Spring IOC

什么是spring

以前没有spring的时候，我们需要得到一个对象，都是自己主动去new一个对象，然后通过set方法给对象注入属性，但是这种动作其实是一个重复的动作，所以spring提供ioc的容器解决方案，在容器启动的时候就把许多需要实例化和属性注入的bean都提前做好并放入到一个map中存储起来。这就是控制反转，原来的控制全在用户，现在的控制权完全交给了容器，在bean实例化后，通过反射对属性进行依赖注入
有两种使用方式，一种是xml的方式，一种是注解的方式。
xml的加载方式，首先在spring的xml中通过bean标签配置我们需要注入的bean,当扫描到所有的bean后，首先把bean包装成BeanDeŨnition，放入到list中，然后循环这个list去创建bean,创建bean的步骤为实例化->属性注入->初始化->aop,然后最终放入到spring的一级缓存中保存起来。
注解方式是通过在类上面加上spring的注解去扫描，比如controller，service等，后续步骤和xml基本一样。

什么是ioc

IOC是一个容器，在spring创建对象的过程中使用到了很多的容器，这些我们都叫做IOC的容器
控制反转：原来是程序员掌握着对象的控制权，现在交给spring框架

定位资源

把扫描路径下的类的全名称放入到list中

把类变成beandefinition

 

为什么会有两份？因为将来可能通过类名称小写找对象或者接口全名称找对象 

 封装了一层，把原来的key当作map的key,原来的beandefinition当作map的值

实例化对象，并放入到缓存中

 开始属性注入

源码浅析

IoC初始化源码分析

package com.gupaoedu;import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;@Configuration
public class JavaConfig {public static void main(String[] args) {ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");ac.getBean(Person.class);}}

// ClassPathXmlApplicationContext.class
public ClassPathXmlApplicationContext(String[] configLocations, boolean refresh, @Nullable ApplicationContext parent) throws BeansException {super(parent);this.setConfigLocations(configLocations);if (refresh) {this.refresh();}}

// ClassPathXmlApplicationContext.class
public void refresh() throws BeansException, IllegalStateException {Object var1 = this.startupShutdownMonitor;synchronized(this.startupShutdownMonitor) {this.prepareRefresh();// IoC 容器的初始化操作ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();this.prepareBeanFactory(beanFactory);try {this.postProcessBeanFactory(beanFactory);this.invokeBeanFactoryPostProcessors(beanFactory);this.registerBeanPostProcessors(beanFactory);this.initMessageSource();this.initApplicationEventMulticaster();this.onRefresh();this.registerListeners();this.finishBeanFactoryInitialization(beanFactory);this.finishRefresh();} catch (BeansException var9) {if (this.logger.isWarnEnabled()) {this.logger.warn("Exception encountered during context initialization - cancelling refresh attempt: " + var9);}this.destroyBeans();this.cancelRefresh(var9);throw var9;} finally {this.resetCommonCaches();}}
}

// AbstractApplicationContext.class
protected ConfigurableListableBeanFactory obtainFreshBeanFactory() {// 刷新IoC容器this.refreshBeanFactory();// 获取Bean Factory对象 --》 已经完成了IoC的初始化操作return this.getBeanFactory();
}

// AbstractRefreshableApplicationContext.class
protected final void refreshBeanFactory() throws BeansException {if (this.hasBeanFactory()) {this.destroyBeans();this.closeBeanFactory();}try {// 创建Bean Factory对象 DefaultListableBeanFactoryDefaultListableBeanFactory beanFactory = this.createBeanFactory();beanFactory.setSerializationId(this.getId());this.customizeBeanFactory(beanFactory);// 加载 BeanDefinition -> <bean>this.loadBeanDefinitions(beanFactory);this.beanFactory = beanFactory;} catch (IOException var2) {throw new ApplicationContextException("I/O error parsing bean definition source for " + this.getDisplayName(), var2);}
}

protected DefaultListableBeanFactory createBeanFactory() {return new DefaultListableBeanFactory(this.getInternalParentBeanFactory());
}

// AbstractXmlApplicationContext.class
protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) throws BeansException, IOException {XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);beanDefinitionReader.setEnvironment(this.getEnvironment());beanDefinitionReader.setResourceLoader(this);beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this));this.initBeanDefinitionReader(beanDefinitionReader);this.loadBeanDefinitions(beanDefinitionReader);
}

// AbstractXmlApplicationContext.class
protected void loadBeanDefinitions(XmlBeanDefinitionReader reader) throws BeansException, IOException {Resource[] configResources = this.getConfigResources();if (configResources != null) {reader.loadBeanDefinitions(configResources);}String[] configLocations = this.getConfigLocations();if (configLocations != null) {reader.loadBeanDefinitions(configLocations);}}

