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

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

public SpringApplication(Class<?>... primarySources) {
		this(null, primarySources);
	}

public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
                            //资源加载器
		this.resourceLoader = resourceLoader;
		Assert.notNull(primarySources, "PrimarySources must not be null");
                            //加载源，这里就是MySpringBootApplication.class
		this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
                            //判断APP应用的类型，类型有；NONE-无需WEB的jar应用，SERVLET、REACTIVE-两个类型的Web应用
		this.webApplicationType = WebApplicationType.deduceFromClasspath();
                            //创建初始化器
		this.bootstrapRegistryInitializers = new ArrayList<>(
				getSpringFactoriesInstances(BootstrapRegistryInitializer.class));
		setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
                            //设置监听器
		setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
                            //应用主类
		this.mainApplicationClass = deduceMainApplicationClass();
	}

static WebApplicationType deduceFromClasspath() {
                            //REACTIVE栈
        if (ClassUtils.isPresent(WEBFLUX_INDICATOR_CLASS, null) && !ClassUtils.isPresent(WEBMVC_INDICATOR_CLASS, null)
        && !ClassUtils.isPresent(JERSEY_INDICATOR_CLASS, null)) {
        return WebApplicationType.REACTIVE;
        }
                            //尝试加载 SERVLET_INDICATOR_CLASSES = { "jakarta.servlet.Servlet","org.springframework.web.context.ConfigurableWebApplicationContext" };
        for (String className : SERVLET_INDICATOR_CLASSES) {
        if (!ClassUtils.isPresent(className, null)) {
        return WebApplicationType.NONE;
              }
            }
                            //加载Servlet和ConfigurableWebApplicationContext都成功,返回SERVLET
        return WebApplicationType.SERVLET;
        }

protected void initStrategies(ApplicationContext context) {
		initMultipartResolver(context);
		initLocaleResolver(context);
		initThemeResolver(context);
		initHandlerMappings(context);
		initHandlerAdapters(context);
		initHandlerExceptionResolvers(context);
		initRequestToViewNameTranslator(context);
		initViewResolvers(context);
		initFlashMapManager(context);
	}

                        //FACTORIES_RESOURCE_LOCATION="META-INF/spring.factories"
public static SpringFactoriesLoader forDefaultResourceLocation(@Nullable ClassLoader classLoader) {
		return forResourceLocation(FACTORIES_RESOURCE_LOCATION, classLoader);
	}

public static SpringFactoriesLoader forResourceLocation(String resourceLocation, @Nullable ClassLoader classLoader) {
		Assert.hasText(resourceLocation, "'resourceLocation' must not be empty");
		ClassLoader resourceClassLoader = (classLoader != null ? classLoader :
				SpringFactoriesLoader.class.getClassLoader());
		Map<String, SpringFactoriesLoader> loaders = cache.computeIfAbsent(
				resourceClassLoader, key -> new ConcurrentReferenceHashMap<>());
		return loaders.computeIfAbsent(resourceLocation, key ->
				new SpringFactoriesLoader(classLoader, loadFactoriesResource(resourceClassLoader, resourceLocation)));
	}

	protected static Map<String, List<String>> loadFactoriesResource(ClassLoader classLoader, String resourceLocation) {
		Map<String, List<String>> result = new LinkedHashMap<>();
		try {
			Enumeration<URL> urls = classLoader.getResources(resourceLocation);
			while (urls.hasMoreElements()) {
				UrlResource resource = new UrlResource(urls.nextElement());
				Properties properties = PropertiesLoaderUtils.loadProperties(resource);
				properties.forEach((name, value) -> {
					String[] factoryImplementationNames = StringUtils.commaDelimitedListToStringArray((String) value);
					List<String> implementations = result.computeIfAbsent(((String) name).trim(),
							key -> new ArrayList<>(factoryImplementationNames.length));
					Arrays.stream(factoryImplementationNames).map(String::trim).forEach(implementations::add);
				});
			}
			result.replaceAll(SpringFactoriesLoader::toDistinctUnmodifiableList);
		}
		catch (IOException ex) {
			throw new IllegalArgumentException("Unable to load factories from location [" + resourceLocation + "]", ex);
		}
		return Collections.unmodifiableMap(result);
	}

