1.美图
2.概述
使用方式参考：Spring ： ImportBeanDefinitionRegistrar动态注入
DynamicImportBeanDefinitionRegistrar是被导入的,所以要加载到DynamicImportBeanDefinitionRegistrar必然要先加载DynamicConfiguration才行；所以先看Configuration的代码。
找到ConfigurationClassPostProcessor类，它实现了BeanDefinitionRegistryPostProcessor接口，在AbstractApplicationContext#invokeBeanFactoryPostProcessors方法有这样一段代码。
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());
。。。。
}
然后进去
public static void invokeBeanFactoryPostProcessors(
ConfigurableListableBeanFactory beanFactory, List<BeanFactoryPostProcessor> beanFactoryPostProcessors) {
// Invoke BeanDefinitionRegistryPostProcessors first, if any.
Set<String> processedBeans = new HashSet<>();
// 对 BeanDefinitionRegistry 类型处理
if (beanFactory instanceof BeanDefinitionRegistry) {
// 强转
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
// 普通的处理器
List<BeanFactoryPostProcessor> regularPostProcessors = new ArrayList<>();
//注册处理器
List<BeanDefinitionRegistryPostProcessor> registryProcessors = new ArrayList<>();
// 这里就是硬编码处理 因为这里是从 getBeanFactoryPostProcessors()方法获取的 可以硬编码从addBeanFactoryPostProcessor（）方法添加
for (BeanFactoryPostProcessor postProcessor : beanFactoryPostProcessors) {
if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {
// 对于 BeanDefinitionRegistryPostProcessor 类型 在 BeanFactoryPostProcessor 的基础上还有自己的定义，需要先调用
BeanDefinitionRegistryPostProcessor registryProcessor =
(BeanDefinitionRegistryPostProcessor) postProcessor;
// 执行 继承 BeanDefinitionRegistryPostProcessor 类的 postProcessBeanDefinitionRegistry 方法
registryProcessor.postProcessBeanDefinitionRegistry(registry);
registryProcessors.add(registryProcessor);
}
else {
regularPostProcessors.add(postProcessor);
}
}
//上边的For循环只是调用了硬编码的 BeanDefinitionRegistryPostProcessor 中的 postProcessBeanDefinitionRegistry 方法，
// 但是 BeanFactoryPostProcessor 中的 postProcessBeanFactory 方法还没有调用，是在方法的最后一行
// invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
// invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory); 这两个方法中执行的，
// 下面是自动处理器 获取类型是BeanDefinitionRegistryPostProcessor beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false); 获取的
// Do not initialize FactoryBeans here: We need to leave all regular beans
// uninitialized to let the bean factory post-processors apply to them!
// Separate between BeanDefinitionRegistryPostProcessors that implement
// PriorityOrdered, Ordered, and the rest.
// 当前注册处理器
List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();
// First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
// 首先调用实现了 PriorityOrdered 的 BeanDefinitionRegistryPostProcessors
String[] postProcessorNames =
beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
processedBeans.add(ppName);
}
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
// 执行 BeanDefinitionRegistryPostProcessor类的postProcessBeanDefinitionRegistry方法
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();
// Next, invoke the BeanDefinitionRegistryPostProcessors that implement Ordered.
// 下一个 ，调用实现 Ordered 的 BeanDefinitionRegistryPostProcessors
postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
if (!processedBeans.contains(ppName) && beanFactory.isTypeMatch(ppName, Ordered.class)) {
currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
processedBeans.add(ppName);
}
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
// 执行 BeanDefinitionRegistryPostProcessor类的postProcessBeanDefinitionRegistry方法
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();
// Finally, invoke all other BeanDefinitionRegistryPostProcessors until no further ones appear.
// 最后，调用所有其他BeanDefinitionRegistryPostProcessors，直到不再显示其他BeanDefinitionRegistryPostProcessors 无序的
boolean reiterate = true;
while (reiterate) {
reiterate = false;
postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
if (!processedBeans.contains(ppName)) {
currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
processedBeans.add(ppName);
reiterate = true;
}
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
// 执行 BeanDefinitionRegistryPostProcessor类的postProcessBeanDefinitionRegistry方法
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();
}
// Now, invoke the postProcessBeanFactory callback of all processors handled so far.