// AbstractBeanDefinitionReader.class
public int loadBeanDefinitions(String... locations) throws BeanDefinitionStoreException {Assert.notNull(locations, "Location array must not be null");int count = 0;String[] var3 = locations;int var4 = locations.length;// 循环加载每个配置文件for(int var5 = 0; var5 < var4; ++var5) {String location = var3[var5];count += this.loadBeanDefinitions(location);}return count;
}

// AbstractBeanDefinitionReader.class
public int loadBeanDefinitions(String location, @Nullable Set<Resource> actualResources) throws BeanDefinitionStoreException {ResourceLoader resourceLoader = this.getResourceLoader();if (resourceLoader == null) {throw new BeanDefinitionStoreException("Cannot load bean definitions from location [" + location + "]: no ResourceLoader available");} else {int count;if (resourceLoader instanceof ResourcePatternResolver) {try {Resource[] resources = ((ResourcePatternResolver)resourceLoader).getResources(location);// 进入count = this.loadBeanDefinitions(resources);if (actualResources != null) {Collections.addAll(actualResources, resources);}if (this.logger.isTraceEnabled()) {this.logger.trace("Loaded " + count + " bean definitions from location pattern [" + location + "]");}return count;} catch (IOException var6) {throw new BeanDefinitionStoreException("Could not resolve bean definition resource pattern [" + location + "]", var6);}} else {Resource resource = resourceLoader.getResource(location);count = this.loadBeanDefinitions((Resource)resource);if (actualResources != null) {actualResources.add(resource);}if (this.logger.isTraceEnabled()) {this.logger.trace("Loaded " + count + " bean definitions from location [" + location + "]");}return count;}}
}

// XmlBeanDefinitionReader.class
public int loadBeanDefinitions(EncodedResource encodedResource) throws BeanDefinitionStoreException {Assert.notNull(encodedResource, "EncodedResource must not be null");if (this.logger.isTraceEnabled()) {this.logger.trace("Loading XML bean definitions from " + encodedResource);}Set<EncodedResource> currentResources = (Set)this.resourcesCurrentlyBeingLoaded.get();if (currentResources == null) {currentResources = new HashSet(4);this.resourcesCurrentlyBeingLoaded.set(currentResources);}if (!((Set)currentResources).add(encodedResource)) {throw new BeanDefinitionStoreException("Detected cyclic loading of " + encodedResource + " - check your import definitions!");} else {int var5;try {// 获取需要读取的配置文件的字节输入流InputStream inputStream = encodedResource.getResource().getInputStream();try {InputSource inputSource = new InputSource(inputStream);if (encodedResource.getEncoding() != null) {inputSource.setEncoding(encodedResource.getEncoding());}// 进入var5 = this.doLoadBeanDefinitions(inputSource, encodedResource.getResource());} finally {inputStream.close();}} catch (IOException var15) {throw new BeanDefinitionStoreException("IOException parsing XML document from " + encodedResource.getResource(), var15);} finally {((Set)currentResources).remove(encodedResource);if (((Set)currentResources).isEmpty()) {this.resourcesCurrentlyBeingLoaded.remove();}}return var5;}
}

// XmlBeanDefinitionReader.class
protected int doLoadBeanDefinitions(InputSource inputSource, Resource resource) throws BeanDefinitionStoreException {try {// 通过SAX加载配置文件 获取对于的Document对象Document doc = this.doLoadDocument(inputSource, resource);// 注册BeanDefinitionint count = this.registerBeanDefinitions(doc, resource);if (this.logger.isDebugEnabled()) {this.logger.debug("Loaded " + count + " bean definitions from " + resource);}return count;} catch (BeanDefinitionStoreException var5) {throw var5;} catch (SAXParseException var6) {throw new XmlBeanDefinitionStoreException(resource.getDescription(), "Line " + var6.getLineNumber() + " in XML document from " + resource + " is invalid", var6);} catch (SAXException var7) {throw new XmlBeanDefinitionStoreException(resource.getDescription(), "XML document from " + resource + " is invalid", var7);} catch (ParserConfigurationException var8) {throw new BeanDefinitionStoreException(resource.getDescription(), "Parser configuration exception parsing XML from " + resource, var8);} catch (IOException var9) {throw new BeanDefinitionStoreException(resource.getDescription(), "IOException parsing XML document from " + resource, var9);} catch (Throwable var10) {throw new BeanDefinitionStoreException(resource.getDescription(), "Unexpected exception parsing XML document from " + resource, var10);}
}