                    //创建一个类型的,配置中的所有对应的实现类的实例
public <T> List<T> load(Class<T> factoryType, @Nullable ArgumentResolver argumentResolver,
			@Nullable FailureHandler failureHandler) {

		Assert.notNull(factoryType, "'factoryType' must not be null");
		List<String> implementationNames = loadFactoryNames(factoryType);
		logger.trace(LogMessage.format("Loaded [%s] names: %s", factoryType.getName(), implementationNames));
		List<T> result = new ArrayList<>(implementationNames.size());
		FailureHandler failureHandlerToUse = (failureHandler != null) ? failureHandler : THROWING_FAILURE_HANDLER;
		for (String implementationName : implementationNames) {
			T factory = instantiateFactory(implementationName, factoryType, argumentResolver, failureHandlerToUse);
			if (factory != null) {
				result.add(factory);
			}
		}
		AnnotationAwareOrderComparator.sort(result);
		return result;
	}

/**
 * 一个正常的接口
 */
public interface TestSpiInterface {
    /**
     * 测试方法
     */
    void test();
}

/**
 * 实现类，可以是多个，可以不是本工程或者包，允许从第三方jar包中获取
 */
public class TestSpiInterfaceA implements TestSpiInterface {
    @Override
    public void test() {
        System.out.println("TestSpiInterfaceA");
    }
}


/**
 * 实现类，可以是多个，可以不是本工程或者包，允许从第三方jar包中获取
 */
public class TestSpiInterfaceB implements TestSpiInterface {
    @Override
    public void test() {
        System.out.println("TestSpiInterfaceB");
    }
}
/**
 * 实现类，可以是多个，可以不是本工程或者包，允许从第三方jar包中获取
 */
public class TestSpiInterfaceC implements TestSpiInterface {
    @Override
    public void test() {
        System.out.println("TestSpiInterfaceC");
    }
}

 public static void main(String[] args) {
        // 通过ServiceLoader加载实现类
        ServiceLoader<TestSpiInterface> serviceLoader = ServiceLoader.load(TestSpiInterface.class);
        for (TestSpiInterface testSpiInterface : serviceLoader) {
            testSpiInterface.test();
        }
    }

private DefaultBootstrapContext createBootstrapContext() {
		DefaultBootstrapContext bootstrapContext = new DefaultBootstrapContext();
		this.bootstrapRegistryInitializers.forEach((initializer) -> initializer.initialize(bootstrapContext));
		return bootstrapContext;
	}

private SpringApplicationRunListeners getRunListeners(String[] args) {
		ArgumentResolver argumentResolver = ArgumentResolver.of(SpringApplication.class, this);
		argumentResolver = argumentResolver.and(String[].class, args);
		List<SpringApplicationRunListener> listeners = getSpringFactoriesInstances(SpringApplicationRunListener.class,
				argumentResolver);
		SpringApplicationHook hook = applicationHook.get();
		SpringApplicationRunListener hookListener = (hook != null) ? hook.getRunListener(this) : null;
		if (hookListener != null) {
			listeners = new ArrayList<>(listeners);
			listeners.add(hookListener);
		}
		return new SpringApplicationRunListeners(logger, listeners, this.applicationStartup);
	}

void starting(ConfigurableBootstrapContext bootstrapContext, Class<?> mainApplicationClass) {
		doWithListeners("spring.boot.application.starting", (listener) -> listener.starting(bootstrapContext),
				(step) -> {
					if (mainApplicationClass != null) {
						step.tag("mainApplicationClass", mainApplicationClass.getName());
					}
				});
	}

private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
			DefaultBootstrapContext bootstrapContext, ApplicationArguments applicationArguments) {
		// Create and configure the environment
                            //创建环境
		ConfigurableEnvironment environment = getOrCreateEnvironment();
                            //配置环境
		configureEnvironment(environment, applicationArguments.getSourceArgs());
		ConfigurationPropertySources.attach(environment);
                            //发布监听事件：环境已准备好
		listeners.environmentPrepared(bootstrapContext, environment);
		DefaultPropertiesPropertySource.moveToEnd(environment);
		Assert.state(!environment.containsProperty("spring.main.environment-prefix"),
				"Environment prefix cannot be set via properties.");
		bindToSpringApplication(environment);
		if (!this.isCustomEnvironment) {
			EnvironmentConverter environmentConverter = new EnvironmentConverter(getClassLoader());
			environment = environmentConverter.convertEnvironmentIfNecessary(environment, deduceEnvironmentClass());
		}
		ConfigurationPropertySources.attach(environment);
		return environment;
	}