// 现在，调用到目前为止处理的所有处理器的 执行BeanFactoryPostProcessor 类的 postProcessBeanFactory 方法
// 这里执行的是 硬编码 和 非硬编码（自动）的 BeanFactoryPostProcessor 类的 postProcessBeanFactory 方法 分为硬编码处理器 和 普通处理器
invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
}
else {
// Invoke factory processors registered with the context instance.
// 调用在上下文实例中注册的工厂处理器的postProcessBeanFactory方法。 就是硬编码 通过 addBeanFactoryPostProcessor
// 方法添加的BeanFactoryPostProcessor
invokeBeanFactoryPostProcessors(beanFactoryPostProcessors, beanFactory);
}
// Do not initialize FactoryBeans here: We need to leave all regular beans
// uninitialized to let the bean factory post-processors apply to them!
String[] postProcessorNames =
beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);
// 自动处理 非硬编码 获取类型为是BeanFactoryPostProcessor beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);
// Separate between BeanFactoryPostProcessors that implement PriorityOrdered,
// Ordered, and the rest.
List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
List<String> orderedPostProcessorNames = new ArrayList<>();
List<String> nonOrderedPostProcessorNames = new ArrayList<>();
for (String ppName : postProcessorNames) {
if (processedBeans.contains(ppName)) {
// skip - already processed in first phase above
}
else if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
priorityOrderedPostProcessors.add(beanFactory.getBean(ppName, BeanFactoryPostProcessor.class));
}
else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
orderedPostProcessorNames.add(ppName);
}
else {
nonOrderedPostProcessorNames.add(ppName);
}
}
// First, invoke the BeanFactoryPostProcessors that implement PriorityOrdered.
sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);
// Next, invoke the BeanFactoryPostProcessors that implement Ordered.
List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<>();
for (String postProcessorName : orderedPostProcessorNames) {
orderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
}
sortPostProcessors(orderedPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);
// Finally, invoke all other BeanFactoryPostProcessors.
List<BeanFactoryPostProcessor> nonOrderedPostProcessors = new ArrayList<>();
for (String postProcessorName : nonOrderedPostProcessorNames) {
nonOrderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
}
invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);
// Clear cached merged bean definitions since the post-processors might have
// modified the original metadata, e.g. replacing placeholders in values...
beanFactory.clearMetadataCache();
}
private static void invokeBeanDefinitionRegistryPostProcessors(
Collection<? extends BeanDefinitionRegistryPostProcessor> postProcessors, BeanDefinitionRegistry registry) {
for (BeanDefinitionRegistryPostProcessor postProcessor : postProcessors) {
postProcessor.postProcessBeanDefinitionRegistry(registry);
}
}
这段代码的意图很明显，这里是从spring容器中拿到实现了BeanDefinitionRegistryPostProcessor接口的类。拿到后执行对应的postProcessBeanDefinitionRegistry方法(题外话:目前看到mybatis源码MapperScannerConfigurer也是实现这个接口，然后扫描mapper,注入进spring容器的)。
现在定位到ConfigurationClassPostProcessor#postProcessBeanDefinitionRegistry方法。
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
//取得registry的id并做判重处理或记录
int registryId = System.identityHashCode(registry);
if (this.registriesPostProcessed.contains(registryId)) {
throw new IllegalStateException(
"postProcessBeanDefinitionRegistry already called on this post-processor against " + registry);
}
if (this.factoriesPostProcessed.contains(registryId)) {
throw new IllegalStateException(
"postProcessBeanFactory already called on this post-processor against " + registry);
}
//保存处理过的registry，避免重复处理
this.registriesPostProcessed.add(registryId);
//处理java配置形式的bean定义
processConfigBeanDefinitions(registry);
}
processConfigBeanDefinitions方法
public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
List<BeanDefinitionHolder> configCandidates = new ArrayList<>();
//1、所有的BeanDefiniton的name，加载当前已知所有bean定义
String[] candidateNames = registry.getBeanDefinitionNames();
for (String beanName : candidateNames) {
BeanDefinition beanDef = registry.getBeanDefinition(beanName);
// 判断对应bean是否为配置类,如果是,则加入到configCandidates
if (ConfigurationClassUtils.isFullConfigurationClass(beanDef) ||
ConfigurationClassUtils.isLiteConfigurationClass(beanDef)) {
if (logger.isDebugEnabled()) {
logger.debug("Bean definition has already been processed as a configuration class: " + beanDef);
}
}
//2、将所有的@Configuration的类放入configCandidates中
else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.metadataReaderFactory)) {
configCandidates.add(new BeanDefinitionHolder(beanDef, beanName));
}
}
// Return immediately if no @Configuration classes were found
//如果找不到@configuration类，则立即返回
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
// 3. 如果BeanDefinitionRegistry 是SingletonBeanRegistry 子类的话,由于我们当前传入的是DefaultListableBeanFactory,是
// SingletonBeanRegistry 的子类。因此会将registry强转为SingletonBeanRegistry
SingletonBeanRegistry sbr = null;
if (registry instanceof SingletonBeanRegistry) {
sbr = (SingletonBeanRegistry) registry;
if (!this.localBeanNameGeneratorSet) {
// 如果localBeanNameGeneratorSet 等于false 并且SingletonBeanRegistry 中有 id 为 org.springframework.context.annotation.internalConfigurationBeanNameGenerator
// 的bean .则将componentScanBeanNameGenerator,importBeanNameGenerator 赋值为 该bean.
