SpringBoot-启动应用及回调监听

主类Main方法

public static void main(String[] args) {
	SpringApplication.run(SpringBootRunApplication.class, args);
}

创建SpringApplication对象

public static ConfigurableApplicationContext run(Class<?>[] primarySources, String[] args) {
	return (new SpringApplication(primarySources)).run(args);
}　　

　　构造器

public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
	this.sources = new LinkedHashSet();
	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.lazyInitialization = false;
	this.resourceLoader = resourceLoader;
	Assert.notNull(primarySources, "PrimarySources must not be null");
	this.primarySources = new LinkedHashSet(Arrays.asList(primarySources));
	this.webApplicationType = WebApplicationType.deduceFromClasspath();
	this.setInitializers(this.getSpringFactoriesInstances(ApplicationContextInitializer.class));
	this.setListeners(this.getSpringFactoriesInstances(ApplicationListener.class));
	this.mainApplicationClass = this.deduceMainApplicationClass();
}

　　ApplicationContextInitializer&ApplicationListener

　　　　读取META-INF/spring.factories文件中的类　

this.setInitializers(this.getSpringFactoriesInstances(ApplicationContextInitializer.class));
this.setListeners(this.getSpringFactoriesInstances(ApplicationListener.class));

执行run方法　

public ConfigurableApplicationContext run(String... args) {
	StopWatch stopWatch = new StopWatch();
	stopWatch.start();
	// IOC容器
	ConfigurableApplicationContext context = null;
	Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList();
	this.configureHeadlessProperty();
	// 读取META-INF/spring.factories文件获得SpringApplicationRunListener的实现类集合
	SpringApplicationRunListeners listeners = this.getRunListeners(args);
	// 监听开始，回调所有SpringApplicationRunListener的starting()方法
	listeners.starting();

	Collection exceptionReporters;
	try {
		ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
		// 监听配置环境准备好了，回调所有SpringApplicationRunListener的environmentPrepared()方法
		ConfigurableEnvironment environment = this.prepareEnvironment(listeners, applicationArguments);
		this.configureIgnoreBeanInfo(environment);
		Banner printedBanner = this.printBanner(environment);
		// 创建IOC容器
		context = this.createApplicationContext();
		exceptionReporters = this.getSpringFactoriesInstances(SpringBootExceptionReporter.class, new Class[]{ConfigurableApplicationContext.class}, context);
		// 回调ApplicationContextInitializer的initialize()方法，回调SpringApplicationRunListener的contextPrepared()方法
		// 回调SpringApplicationRunListener的contextLoaded()方法
		this.prepareContext(context, environment, listeners, applicationArguments, printedBanner);
		// 刷新IOC容器，注入组件
		this.refreshContext(context);
		this.afterRefresh(context, applicationArguments);
		stopWatch.stop();
		if (this.logStartupInfo) {
			(new StartupInfoLogger(this.mainApplicationClass)).logStarted(this.getApplicationLog(), stopWatch);
		}
		// 回调SpringApplicationRunListener的started()方法
		listeners.started(context);
		// 从IOC容器中获得ApplicationRunner、CommandLineRunner的所有组件，回调ApplicationRunner、CommandLineRunner的run()方法
		this.callRunners(context, applicationArguments);
	} catch (Throwable var10) {
		this.handleRunFailure(context, var10, exceptionReporters, listeners);
		throw new IllegalStateException(var10);
	}

	try {
		// 回调SpringApplicationRunListener的running()方法
		listeners.running(context);
		return context;
	} catch (Throwable var9) {
		this.handleRunFailure(context, var9, exceptionReporters, (SpringApplicationRunListeners)null);
		throw new IllegalStateException(var9);
	}
}