	@Override
	public void environmentPrepared(ConfigurableBootstrapContext bootstrapContext,
			ConfigurableEnvironment environment) {
		multicastInitialEvent(
				new ApplicationEnvironmentPreparedEvent(bootstrapContext, this.application, this.args, environment));
	}

@Override
	public void onApplicationEvent(ApplicationEvent event) {
		if (event instanceof ApplicationEnvironmentPreparedEvent environmentPreparedEvent) {
			onApplicationEnvironmentPreparedEvent(environmentPreparedEvent);
		}
		if (event instanceof ApplicationPreparedEvent) {
			onApplicationPreparedEvent();
		}
		if (event instanceof ApplicationFailedEvent) {
			onApplicationFailedEvent();
		}
	}

private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {
		ConfigurableEnvironment environment = event.getEnvironment();
		SpringApplication application = event.getSpringApplication();
		for (EnvironmentPostProcessor postProcessor : getEnvironmentPostProcessors(application.getResourceLoader(),
				event.getBootstrapContext())) {
			postProcessor.postProcessEnvironment(environment, application);
		}
	}

@Override
	public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
		postProcessEnvironment(environment, application.getResourceLoader(), application.getAdditionalProfiles());
	}

static {
		List<ConfigDataLocation> locations = new ArrayList<>();
		locations.add(ConfigDataLocation.of("optional:classpath:/;optional:classpath:/config/"));
		locations.add(ConfigDataLocation.of("optional:file:./;optional:file:./config/;optional:file:./config/*/"));
		DEFAULT_SEARCH_LOCATIONS = locations.toArray(new ConfigDataLocation[0]);
	}

private void prepareContext(DefaultBootstrapContext bootstrapContext, ConfigurableApplicationContext context,
			ConfigurableEnvironment environment, SpringApplicationRunListeners listeners,
			ApplicationArguments applicationArguments, Banner printedBanner) {
                        //设置环境
		context.setEnvironment(environment);
                        //一些后置处理
		postProcessApplicationContext(context);
                        //aot相关
		addAotGeneratedInitializerIfNecessary(this.initializers);
                        //初始化器的初始化方法
		applyInitializers(context);
		listeners.contextPrepared(context);
		bootstrapContext.close(context);
		if (this.logStartupInfo) {
			logStartupInfo(context.getParent() == null);
			logStartupProfileInfo(context);
		}
		// Add boot specific singleton beans
                        //注册相关Bean
		ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
		beanFactory.registerSingleton("springApplicationArguments", applicationArguments);
		if (printedBanner != null) {
			beanFactory.registerSingleton("springBootBanner", printedBanner);
		}
		if (beanFactory instanceof AbstractAutowireCapableBeanFactory autowireCapableBeanFactory) {
			autowireCapableBeanFactory.setAllowCircularReferences(this.allowCircularReferences);
			if (beanFactory instanceof DefaultListableBeanFactory listableBeanFactory) {
				listableBeanFactory.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
			}
		}
		if (this.lazyInitialization) {
			context.addBeanFactoryPostProcessor(new LazyInitializationBeanFactoryPostProcessor());
		}
		context.addBeanFactoryPostProcessor(new PropertySourceOrderingBeanFactoryPostProcessor(context));
		if (!AotDetector.useGeneratedArtifacts()) {
			// Load the sources
			Set<Object> sources = getAllSources();
			Assert.notEmpty(sources, "Sources must not be empty");
                        //注意看这行代码，注册启动类，也就是MySpringBootApplication这个类，和AnnotationConfigApplicationContext注册启动主配置类一样。
			load(context, sources.toArray(new Object[0]));
		}
		listeners.contextLoaded(context);
	}

private void load(Object source) {
		Assert.notNull(source, "Source must not be null");
		if (source instanceof Class<?> clazz) {
			load(clazz);
			return;
		}
		if (source instanceof Resource resource) {
			load(resource);
			return;
		}
		if (source instanceof Package pack) {
			load(pack);
			return;
		}
		if (source instanceof CharSequence sequence) {
			load(sequence);
			return;
		}
		throw new IllegalArgumentException("Invalid source type " + source.getClass());
	}

	private void refreshContext(ConfigurableApplicationContext context) {
		if (this.registerShutdownHook) {
			shutdownHook.registerApplicationContext(context);
		}
		refresh(context);
	}