BeanNameGenerator generator = (BeanNameGenerator) sbr.getSingleton(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
// 实例化ConfigurationClassParser 为了解析 各个配置类
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 {
//3、解析所有的@Configuration类里面所有的注解（@Bean、@Profile、@Import、@ImportResource、@ComponentScan、@Lazy、@PropertySource）
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());
}
//4、通过解析成的configClasses，将所有的配置转化成BeanDefinition
this.reader.loadBeanDefinitions(configClasses);
alreadyParsed.addAll(configClasses);
candidates.clear();
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();
}
}
ConfigurationClassParser#parse方法
protected final void parse(@Nullable String className, String beanName) throws IOException {
Assert.notNull(className, "No bean class name for configuration class bean definition");
MetadataReader reader = this.metadataReaderFactory.getMetadataReader(className);
processConfigurationClass(new ConfigurationClass(reader, beanName));
}
protected void processConfigurationClass(ConfigurationClass configClass) throws IOException {
...................
// Recursively process the configuration class and its superclass hierarchy.
do {
//重点
metadata = doProcessConfigurationClass(configClass, metadata);
}
while (metadata != null);
.................
}
处理配置类的注解
@Nullable
protected final SourceClass doProcessConfigurationClass(ConfigurationClass configClass, SourceClass sourceClass)
throws IOException {
if (configClass.getMetadata().isAnnotated(Component.class.getName())) {
// Recursively process any member (nested) classes first
processMemberClasses(configClass, sourceClass);
}
// Process any @PropertySource annotations
//处理@PropertySource 加载外面资源文件
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
//处理 @ComponentScan 扫描包
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
//处理@Import注解
processImports(configClass, sourceClass, getImports(sourceClass), 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
//处理@Bean注解
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;
}
调用ImportBeanDefinitionRegistrar接口实现类的地方也找到了，下面看DefaultListableBeanFactory#registerBeanDefinition方法。
/**
* 向IOC容器注册解析的BeanDefiniton
* @param beanName the name of the bean instance to register
* @param beanDefinition definition of the bean instance to register
* @throws BeanDefinitionStoreException
*/
@Override
public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition)
throws BeanDefinitionStoreException {
Assert.hasText(beanName, "Bean name must not be empty");
Assert.notNull(beanDefinition, "BeanDefinition must not be null");
//校验解析的BeanDefiniton，如果beanDefinition是AbstractBeanDefinition实例,则验证
if (beanDefinition instanceof AbstractBeanDefinition) {
try {
//验证不能将静态工厂方法与方法重写相结合(静态工厂方法必须创建实例) 此处的检验是针对AbstractBeanDefinition的属性methodOverrides的检验
((AbstractBeanDefinition) beanDefinition).validate();
}
catch (BeanDefinitionValidationException ex) {
throw new BeanDefinitionStoreException(beanDefinition.getResourceDescription(), beanName,
"Validation of bean definition failed", ex);
}
}
// 2、优先尝试从缓存中加载BeanDefinition
BeanDefinition existingDefinition = this.beanDefinitionMap.get(beanName);