// XmlBeanDefinitionReader.class
public int registerBeanDefinitions(Document doc, Resource resource) throws BeanDefinitionStoreException {BeanDefinitionDocumentReader documentReader = this.createBeanDefinitionDocumentReader();int countBefore = this.getRegistry().getBeanDefinitionCount();// 注册documentReader.registerBeanDefinitions(doc, this.createReaderContext(resource));return this.getRegistry().getBeanDefinitionCount() - countBefore;
}

// DefaultBeanDefinitionDocumentReader.class
protected void doRegisterBeanDefinitions(Element root) {BeanDefinitionParserDelegate parent = this.delegate;this.delegate = this.createDelegate(this.getReaderContext(), root, parent);if (this.delegate.isDefaultNamespace(root)) {String profileSpec = root.getAttribute("profile");if (StringUtils.hasText(profileSpec)) {String[] specifiedProfiles = StringUtils.tokenizeToStringArray(profileSpec, ",; ");if (!this.getReaderContext().getEnvironment().acceptsProfiles(specifiedProfiles)) {if (this.logger.isDebugEnabled()) {this.logger.debug("Skipped XML bean definition file due to specified profiles [" + profileSpec + "] not matching: " + this.getReaderContext().getResource());}return;}}}// 解析之前操作this.preProcessXml(root);this.parseBeanDefinitions(root, this.delegate);// 解析之后的操作this.postProcessXml(root);this.delegate = parent;
}

// DefaultBeanDefinitionDocumentReader.class
protected void parseBeanDefinitions(Element root, BeanDefinitionParserDelegate delegate) {if (delegate.isDefaultNamespace(root)) {NodeList nl = root.getChildNodes();for(int i = 0; i < nl.getLength(); ++i) {Node node = nl.item(i);if (node instanceof Element) {Element ele = (Element)node;if (delegate.isDefaultNamespace(ele)) {// 默认的元素解析 <bean> <import> ...this.parseDefaultElement(ele, delegate);} else {// <aop> <dubbo> ...delegate.parseCustomElement(ele);}}}} else {delegate.parseCustomElement(root);}}

// DefaultBeanDefinitionDocumentReader.class
private void parseDefaultElement(Element ele, BeanDefinitionParserDelegate delegate) {if (delegate.nodeNameEquals(ele, "import")) {// <import>this.importBeanDefinitionResource(ele);} else if (delegate.nodeNameEquals(ele, "alias")) {// <alias>this.processAliasRegistration(ele);} else if (delegate.nodeNameEquals(ele, "bean")) {// <bean>this.processBeanDefinition(ele, delegate);} else if (delegate.nodeNameEquals(ele, "beans")) {// <beans>this.doRegisterBeanDefinitions(ele);}}

// DefaultBeanDefinitionDocumentReader.class
protected void processBeanDefinition(Element ele, BeanDefinitionParserDelegate delegate) {// 完成了<bean> 标签的解析BeanDefinitionHolder bdHolder = delegate.parseBeanDefinitionElement(ele);if (bdHolder != null) {bdHolder = delegate.decorateBeanDefinitionIfRequired(ele, bdHolder);try {// 注册BeanDefinitionReaderUtils.registerBeanDefinition(bdHolder, this.getReaderContext().getRegistry());} catch (BeanDefinitionStoreException var5) {this.getReaderContext().error("Failed to register bean definition with name '" + bdHolder.getBeanName() + "'", ele, var5);}this.getReaderContext().fireComponentRegistered(new BeanComponentDefinition(bdHolder));}}

// BeanDefinitionParserDelegate.class
@Nullable
public BeanDefinitionHolder parseBeanDefinitionElement(Element ele, @Nullable BeanDefinition containingBean) {String id = ele.getAttribute("id");String nameAttr = ele.getAttribute("name");List<String> aliases = new ArrayList();if (StringUtils.hasLength(nameAttr)) {String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, ",; ");aliases.addAll(Arrays.asList(nameArr));}String beanName = id;if (!StringUtils.hasText(id) && !aliases.isEmpty()) {beanName = (String)aliases.remove(0);if (this.logger.isTraceEnabled()) {this.logger.trace("No XML 'id' specified - using '" + beanName + "' as bean name and " + aliases + " as aliases");}}if (containingBean == null) {this.checkNameUniqueness(beanName, aliases, ele);}// 完成了<bean> --> BeanDefinition的转换AbstractBeanDefinition beanDefinition = this.parseBeanDefinitionElement(ele, beanName, containingBean);if (beanDefinition != null) {if (!StringUtils.hasText(beanName)) {try {if (containingBean != null) {beanName = BeanDefinitionReaderUtils.generateBeanName(beanDefinition, this.readerContext.getRegistry(), true);} else {beanName = this.readerContext.generateBeanName(beanDefinition);String beanClassName = beanDefinition.getBeanClassName();if (beanClassName != null && beanName.startsWith(beanClassName) && beanName.length() > beanClassName.length() && !this.readerContext.getRegistry().isBeanNameInUse(beanClassName)) {aliases.add(beanClassName);}}if (this.logger.isTraceEnabled()) {this.logger.trace("Neither XML 'id' nor 'name' specified - using generated bean name [" + beanName + "]");}} catch (Exception var9) {this.error(var9.getMessage(), ele);return null;}}String[] aliasesArray = StringUtils.toStringArray(aliases);return new BeanDefinitionHolder(beanDefinition, beanName, aliasesArray);} else {return null;}
}