@Override
	public void refresh() throws BeansException, IllegalStateException {
		synchronized (this.startupShutdownMonitor) {
			StartupStep contextRefresh = this.applicationStartup.start("spring.context.refresh");

			// Prepare this context for refreshing.
			prepareRefresh();

			// Tell the subclass to refresh the internal bean factory.
			ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

			// Prepare the bean factory for use in this context.
			prepareBeanFactory(beanFactory);

			try {
				// Allows post-processing of the bean factory in context subclasses.
				postProcessBeanFactory(beanFactory);

				StartupStep beanPostProcess = this.applicationStartup.start("spring.context.beans.post-process");
				// Invoke factory processors registered as beans in the context.
				invokeBeanFactoryPostProcessors(beanFactory);

				// Register bean processors that intercept bean creation.
				registerBeanPostProcessors(beanFactory);
				beanPostProcess.end();

				// Initialize message source for this context.
				initMessageSource();

				// Initialize event multicaster for this context.
				initApplicationEventMulticaster();

				// Initialize other special beans in specific context subclasses.
				onRefresh();

				// Check for listener beans and register them.
				registerListeners();

				// Instantiate all remaining (non-lazy-init) singletons.
				finishBeanFactoryInitialization(beanFactory);

				// Last step: publish corresponding event.
				finishRefresh();
			}

			catch (BeansException ex) {
				if (logger.isWarnEnabled()) {
					logger.warn("Exception encountered during context initialization - " +
							"cancelling refresh attempt: " + ex);
				}

				// Destroy already created singletons to avoid dangling resources.
				destroyBeans();

				// Reset 'active' flag.
				cancelRefresh(ex);

				// Propagate exception to caller.
				throw ex;
			}

			finally {
				// Reset common introspection caches in Spring's core, since we
				// might not ever need metadata for singleton beans anymore...
				resetCommonCaches();
				contextRefresh.end();
			}
		}
	}

/**
	 * Template method which can be overridden to add context-specific refresh work.
	 * Called on initialization of special beans, before instantiation of singletons.
	 * <p>This implementation is empty.
	 * @throws BeansException in case of errors
	 * @see #refresh()
	 */
	protected void onRefresh() throws BeansException {
		// For subclasses: do nothing by default.
	}

@Override
	protected void onRefresh() {
		super.onRefresh();
		try {
			createWebServer();
		}
		catch (Throwable ex) {
			throw new ApplicationContextException("Unable to start web server", ex);
		}
	}

	private void createWebServer() {
		WebServer webServer = this.webServer;
		ServletContext servletContext = getServletContext();
		if (webServer == null && servletContext == null) {
			StartupStep createWebServer = getApplicationStartup().start("spring.boot.webserver.create");
			ServletWebServerFactory factory = getWebServerFactory();
			createWebServer.tag("factory", factory.getClass().toString());
                            //创建WebServer
			this.webServer = factory.getWebServer(getSelfInitializer());
			createWebServer.end();
			getBeanFactory().registerSingleton("webServerGracefulShutdown",
					new WebServerGracefulShutdownLifecycle(this.webServer));
			getBeanFactory().registerSingleton("webServerStartStop",
					new WebServerStartStopLifecycle(this, this.webServer));
		}
		else if (servletContext != null) {
			try {
				getSelfInitializer().onStartup(servletContext);
			}
			catch (ServletException ex) {
				throw new ApplicationContextException("Cannot initialize servlet context", ex);
			}
		}
		initPropertySources();
	}

	/**
	 * Build and validate a configuration model based on the registry of
	 * {@link Configuration} classes.
	 */
	public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
		List<BeanDefinitionHolder> configCandidates = new ArrayList<>();
		String[] candidateNames = registry.getBeanDefinitionNames();

		for (String beanName : candidateNames) {
			BeanDefinition beanDef = registry.getBeanDefinition(beanName);
			if (beanDef.getAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE) != null) {
				if (logger.isDebugEnabled()) {
					logger.debug("Bean definition has already been processed as a configuration class: " + beanDef);
				}
			}
			else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.metadataReaderFactory)) {
				configCandidates.add(new BeanDefinitionHolder(beanDef, beanName));
			}
		}

