springboot自动扫描添加的BeanDefinition源码实例详解

package com.example.bootargs;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class BootargsApplication {

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

}

	/**
	 * 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();
		//在下面的这个for循环中，会从beanFactory中已经有的bean的定义中寻找有Configuration注解的配置类。
    //默认这里获取到的只有一个包含SpringBootApplication注解的主类
		for (String beanName : candidateNames) {
				......
				configCandidates.add(new BeanDefinitionHolder(beanDef, beanName));
			}
		}
		
    //如果没有找到配置类，就直接返回
		// Return immediately if no @Configuration classes were found
		if (configCandidates.isEmpty()) {
			return;
		}

		......
		//在这里就通过ConfigurationClassParser去解析配置类
		// Parse each @Configuration class
		ConfigurationClassParser parser = new ConfigurationClassParser(
				this.metadataReaderFactory, this.problemReporter, this.environment,
				this.resourceLoader, this.componentScanBeanNameGenerator, registry);

		Set<BeanDefinitionHolder> candidates = new LinkedHashSet<>(configCandidates);
		Set<ConfigurationClass> alreadyParsed = new HashSet<>(configCandidates.size());
		do {
			StartupStep processConfig = this.applicationStartup.start("spring.context.config-classes.parse");
			//所有bean的定义的查找都是在这里完成的。下面我们去看看这里的parse方法
      parser.parse(candidates);
			......
	}

protected void processConfigurationClass(ConfigurationClass configClass, Predicate<String> filter) throws IOException {
  	//在这里首先看配置类上是否有Conditional注解，如果有的话，就去解析处理，看看是否要跳过这个注解类
		if (this.conditionEvaluator.shouldSkip(configClass.getMetadata(), ConfigurationPhase.PARSE_CONFIGURATION)) {
			return;
		}
		
  	//所有解析出来的配置类都要放置到configurationClasses中,key是当前解析出来的配置类,value就是表示这个配置类是通过谁来导入的。
  	//如果这个配置类不是通过别的类来导入的，这时key和value就是一样的。
		ConfigurationClass existingClass = this.configurationClasses.get(configClass);
  	//如果通过多个配置类导入了同一个配置类，那么把这个和配置类的导入关系就要进行一下合并
		if (existingClass != null) {
			if (configClass.isImported()) {
				if (existingClass.isImported()) {
					existingClass.mergeImportedBy(configClass);
				}
				// Otherwise ignore new imported config class; existing non-imported class overrides it.
				return;
			}
			else {
				// Explicit bean definition found, probably replacing an import.
				// Let's remove the old one and go with the new one.
				this.configurationClasses.remove(configClass);
				this.knownSuperclasses.values().removeIf(configClass::equals);
			}
		}

		// Recursively process the configuration class and its superclass hierarchy.
  	//这里是将配置类转化为SourceClass对象
		SourceClass sourceClass = asSourceClass(configClass, filter);
		do {
      //在这里就会进行真正的配置类的解析出来。
      
      //注意这里是个do-while循环，处理完当前的配置类，会继续去处理当前配置类的父类。
      //如果当前类的父类类名不是java开头,且没有被处理过的话，就会在这个do-while循环中继续去处理
      
			sourceClass = doProcessConfigurationClass(configClass, sourceClass, filter);
		}
		while (sourceClass != null);
		
		this.configurationClasses.put(configClass, configClass);
	}

@Configuration(proxyBeanMethods = false)
@ConditionalOnMissingBean(name = AbstractApplicationContext.MESSAGE_SOURCE_BEAN_NAME, search = SearchStrategy.CURRENT)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@Conditional(ResourceBundleCondition.class)
@EnableConfigurationProperties
public class MessageSourceAutoConfiguration 

	@Nullable
	protected final SourceClass doProcessConfigurationClass(
			ConfigurationClass configClass, SourceClass sourceClass, Predicate<String> filter)
			throws IOException {
		//在这里，查看类是否有Component注解，有的话，查找当前类的内部类，进行处理
		if (configClass.getMetadata().isAnnotated(Component.class.getName())) {
			// Recursively process any member (nested) classes first
      //这里就可能会递归调用到上面的processConfigurationClass方法
			processMemberClasses(configClass, sourceClass, filter);
		}