// BeanDefinitionReaderUtils.class
public static void registerBeanDefinition(BeanDefinitionHolder definitionHolder, BeanDefinitionRegistry registry) throws BeanDefinitionStoreException {String beanName = definitionHolder.getBeanName();registry.registerBeanDefinition(beanName, definitionHolder.getBeanDefinition());String[] aliases = definitionHolder.getAliases();if (aliases != null) {String[] var4 = aliases;int var5 = aliases.length;for(int var6 = 0; var6 < var5; ++var6) {String alias = var4[var6];registry.registerAlias(beanName, alias);}}}

// DefaultListableBeanFactory.class 725行
this.beanDefinitionMap.put(beanName, beanDefinition);

DI过程

package com.gupaoedu;import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;@Configuration
public class JavaConfig {public static void main(String[] args) {ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");ac.getBean(Person.class);}}

// DefaultListableBeanFactory.class
@Nullable
private <T> T resolveBean(ResolvableType requiredType, @Nullable Object[] args, boolean nonUniqueAsNull) {// 核心代码NamedBeanHolder<T> namedBean = this.resolveNamedBean(requiredType, args, nonUniqueAsNull);if (namedBean != null) {return namedBean.getBeanInstance();} else {BeanFactory parent = this.getParentBeanFactory();if (parent instanceof DefaultListableBeanFactory) {return ((DefaultListableBeanFactory)parent).resolveBean(requiredType, args, nonUniqueAsNull);} else if (parent != null) {ObjectProvider<T> parentProvider = parent.getBeanProvider(requiredType);if (args != null) {return parentProvider.getObject(args);} else {return nonUniqueAsNull ? parentProvider.getIfUnique() : parentProvider.getIfAvailable();}} else {return null;}}
}

// DefaultListableBeanFactory.class
@Nullable
private <T> NamedBeanHolder<T> resolveNamedBean(ResolvableType requiredType, @Nullable Object[] args, boolean nonUniqueAsNull) throws BeansException {Assert.notNull(requiredType, "Required type must not be null");// 获取候选的类型的全路径字符串数组String[] candidateNames = this.getBeanNamesForType(requiredType);String[] var6;int var7;int var8;String beanName;if (candidateNames.length > 1) {List<String> autowireCandidates = new ArrayList(candidateNames.length);var6 = candidateNames;var7 = candidateNames.length;for(var8 = 0; var8 < var7; ++var8) {beanName = var6[var8];if (!this.containsBeanDefinition(beanName) || this.getBeanDefinition(beanName).isAutowireCandidate()) {autowireCandidates.add(beanName);}}if (!autowireCandidates.isEmpty()) {candidateNames = StringUtils.toStringArray(autowireCandidates);}}if (candidateNames.length == 1) {String beanName = candidateNames[0];return new NamedBeanHolder(beanName, this.getBean(beanName, requiredType.toClass(), args));} else {if (candidateNames.length > 1) {Map<String, Object> candidates = new LinkedHashMap(candidateNames.length);var6 = candidateNames;var7 = candidateNames.length;for(var8 = 0; var8 < var7; ++var8) {beanName = var6[var8];if (this.containsSingleton(beanName) && args == null) {// 创建实例的方法Object beanInstance = this.getBean(beanName);candidates.put(beanName, beanInstance instanceof NullBean ? null : beanInstance);} else {candidates.put(beanName, this.getType(beanName));}}String candidateName = this.determinePrimaryCandidate(candidates, requiredType.toClass());if (candidateName == null) {candidateName = this.determineHighestPriorityCandidate(candidates, requiredType.toClass());}if (candidateName != null) {Object beanInstance = candidates.get(candidateName);if (beanInstance == null || beanInstance instanceof Class) {beanInstance = this.getBean(candidateName, requiredType.toClass(), args);}return new NamedBeanHolder(candidateName, beanInstance);}if (!nonUniqueAsNull) {throw new NoUniqueBeanDefinitionException(requiredType, candidates.keySet());}}return null;}
}

