@EnableAsync
@EnableScheduling
@EnableTransactionManagement
@EnableConfigurationProperties
@EnableCaching
@MapperScan(value = {"com.study.springbootplus.**.mapper"})
@SpringBootApplication
public class SpringBootPlusApplication {

  public static void main(String[] args) {
    ConfigurableApplicationContext context = SpringApplication.run(SpringBootPlusApplication.class, args);
  }

}

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

	public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
		this.resourceLoader = resourceLoader;
		Assert.notNull(primarySources, "PrimarySources must not be null");
		// main方法中的args參數(shù)，可接收命令行啟動(dòng)時(shí)添加的參數(shù)
		this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
		// 確認(rèn)spring容器類型
		this.webApplicationType = WebApplicationType.deduceFromClasspath();
		//加載ApplicationContextInitializer類,ApplicationContext初始化類
		setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
		//加載ApplicationListener類,監(jiān)聽(tīng)類
		setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
		//獲取main方法所在類
		this.mainApplicationClass = deduceMainApplicationClass();
	}

	private Class<?> deduceMainApplicationClass() {
		try {
			StackTraceElement[] stackTrace = new RuntimeException().getStackTrace();
			for (StackTraceElement stackTraceElement : stackTrace) {
				if ("main".equals(stackTraceElement.getMethodName())) {
					return Class.forName(stackTraceElement.getClassName());
				}
			}
		}
		catch (ClassNotFoundException ex) {
			// Swallow and continue
		}
		return null;
	}

public ConfigurableApplicationContext run(String... args) {
//計(jì)時(shí)
		StopWatch stopWatch = new StopWatch();
		stopWatch.start();
		//spring容器
		ConfigurableApplicationContext context = null;
		//錯(cuò)誤回調(diào)
		Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();
		//設(shè)置一些系統(tǒng)屬性
		configureHeadlessProperty();
		//獲取啟動(dòng)時(shí)監(jiān)聽(tīng)器
		SpringApplicationRunListeners listeners = getRunListeners(args);
		//啟動(dòng)監(jiān)聽(tīng)器
		listeners.starting();
		try {
		//獲取一些啟動(dòng)參數(shù)
			ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
			//創(chuàng)建運(yùn)行環(huán)境environment
			ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
			//設(shè)置一些系統(tǒng)參數(shù)
			configureIgnoreBeanInfo(environment);
			//打印banner
			Banner printedBanner = printBanner(environment);
			//創(chuàng)建spring容器
			context = createApplicationContext();
			//獲取異常報(bào)告,回調(diào)
			exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,
					new Class[] { ConfigurableApplicationContext.class }, context);
					//準(zhǔn)備容器
			prepareContext(context, environment, listeners, applicationArguments, printedBanner);
			//刷新容器
			refreshContext(context);
			//spring容器后置處理
			afterRefresh(context, applicationArguments);
			//計(jì)時(shí)終止
			stopWatch.stop();
			if (this.logStartupInfo) {
				new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
			}
			//結(jié)束通知
			listeners.started(context);
			//執(zhí)行runner
			callRunners(context, applicationArguments);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, exceptionReporters, listeners);
			throw new IllegalStateException(ex);
		}

		try {
		//spring容器就緒通知
			listeners.running(context);
		}
		catch (Throwable ex) {
			handleRunFailure(context, ex, exceptionReporters, null);
			throw new IllegalStateException(ex);
		}
		//返回容器
		return context;
	}

	private SpringApplicationRunListeners getRunListeners(String[] args) {
		Class<?>[] types = new Class<?>[] { SpringApplication.class, String[].class };
		return new SpringApplicationRunListeners(logger,
				getSpringFactoriesInstances(SpringApplicationRunListener.class, types, this, args));
	}

	private <T> Collection<T> getSpringFactoriesInstances(Class<T> type, Class<?>[] parameterTypes, Object... args) {
		ClassLoader classLoader = getClassLoader();
		// Use names and ensure unique to protect against duplicates
		Set<String> names = new LinkedHashSet<>(SpringFactoriesLoader.loadFactoryNames(type, classLoader));
		List<T> instances = createSpringFactoriesInstances(type, parameterTypes, classLoader, args, names);
		AnnotationAwareOrderComparator.sort(instances);
		return instances;
	}