		// Process any @PropertySource annotations
    //在这里，查看类是否有PropertySources注解，有的话去解析属性配置，添加到环境上下文中去
		for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(
				sourceClass.getMetadata(), PropertySources.class,
				org.springframework.context.annotation.PropertySource.class)) {
			if (this.environment instanceof ConfigurableEnvironment) {
				processPropertySource(propertySource);
			}
			else {
				logger.info("Ignoring @PropertySource annotation on [" + sourceClass.getMetadata().getClassName() +
						"]. Reason: Environment must implement ConfigurableEnvironment");
			}
		}

		// Process any @ComponentScan annotations
    //在这里，查看类是否有ComponentScans注解，有的话，就根据这里的条件去进行目录扫描，查找bean的定义
    //由于我们当前的类上有SpringBootApplication注解，所以这里是能够找到ComponentScan注解的，就会进到这个方法里面去
		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
        //在这里，就会去处理ComponentScans注解相关的内容。
        //ComponentScans注解上有个basePackages属性，用来指定扫描的包的名字。
        //如果没有指定basePackages属性，就在当前类的包下及其所有子包下去查找相关的bean的定义。
        //我们一般不会指定basePackages属性，那么会在当前sourceClass类的包及其所有子包下去查找bean的定义。
        //我们自己代码中定义的controller,service,dao等等都是在这一步获取到bean的定义的。
				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)) {	
            //这里也会间接调用到processConfigurationClass方法
						parse(bdCand.getBeanClassName(), holder.getBeanName());
					}
				}
			}
		}

		// Process any @Import annotations
    //在这里，就会去处理类上的import注解。
    
    //getImports(sourceClass)首先会获取到import的类。
    //这里会有两个，一个是AutoConfigurationPackage上注解的AutoConfigurationPackages.Registrar.class
    //另一个是EnableAutoConfiguration上的注解AutoConfigurationImportSelector.class)
    
    //下面我们去看看processImports这个方法
   	//这里面也可能会调用到processConfigurationClass方法
		processImports(configClass, sourceClass, getImports(sourceClass), filter, true);
		......
	}

private void processImports(ConfigurationClass configClass, SourceClass currentSourceClass,
			Collection<SourceClass> importCandidates, Predicate<String> exclusionFilter,
			boolean checkForCircularImports) {
		
		if (importCandidates.isEmpty()) {
			return;
		}
		//这里是错误检查，检查是否出现了递归
		if (checkForCircularImports && isChainedImportOnStack(configClass)) {
			this.problemReporter.error(new CircularImportProblem(configClass, this.importStack));
		}
		else {
      //先将当前的配置类压入栈
			this.importStack.push(configClass);
			try {
        //这里，就会对import标签导入的类进行处理
				for (SourceClass candidate : importCandidates) {
          
          //AutoConfigurationImportSelector.class类就会走下面的分支
					if (candidate.isAssignable(ImportSelector.class)) {
						// Candidate class is an ImportSelector -> delegate to it to determine imports
						Class<?> candidateClass = candidate.loadClass();
            //首先在这里创建一个AutoConfigurationImportSelector类的对象，
						ImportSelector selector = ParserStrategyUtils.instantiateClass(candidateClass, ImportSelector.class,
								this.environment, this.resourceLoader, this.registry);
						Predicate<String> selectorFilter = selector.getExclusionFilter();
						if (selectorFilter != null) {
							exclusionFilter = exclusionFilter.or(selectorFilter);
						}
						if (selector instanceof DeferredImportSelector) {
            //在这里，将当前的配置类和AutoConfigurationImportSelector的对象封装成DeferredImportSelectorHolder对象
            //添加到延迟导入的集合deferredImportSelectors中
							this.deferredImportSelectorHandler.handle(configClass, (DeferredImportSelector) selector);
						}
						else {
							String[] importClassNames = selector.selectImports(currentSourceClass.getMetadata());
							Collection<SourceClass> importSourceClasses = asSourceClasses(importClassNames, exclusionFilter);
							processImports(configClass, currentSourceClass, importSourceClasses, exclusionFilter, false);
						}
					}
          //AutoConfigurationPackages.Registrar.class这个类就会走到这个分支中
          //在这个分支中，首先创建AutoConfigurationPackages.Registrar的对象
          //添加到当前配置类的importBeanDefinitionRegistrars属性中去
					else if (candidate.isAssignable(ImportBeanDefinitionRegistrar.class)) {
						// Candidate class is an ImportBeanDefinitionRegistrar ->
						// delegate to it to register additional bean definitions
						Class<?> candidateClass = candidate.loadClass();
						ImportBeanDefinitionRegistrar registrar =
								ParserStrategyUtils.instantiateClass(candidateClass, ImportBeanDefinitionRegistrar.class,
										this.environment, this.resourceLoader, this.registry);
						configClass.addImportBeanDefinitionRegistrar(registrar, currentSourceClass.getMetadata());
					}
					else {
						// Candidate class not an ImportSelector or ImportBeanDefinitionRegistrar ->
						// process it as an @Configuration class
						this.importStack.registerImport(
								currentSourceClass.getMetadata(), candidate.getMetadata().getClassName());
						processConfigurationClass(candidate.asConfigClass(configClass), exclusionFilter);
					}
				}
			}
			catch (BeanDefinitionStoreException ex) {
				throw ex;
			}
			catch (Throwable ex) {
				throw new BeanDefinitionStoreException(
						"Failed to process import candidates for configuration class [" +
						configClass.getMetadata().getClassName() + "]", ex);
			}
			finally {
				this.importStack.pop();
			}
		}
	}