		// Return immediately if no @Configuration classes were found
		if (configCandidates.isEmpty()) {
			return;
		}

		// Sort by previously determined @Order value, if applicable
		configCandidates.sort((bd1, bd2) -> {
			int i1 = ConfigurationClassUtils.getOrder(bd1.getBeanDefinition());
			int i2 = ConfigurationClassUtils.getOrder(bd2.getBeanDefinition());
			return Integer.compare(i1, i2);
		});

		// Detect any custom bean name generation strategy supplied through the enclosing application context
		SingletonBeanRegistry sbr = null;
		if (registry instanceof SingletonBeanRegistry _sbr) {
			sbr = _sbr;
			if (!this.localBeanNameGeneratorSet) {
				BeanNameGenerator generator = (BeanNameGenerator) sbr.getSingleton(
						AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR);
				if (generator != null) {
					this.componentScanBeanNameGenerator = generator;
					this.importBeanNameGenerator = generator;
				}
			}
		}

		if (this.environment == null) {
			this.environment = new StandardEnvironment();
		}

		// Parse each @Configuration class
		ConfigurationClassParser parser = new ConfigurationClassParser(
				this.metadataReaderFactory, this.problemReporter, this.environment,
				this.resourceLoader, this.componentScanBeanNameGenerator, registry);
                                //配置类候选集，在上面checkConfigurationClassCandidate通过@Configuration注解去判断，@SpringBootApplication内含了@Configuration注解
		Set<BeanDefinitionHolder> candidates = new LinkedHashSet<>(configCandidates);
		Set<ConfigurationClass> alreadyParsed = new HashSet<>(configCandidates.size());
		do {
			StartupStep processConfig = this.applicationStartup.start("spring.context.config-classes.parse");
                                //注意这行代码。从一个配置类解析相关的所有Bean信息。
			parser.parse(candidates);
			parser.validate();

			Set<ConfigurationClass> configClasses = new LinkedHashSet<>(parser.getConfigurationClasses());
			configClasses.removeAll(alreadyParsed);

			// Read the model and create bean definitions based on its content
			if (this.reader == null) {
				this.reader = new ConfigurationClassBeanDefinitionReader(
						registry, this.sourceExtractor, this.resourceLoader, this.environment,
						this.importBeanNameGenerator, parser.getImportRegistry());
			}
			this.reader.loadBeanDefinitions(configClasses);
			alreadyParsed.addAll(configClasses);
			processConfig.tag("classCount", () -> String.valueOf(configClasses.size())).end();

			candidates.clear();
			if (registry.getBeanDefinitionCount() > candidateNames.length) {
				String[] newCandidateNames = registry.getBeanDefinitionNames();
				Set<String> oldCandidateNames = Set.of(candidateNames);
				Set<String> alreadyParsedClasses = new HashSet<>();
				for (ConfigurationClass configurationClass : alreadyParsed) {
					alreadyParsedClasses.add(configurationClass.getMetadata().getClassName());
				}
				for (String candidateName : newCandidateNames) {
					if (!oldCandidateNames.contains(candidateName)) {
						BeanDefinition bd = registry.getBeanDefinition(candidateName);
						if (ConfigurationClassUtils.checkConfigurationClassCandidate(bd, this.metadataReaderFactory) &&
								!alreadyParsedClasses.contains(bd.getBeanClassName())) {
							candidates.add(new BeanDefinitionHolder(bd, candidateName));
						}
					}
				}
				candidateNames = newCandidateNames;
			}
		}
		while (!candidates.isEmpty());

		// Register the ImportRegistry as a bean in order to support ImportAware @Configuration classes
		if (sbr != null && !sbr.containsSingleton(IMPORT_REGISTRY_BEAN_NAME)) {
			sbr.registerSingleton(IMPORT_REGISTRY_BEAN_NAME, parser.getImportRegistry());
		}

		// Store the PropertySourceDescriptors to contribute them Ahead-of-time if necessary
		this.propertySourceDescriptors = parser.getPropertySourceDescriptors();

		if (this.metadataReaderFactory instanceof CachingMetadataReaderFactory cachingMetadataReaderFactory) {
			// Clear cache in externally provided MetadataReaderFactory; this is a no-op
			// for a shared cache since it'll be cleared by the ApplicationContext.
			cachingMetadataReaderFactory.clearCache();
		}
	}