if (existingDefinition != null) {
// beanName已经存在且不允许被覆盖，抛出异常
if (!isAllowBeanDefinitionOverriding()) {
throw new BeanDefinitionOverrideException(beanName, beanDefinition, existingDefinition);
}
// 使用新的BeanDefinition覆盖已经加载的BeanDefinition，if else中只有日志打印，无实质代码，删除为了阅读方便
else if (existingDefinition.getRole() < beanDefinition.getRole()) {
// e.g. was ROLE_APPLICATION, now overriding with ROLE_SUPPORT or ROLE_INFRASTRUCTURE
if (logger.isInfoEnabled()) {
logger.info("Overriding user-defined bean definition for bean '" + beanName +
"' with a framework-generated bean definition: replacing [" +
existingDefinition + "] with [" + beanDefinition + "]");
}
}
//覆盖 beanDefinition 与 被覆盖的 beanDefinition 不相同，打印 debug 日志
else if (!beanDefinition.equals(existingDefinition)) {
if (logger.isDebugEnabled()) {
logger.debug("Overriding bean definition for bean '" + beanName +
"' with a different definition: replacing [" + existingDefinition +
"] with [" + beanDefinition + "]");
}
}
//其他的,都打印debug日志
else {
if (logger.isTraceEnabled()) {
logger.trace("Overriding bean definition for bean '" + beanName +
"' with an equivalent definition: replacing [" + existingDefinition +
"] with [" + beanDefinition + "]");
}
}
//允许覆盖，直接覆盖原有的 BeanDefinition 到 beanDefinitionMap 中。
this.beanDefinitionMap.put(beanName, beanDefinition);
}
// 3、缓存中无对应的BeanDefinition，则直接注册
else {
// 如果beanDefinition已经被标记为创建(为了解决单例bean的循环依赖问题)
if (hasBeanCreationStarted()) {
// Cannot modify startup-time collection elements anymore (for stable iteration)
//注册的过程中需要线程同步，以保证数据的一致性
synchronized (this.beanDefinitionMap) {
// 将beanDefinition保存到beanDefinitionMap中
this.beanDefinitionMap.put(beanName, beanDefinition);
// 创建List<String>并将缓存的beanDefinitionNames和新解析的beanName加入集合，对beanDefinitionNames进行重新的扩容操作
List<String> updatedDefinitions = new ArrayList<>(this.beanDefinitionNames.size() + 1);
//添加扩容之前的
updatedDefinitions.addAll(this.beanDefinitionNames);
//添加beanName到updatedDefinitions中
updatedDefinitions.add(beanName);
// 将updatedDefinitions赋值给beanDefinitionNames
this.beanDefinitionNames = updatedDefinitions;
// 如果manualSingletonNames中包含新注册的beanName
removeManualSingletonName(beanName);
}
}
else {
// Still in startup registration phase
// 将beanDefinition信息维护至缓存
// beanDefinitionMap-->(key->beanName,value->beanDefinition)
this.beanDefinitionMap.put(beanName, beanDefinition);
// beanDefinitionNames-->维护了beanName集合
this.beanDefinitionNames.add(beanName);
// manualSingletonNames缓存了手动注册的单例bean，所以需要调用一下remove方法，防止beanName重复
// 例如：xmlBeanFactory.registerSingleton("myDog", new Dog());
// 就可以向manualSingletonNames中注册单例bean
removeManualSingletonName(beanName);
}
this.frozenBeanDefinitionNames = null;
}
//检查是否有同名的BeanDefinition已经在IOC容器中注册
// 4、重置BeanDefinition，
// 当前注册的bean的定义已经在beanDefinitionMap缓存中存在，
// 或者其实例已经存在于单例bean的缓存中
if (existingDefinition != null || containsSingleton(beanName)) {
//重置所有已经注册过的BeanDefinition的缓存
resetBeanDefinition(beanName);
}
}
这段代码主要就是把定义的bean放到beanDefinitionMap里去。beanDefinitionMap维护的就是bean的定义，当需要获取的时候就从里面拿到对应的BeanDefinition，根据BeanDefinition生成一个对象。
至此ImportBeanDefinitionRegistrar接口的初始化及调用过程完毕。