	@Nullable
	protected final SourceClass doProcessConfigurationClass(
			ConfigurationClass configClass, SourceClass sourceClass, Predicate<String> filter)
			throws IOException {

			......//这部分前面已经分析过了，我们就继续看后面的吧

		// Process any @ImportResource annotations
    // 这里是处理ImportResource注解
		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
    //这里是处理配置类内部的有Bean注解的方法，添加到配置类的beanMethods属性中
		Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);
		for (MethodMetadata methodMetadata : beanMethods) {
			configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
		}

		// Process default methods on interfaces
    //这里处理配置类实现的接口上默认方法上有Bean注解的话,也添加到beanMethods属性中
		processInterfaces(configClass, sourceClass);

		// Process superclass, if any
    
    //这里去获取配置类的父类，如果存在父类且父类类名不是java开头且还没有被处理过，就会返回父类，继续进行父类的处理。
		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;
	}

public void parse(Set<BeanDefinitionHolder> configCandidates) {
		......
		//就会走到下面这行代码
		this.deferredImportSelectorHandler.process();
	}

		public void process() {
			
			//在上面代码中我们分析到this.deferredImportSelectors中只有一个
      //由前面的配置类和AutoConfigurationImportSelector类的对象封装的DeferredImportSelectorHolder对象
			List<DeferredImportSelectorHolder> deferredImports = this.deferredImportSelectors;
			this.deferredImportSelectors = null;
			try {
				if (deferredImports != null) {
					DeferredImportSelectorGroupingHandler handler = new DeferredImportSelectorGroupingHandler();
					deferredImports.sort(DEFERRED_IMPORT_COMPARATOR);
          //这里会对延迟导入的类进行分组，添加到handler中，由于我们这里只有一个对象，所以这块的分组，我们可以不用太关注
          //同时会将前面的配置类添加到handler对象的configurationClasses属性中
					deferredImports.forEach(handler::register);
          //下面就会交给handler去进行处理
					handler.processGroupImports();
				}
			}
			finally {
				this.deferredImportSelectors = new ArrayList<>();
			}
		}
	}

public void processGroupImports() {
  		//这里就按分组去处理了
			for (DeferredImportSelectorGrouping grouping : this.groupings.values()) {
				Predicate<String> exclusionFilter = grouping.getCandidateFilter();
        //这里的grouping.getImports()就回去获取系统的配置类,我们下面去看这个getImports
				grouping.getImports().forEach(entry -> {
				......
			}
		}

		public Iterable<Group.Entry> getImports() {
			//这里的deferredImports中只有一个对象，还是之前的DeferredImportSelectorHolder
			for (DeferredImportSelectorHolder deferredImport : this.deferredImports) {
        //这里的this.group就是之前分组的deferredImport.getImportSelector().getImportGroup();方法的返回值创建的对象
        //具体就是AutoConfigurationImportSelector.AutoConfigurationGroup的对象
        //下面我们先看看这个process方法
				this.group.process(deferredImport.getConfigurationClass().getMetadata(),
						deferredImport.getImportSelector());
			}
			return this.group.selectImports();
		}

