳細分析 AnnotationConfigServletWebServerApplicationContext
context = createApplicationContext();
context.applicationStartup = applicationStartup;
//利用ApplicationContextInitializer初始化Spring 上下文
//發布ApplicationContextInitializedEvent
//注冊primarySources = run() 傳入的配置類列表
//發布ApplicationContextPreparedEvent
prepareContext(bootstrapContext, context, environment, listeners, applicationArguments, printedBanner);
//調用refresh(context) 這一步就是執行Spring bean創建的邏輯了
refreshContext(context);
//這一步是空的 給子類一個實現的機會
afterRefresh(context, applicationArguments);
//遍歷執行之前 listeners started()
listeners.started(context, timeTakenToStartup);
//執行 ApplicationRunner.run(args);
//執行 CommandLineRunner.run(args.getSourceArgs());
//兩個執行器只有 入參的區別 一個是解析之后的對象，一個是字符串
callRunners(context, applicationArguments);
//遍歷執行之前 listeners ready()
listeners.ready(context, timeTakenToReady);