	/**
	 * Apply processing and build a complete {@link ConfigurationClass} by reading the
	 * annotations, members and methods from the source class. This method can be called
	 * multiple times as relevant sources are discovered.
	 * @param configClass the configuration class being build
	 * @param sourceClass a source class
	 * @return the superclass, or {@code null} if none found or previously processed
	 */
	@Nullable
	protected final SourceClass doProcessConfigurationClass(
			ConfigurationClass configClass, SourceClass sourceClass, Predicate<String> filter)
			throws IOException {

		if (configClass.getMetadata().isAnnotated(Component.class.getName())) {
			// Recursively process any member (nested) classes first
			processMemberClasses(configClass, sourceClass, filter);
		}

		// Process any @PropertySource annotations
		for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(
				sourceClass.getMetadata(), PropertySources.class,
				org.springframework.context.annotation.PropertySource.class)) {
			if (this.propertySourceRegistry != null) {
				this.propertySourceRegistry.processPropertySource(propertySource);
			}
			else {
				logger.info("Ignoring @PropertySource annotation on [" + sourceClass.getMetadata().getClassName() +
						"]. Reason: Environment must implement ConfigurableEnvironment");
			}
		}

		// Process any @ComponentScan annotations
		Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(
				sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);
		if (!componentScans.isEmpty() &&
				!this.conditionEvaluator.shouldSkip(sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {
			for (AnnotationAttributes componentScan : componentScans) {
				// The config class is annotated with @ComponentScan -> perform the scan immediately
				Set<BeanDefinitionHolder> scannedBeanDefinitions =
						this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());
				// Check the set of scanned definitions for any further config classes and parse recursively if needed
				for (BeanDefinitionHolder holder : scannedBeanDefinitions) {
					BeanDefinition bdCand = holder.getBeanDefinition().getOriginatingBeanDefinition();
					if (bdCand == null) {
						bdCand = holder.getBeanDefinition();
					}
					if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {
						parse(bdCand.getBeanClassName(), holder.getBeanName());
					}
				}
			}
		}

		// Process any @Import annotations
		processImports(configClass, sourceClass, getImports(sourceClass), filter, true);

		// Process any @ImportResource annotations
		AnnotationAttributes importResource =
				AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);
		if (importResource != null) {
			String[] resources = importResource.getStringArray("locations");
			Class<? extends BeanDefinitionReader> readerClass = importResource.getClass("reader");
			for (String resource : resources) {
				String resolvedResource = this.environment.resolveRequiredPlaceholders(resource);
				configClass.addImportedResource(resolvedResource, readerClass);
			}
		}

		// Process individual @Bean methods
		Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);
		for (MethodMetadata methodMetadata : beanMethods) {
			configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
		}

		// Process default methods on interfaces
		processInterfaces(configClass, sourceClass);

		// Process superclass, if any
		if (sourceClass.getMetadata().hasSuperClass()) {
			String superclass = sourceClass.getMetadata().getSuperClassName();
			if (superclass != null && !superclass.startsWith("java") &&
					!this.knownSuperclasses.containsKey(superclass)) {
				this.knownSuperclasses.put(superclass, configClass);
				// Superclass found, return its annotation metadata and recurse
				return sourceClass.getSuperClass();
			}
		}

		// No superclass -> processing is complete
		return null;
	}

	/**
	 * Called after the context has been refreshed.
	 * @param context the application context
	 * @param args the application arguments
	 */
	protected void afterRefresh(ConfigurableApplicationContext context, ApplicationArguments args) {
	}

void started(ConfigurableApplicationContext context, Duration timeTaken) {
		doWithListeners("spring.boot.application.started", (listener) -> listener.started(context, timeTaken));
	}

private void callRunners(ApplicationContext context, ApplicationArguments args) {
		List<Object> runners = new ArrayList<>();
		runners.addAll(context.getBeansOfType(ApplicationRunner.class).values());
		runners.addAll(context.getBeansOfType(CommandLineRunner.class).values());
		AnnotationAwareOrderComparator.sort(runners);
		for (Object runner : new LinkedHashSet<>(runners)) {
			if (runner instanceof ApplicationRunner applicationRunner) {
				callRunner(applicationRunner, args);
			}
			if (runner instanceof CommandLineRunner commandLineRunner) {
				callRunner(commandLineRunner, args);
			}
		}
	}