springboot啓動源碼解析

/** *SpringApplication */ //構造器初始化 public SpringApplication(ResourceLoader resourceLoader, Class... primarySources) { this.sources = new LinkedHashSet(); //橫幅模式 OFF,CONSOLE,LOG; this.bannerMode = Mode.CONSOLE; this.logStartupInfo = true; this.addCommandLineProperties = true; this.addConversionService = true; this.headless = true; this.registerShutdownHook = true; this.additionalProfiles = new HashSet(); this.isCustomEnvironment = false; this.resourceLoader = resourceLoader; Assert.notNull(primarySources, "PrimarySources must not be null"); this.primarySources = new LinkedHashSet(Arrays.asList(primarySources)); //應用類型NONE,SERVLET,REACTIVE;存在DispatcherHandler，不存在DispatcherServlet，ServletContainer，則爲REACTIVE //不存在javax.servlet.Servlet", "org.springframework.web.context.ConfigurableWebApplicationContext，則爲NONE，則爲SERVLET this.webApplicationType = WebApplicationType.deduceFromClasspath(); //spring.factories文件中org.springframework.context.ApplicationContextInitializer=\ //org.springframework.boot.context.ConfigurationWarningsApplicationContextInitializer,\ //org.springframework.boot.context.ContextIdApplicationContextInitializer,\ //org.springframework.boot.context.config.DelegatingApplicationContextInitializer,\ //org.springframework.boot.web.context.ServerPortInfoApplicationContextInitializer this.setInitializers(this.getSpringFactoriesInstances(ApplicationContextInitializer.class)); //org.springframework.context.ApplicationListener=\ //org.springframework.boot.ClearCachesApplicationListener,\ //org.springframework.boot.builder.ParentContextCloserApplicationListener,\ //org.springframework.boot.context.FileEncodingApplicationListener,\ //org.springframework.boot.context.config.AnsiOutputApplicationListener,\ //org.springframework.boot.context.config.ConfigFileApplicationListener,\ //org.springframework.boot.context.config.DelegatingApplicationListener,\ //org.springframework.boot.context.logging.ClasspathLoggingApplicationListener,\ //org.springframework.boot.context.logging.LoggingApplicationListener,\ //org.springframework.boot.liquibase.LiquibaseServiceLocatorApplicationListener 進行初始化 this.setListeners(this.getSpringFactoriesInstances(ApplicationListener.class)); //推論出主類main this.mainApplicationClass = this.deduceMainApplicationClass(); } //核心開始運行 public ConfigurableApplicationContext run(String... args) { //秒錶，用於記錄啓動時間，記錄每個任務 的時間， StopWatch stopWatch = new StopWatch(); stopWatch.start(); //spring應用上下文，spring容器 ConfigurableApplicationContext context = null; //自定義SpringApplication啓動錯誤的回調接口 Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList(); //java.awt.headless模式 默認爲true開啓 this.configureHeadlessProperty(); //開啓監聽 //org.springframework.boot.SpringApplicationRunListener=\ //org.springframework.boot.context.event.EventPublishingRunListener SpringApplicationRunListeners listeners = this.getRunListeners(args); // listeners.starting(); Collection exceptionReporters; try { //參數封裝，在命令行下啓動應用帶的參數，如--server.port ApplicationArguments applicationArguments = new DefaultApplicationArguments(args); //環境準備 1.加載外部化配置的資源到environment 2.觸發ApplicationEnvironmentPreparedEvent事件 ConfigurableEnvironment environment = this.prepareEnvironment(listeners, applicationArguments); //配置系統屬性spring.beaninfo.ignore this.configureIgnoreBeanInfo(environment); //打印橫幅 Banner printedBanner = this.printBanner(environment); //創建ApplicationContext 根據webApplicationType //SERVLET: // contextClass = Class.forName("org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext"); //REACTIVE: // contextClass = Class.forName("org.springframework.boot.web.reactive.context.AnnotationConfigReactiveWebServerApplicationContext"); // default: // contextClass = Class.forName("org.springframework.context.annotation.AnnotationConfigApplicationContext"); /** *AnnotationConfigServletWebServerApplicationContext層級關係-》ServletWebServerApplicationContext-》GenericWebApplicationContext *-》GenericApplicationContext-》AbstractApplicationContext */ //部分屬性：reader、scanner、beanFactory進行了實例化 context = this.createApplicationContext(); //實例化 用來支持報告關於啓動的錯誤 //# Error Reporters //org.springframework.boot.SpringBootExceptionReporter=\ //org.springframework.boot.diagnostics.FailureAnalyzers exceptionReporters = this.getSpringFactoriesInstances(SpringBootExceptionReporter.class, new Class[]{ConfigurableApplicationContext.class}, context); //ApplicationContext準備 加載 this.prepareContext(context, environment, listeners, applicationArguments, printedBanner); //核心： this.refreshContext(context); this.afterRefresh(context, applicationArguments); stopWatch.stop(); if (this.logStartupInfo) { (new StartupInfoLogger(this.mainApplicationClass)).logStarted(this.getApplicationLog(), stopWatch); } listeners.started(context); this.callRunners(context, applicationArguments); } catch (Throwable var10) { this.handleRunFailure(context, var10, exceptionReporters, listeners); throw new IllegalStateException(var10); } try { listeners.running(context); return context; } catch (Throwable var9) { this.handleRunFailure(context, var9, exceptionReporters, (SpringApplicationRunListeners)null); throw new IllegalStateException(var9); } } //環境準備 private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments) { //創建環境 SERVLET StandardServletEnvironment； REACTIVE StandardReactiveWebEnvironment； StandardEnvironment ConfigurableEnvironment environment = this.getOrCreateEnvironment(); this.configureEnvironment((ConfigurableEnvironment)environment, applicationArguments.getSourceArgs()); listeners.environmentPrepared((ConfigurableEnvironment)environment); this.bindToSpringApplication((ConfigurableEnvironment)environment); if (!this.isCustomEnvironment) { environment = (new EnvironmentConverter(this.getClassLoader())).convertEnvironmentIfNecessary((ConfigurableEnvironment)environment, this.deduceEnvironmentClass()); } ConfigurationPropertySources.attach((Environment)environment); return (ConfigurableEnvironment)environment; } /** *AbstractApplicationContext */ //刷新 public void refresh() throws BeansException, IllegalStateException { Object var1 = this.startupShutdownMonitor; synchronized(this.startupShutdownMonitor) { //刷新前準備 校驗 this.prepareRefresh(); //獲取DefaultListableBeanFactory實例 ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory(); //beanFactory加載配置 this.prepareBeanFactory(beanFactory); try { //beanFactory後置處理，重寫ApplicationContext的postProcessBeanFactory方法 this.postProcessBeanFactory(beanFactory); //核心： this.invokeBeanFactoryPostProcessors(beanFactory); //註冊BeanPostProcessor this.registerBeanPostProcessors(beanFactory); this.initMessageSource(); this.initApplicationEventMulticaster(); this.onRefresh(); this.registerListeners(); this.finishBeanFactoryInitialization(beanFactory); this.finishRefresh(); } catch (BeansException var9) { if (this.logger.isWarnEnabled()) { this.logger.warn("Exception encountered during context initialization - cancelling refresh attempt: " + var9); } this.destroyBeans(); this.cancelRefresh(var9); throw var9; } finally { this.resetCommonCaches(); } } }