		public void process(AnnotationMetadata annotationMetadata, DeferredImportSelector deferredImportSelector) {
			Assert.state(deferredImportSelector instanceof AutoConfigurationImportSelector,
					() -> String.format("Only %s implementations are supported, got %s",
							AutoConfigurationImportSelector.class.getSimpleName(),
							deferredImportSelector.getClass().getName()));
      //下面这行代码也比较重要，我们进去看看
			AutoConfigurationEntry autoConfigurationEntry = ((AutoConfigurationImportSelector) deferredImportSelector)
					.getAutoConfigurationEntry(annotationMetadata);
			this.autoConfigurationEntries.add(autoConfigurationEntry);
			for (String importClassName : autoConfigurationEntry.getConfigurations()) {
				this.entries.putIfAbsent(importClassName, annotationMetadata);
			}
		}

	protected AutoConfigurationEntry getAutoConfigurationEntry(AnnotationMetadata annotationMetadata) {
		//这里,我们就能看到设置spring.boot.enableautoconfiguration属性去禁止导入系统配置的bean的定义
		if (!isEnabled(annotationMetadata)) {
			return EMPTY_ENTRY;
		}

		AnnotationAttributes attributes = getAttributes(annotationMetadata);
    //在下面这行中，就能看到通过ClassLoader去加载META-INF/spring.factories文件，读取内容。放置到cache中
    //在当前这里,会去获取key=org.springframework.boot.autoconfigure.EnableAutoConfiguration的所有属性配置
		List<String> configurations = getCandidateConfigurations(annotationMetadata, attributes);
		configurations = removeDuplicates(configurations);
		Set<String> exclusions = getExclusions(annotationMetadata, attributes);
		checkExcludedClasses(configurations, exclusions);
		configurations.removeAll(exclusions);
    //在这里获取配置过滤类并创建对象，对上面的configuras进行过滤
    //这里的配置过滤类也是从cache中获取,key=org.springframework.boot.autoconfigure.AutoConfigurationImportFilter
		configurations = getConfigurationClassFilter().filter(configurations);
    //这行代码不关键，我们可以不用去关注
		fireAutoConfigurationImportEvents(configurations, exclusions);
    //这里返回一个AutoConfigurationEntry对象
    //其中configurations是过滤器能够匹配到的配置类,exclusions在我们这里是空的
		return new AutoConfigurationEntry(configurations, exclusions);
	}

		public void process(AnnotationMetadata annotationMetadata, DeferredImportSelector deferredImportSelector) {
			......//上面的代码刚才已经分析过了
      //在这里将上面返回的AutoConfigurationEntry对象添加到autoConfigurationEntries中
			this.autoConfigurationEntries.add(autoConfigurationEntry);
      
			for (String importClassName : autoConfigurationEntry.getConfigurations()) {
        //分别将添加的配置类添加到entries这个属性中
        //importClassName是新查找到的配置类,annotationMetadata都是同一个就是我们的主类
				this.entries.putIfAbsent(importClassName, annotationMetadata);
			}
		}

	public void processGroupImports() {
			for (DeferredImportSelectorGrouping grouping : this.groupings.values()) {
				Predicate<String> exclusionFilter = grouping.getCandidateFilter();
				//上面已经分析到grouping.getImports()返回的是Entry对象的集合
				grouping.getImports().forEach(entry -> {
          //entry.getMetadata()返回的还是我们之前的主类。
          //这里的configurationClass也是我们之前的主类。
          //这个主要是为了在processImports方法中创建的配置类为它们设置importedBy属性
					ConfigurationClass configurationClass = this.configurationClasses.get(entry.getMetadata());
					try {
            //这里又会调用到processImports这个方法。这个在前面已经分析过了，但是这里有一点不一样，下面我们看看不一样的地方
						processImports(configurationClass, asSourceClass(configurationClass, exclusionFilter),
								Collections.singleton(asSourceClass(entry.getImportClassName(), exclusionFilter)),
								exclusionFilter, false);
					}
					catch (BeanDefinitionStoreException ex) {
						throw ex;
					}
					catch (Throwable ex) {
						throw new BeanDefinitionStoreException(
								"Failed to process import candidates for configuration class [" +
										configurationClass.getMetadata().getClassName() + "]", ex);
					}
				});
			}
		}

	private void processImports(ConfigurationClass configClass, SourceClass currentSourceClass,
			Collection<SourceClass> importCandidates, Predicate<String> exclusionFilter,
			boolean checkForCircularImports) {

			this.importStack.push(configClass);
			try {
				for (SourceClass candidate : importCandidates) {
					if (candidate.isAssignable(ImportSelector.class)) {
					......
					}
					else if (candidate.isAssignable(ImportBeanDefinitionRegistrar.class)) {
					......	
					}
					else {