//準(zhǔn)備啟動(dòng)參數(shù)就不說(shuō)了
			ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);


	private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
			ApplicationArguments applicationArguments) {
		// Create and configure the environment
		//創(chuàng)建一個(gè)environment對(duì)象
		ConfigurableEnvironment environment = getOrCreateEnvironment();
		//配置環(huán)境 PropertySources Profiles
		configureEnvironment(environment, applicationArguments.getSourceArgs());
		//PropertySources
		ConfigurationPropertySources.attach(environment);
		//環(huán)境準(zhǔn)備
		listeners.environmentPrepared(environment);
		//將環(huán)境綁定到oSpringApplication(
		bindToSpringApplication(environment);
		if (!this.isCustomEnvironment) {
			environment = new EnvironmentConverter(getClassLoader()).convertEnvironmentIfNecessary(environment,
					deduceEnvironmentClass());
		}
		//配置PropertySources-如果有attach到environment
		ConfigurationPropertySources.attach(environment);
		return environment;
	}

	protected ConfigurableApplicationContext createApplicationContext() {
		//獲取上下文的類
		Class<?> contextClass = this.applicationContextClass;
		if (contextClass == null) {
			try {
				switch (this.webApplicationType) {
					//判斷Web應(yīng)用類型
				case SERVLET:
					contextClass = Class.forName(DEFAULT_SERVLET_WEB_CONTEXT_CLASS);
					break;
				case REACTIVE:
					contextClass = Class.forName(DEFAULT_REACTIVE_WEB_CONTEXT_CLASS);
					break;
				default:
					contextClass = Class.forName(DEFAULT_CONTEXT_CLASS);
				}
			}
			catch (ClassNotFoundException ex) {
				throw new IllegalStateException(
						"Unable create a default ApplicationContext, please specify an ApplicationContextClass", ex);
			}
		}
		return (ConfigurableApplicationContext) BeanUtils.instantiateClass(contextClass);
	}

private void prepareContext(ConfigurableApplicationContext context, ConfigurableEnvironment environment,
			SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments, Banner printedBanner) {
			//設(shè)置環(huán)境
		context.setEnvironment(environment);
		//處理上下文
		postProcessApplicationContext(context);
		//獲取所有ApplicationContextInitializer,執(zhí)行ApplicationContextInitializer的init方法
		applyInitializers(context);
		//調(diào)用SpringApplicationRunListener的contextPrepared,表示容器已經(jīng)準(zhǔn)備
		listeners.contextPrepared(context);
		//日志
		if (this.logStartupInfo) {
			logStartupInfo(context.getParent() == null);
			logStartupProfileInfo(context);
		}
		// Add boot specific singleton beans
		//獲取beanfactory,注冊(cè)相關(guān)bean
		ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
		beanFactory.registerSingleton("springApplicationArguments", applicationArguments);
		if (printedBanner != null) {
			beanFactory.registerSingleton("springBootBanner", printedBanner);
		}
		if (beanFactory instanceof DefaultListableBeanFactory) {
			((DefaultListableBeanFactory) beanFactory)
					.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
		}
		//延遲加載
		if (this.lazyInitialization) {
			context.addBeanFactoryPostProcessor(new LazyInitializationBeanFactoryPostProcessor());
		}
		// Load the sources
		Set<Object> sources = getAllSources();
		Assert.notEmpty(sources, "Sources must not be empty");
		//加載啟動(dòng)類
		load(context, sources.toArray(new Object[0]));
		//調(diào)用SpringApplicationRunListener的contextPrepared,表示容器已經(jīng)loaded事件
		listeners.contextLoaded(context);
	}