						// Candidate class not an ImportSelector or ImportBeanDefinitionRegistrar ->
						// process it as an @Configuration class
            //上次进入这个方法，分别走了上面的两个分支，现在大概率会走到这个分支
            //这里会将导入的类添加到imports属性中,key是新导入的配置类,value是我们之前的主类
						this.importStack.registerImport(
								currentSourceClass.getMetadata(), candidate.getMetadata().getClassName());
            //这里又会去处理新添加的配置类，在这里是有可能出现递归的，下面我们具体分析下这里的处理逻辑
						processConfigurationClass(candidate.asConfigClass(configClass), exclusionFilter);
					}
				}
			}
			......
		}
	}

	public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
    ......
		do {
			StartupStep processConfig = this.applicationStartup.start("spring.context.config-classes.parse");
			parser.parse(candidates);//前面已经分析到了这里
			parser.validate();

      //这里就会得到所有的配置类
			Set<ConfigurationClass> configClasses = new LinkedHashSet<>(parser.getConfigurationClasses());
      //alreadyParsed第一次是空的，由于这个方法是do-while循环，在后面会对这个变量赋值
			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());
			}
      //在这里就会对前面获取的所有的配置类添加到beanFactory中
			this.reader.loadBeanDefinitions(configClasses);
			alreadyParsed.addAll(configClasses);
			processConfig.tag("classCount", () -> String.valueOf(configClasses.size())).end();

			candidates.clear();
      //这里就是对比前后beanFactory中的beanDefinition数量是否有增加,如果有增加说明我们在本次do-while代码中添加了beanFactory
      //下面的逻辑主要是为了判断当前扫描出来的配置类是否全部添加进了beanFactory中,如果有配置类还没有被今天进去，就会循环，重新执行上面的逻辑
			if (registry.getBeanDefinitionCount() > candidateNames.length) {
				String[] newCandidateNames = registry.getBeanDefinitionNames();
				Set<String> oldCandidateNames = new HashSet<>(Arrays.asList(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());
		}

		if (this.metadataReaderFactory instanceof 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) this.metadataReaderFactory).clearCache();
		}
	}

	public void loadBeanDefinitions(Set<ConfigurationClass> configurationModel) {
		
		//这个类还是用来对Conditional注解进行处理，来判断当前配置类是否要被过滤掉
		TrackedConditionEvaluator trackedConditionEvaluator = new TrackedConditionEvaluator();
		for (ConfigurationClass configClass : configurationModel) {
			//在这里会对每个配置类及它的属性进行处理，封装成beanDefinition添加到beanFactory中去
			loadBeanDefinitionsForConfigurationClass(configClass, trackedConditionEvaluator);
		}
	}

	private void loadBeanDefinitionsForConfigurationClass(
			ConfigurationClass configClass, TrackedConditionEvaluator trackedConditionEvaluator) {
		
    //这里就会对Conditional注解进行判断，如果当前类是被导入的，就会去判断导入它的类
		if (trackedConditionEvaluator.shouldSkip(configClass)) {
			String beanName = configClass.getBeanName();
			if (StringUtils.hasLength(beanName) && this.registry.containsBeanDefinition(beanName)) {
				this.registry.removeBeanDefinition(beanName);
			}
			this.importRegistry.removeImportingClass(configClass.getMetadata().getClassName());
			return;
		}
		//如果类是被导入的，就会去对它进行处理
		if (configClass.isImported()) {
			registerBeanDefinitionForImportedConfigurationClass(configClass);
		}
    //下面就是对配置类的各种属性进行处理
    //处理方法上的bean注解
		for (BeanMethod beanMethod : configClass.getBeanMethods()) {
			loadBeanDefinitionsForBeanMethod(beanMethod);
		}
		//处理导入的资源
		loadBeanDefinitionsFromImportedResources(configClass.getImportedResources());
    //处理导入的ImportBeanDefinitionRegistrar
		loadBeanDefinitionsFromRegistrars(configClass.getImportBeanDefinitionRegistrars());
	}