// AbstractBeanFactory.class
public Object getBean(String name) throws BeansException {return this.doGetBean(name, (Class)null, (Object[])null, false);
}

// AbstractBeanFactory.class
protected <T> T doGetBean(String name, @Nullable Class<T> requiredType, @Nullable Object[] args, boolean typeCheckOnly) throws BeansException {String beanName = this.transformedBeanName(name);Object sharedInstance = this.getSingleton(beanName);Object bean;if (sharedInstance != null && args == null) {if (this.logger.isTraceEnabled()) {if (this.isSingletonCurrentlyInCreation(beanName)) {this.logger.trace("Returning eagerly cached instance of singleton bean '" + beanName + "' that is not fully initialized yet - a consequence of a circular reference");} else {this.logger.trace("Returning cached instance of singleton bean '" + beanName + "'");}}bean = this.getObjectForBeanInstance(sharedInstance, name, beanName, (RootBeanDefinition)null);} else {if (this.isPrototypeCurrentlyInCreation(beanName)) {throw new BeanCurrentlyInCreationException(beanName);}BeanFactory parentBeanFactory = this.getParentBeanFactory();if (parentBeanFactory != null && !this.containsBeanDefinition(beanName)) {String nameToLookup = this.originalBeanName(name);if (parentBeanFactory instanceof AbstractBeanFactory) {return ((AbstractBeanFactory)parentBeanFactory).doGetBean(nameToLookup, requiredType, args, typeCheckOnly);}if (args != null) {return parentBeanFactory.getBean(nameToLookup, args);}if (requiredType != null) {return parentBeanFactory.getBean(nameToLookup, requiredType);}return parentBeanFactory.getBean(nameToLookup);}if (!typeCheckOnly) {this.markBeanAsCreated(beanName);}try {RootBeanDefinition mbd = this.getMergedLocalBeanDefinition(beanName);this.checkMergedBeanDefinition(mbd, beanName, args);String[] dependsOn = mbd.getDependsOn();String[] var11;if (dependsOn != null) {var11 = dependsOn;int var12 = dependsOn.length;for(int var13 = 0; var13 < var12; ++var13) {String dep = var11[var13];if (this.isDependent(beanName, dep)) {throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Circular depends-on relationship between '" + beanName + "' and '" + dep + "'");}this.registerDependentBean(dep, beanName);try {this.getBean(dep);} catch (NoSuchBeanDefinitionException var24) {throw new BeanCreationException(mbd.getResourceDescription(), beanName, "'" + beanName + "' depends on missing bean '" + dep + "'", var24);}}}if (mbd.isSingleton()) {sharedInstance = this.getSingleton(beanName, () -> {try {// 进入核心方法return this.createBean(beanName, mbd, args);} catch (BeansException var5) {this.destroySingleton(beanName);throw var5;}});bean = this.getObjectForBeanInstance(sharedInstance, name, beanName, mbd);} else if (mbd.isPrototype()) {var11 = null;Object prototypeInstance;try {this.beforePrototypeCreation(beanName);prototypeInstance = this.createBean(beanName, mbd, args);} finally {this.afterPrototypeCreation(beanName);}bean = this.getObjectForBeanInstance(prototypeInstance, name, beanName, mbd);} else {String scopeName = mbd.getScope();if (!StringUtils.hasLength(scopeName)) {throw new IllegalStateException("No scope name defined for bean ´" + beanName + "'");}Scope scope = (Scope)this.scopes.get(scopeName);if (scope == null) {throw new IllegalStateException("No Scope registered for scope name '" + scopeName + "'");}try {Object scopedInstance = scope.get(beanName, () -> {this.beforePrototypeCreation(beanName);Object var4;try {var4 = this.createBean(beanName, mbd, args);} finally {this.afterPrototypeCreation(beanName);}return var4;});bean = this.getObjectForBeanInstance(scopedInstance, name, beanName, mbd);} catch (IllegalStateException var23) {throw new BeanCreationException(beanName, "Scope '" + scopeName + "' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton", var23);}}} catch (BeansException var26) {this.cleanupAfterBeanCreationFailure(beanName);throw var26;}}if (requiredType != null && !requiredType.isInstance(bean)) {try {T convertedBean = this.getTypeConverter().convertIfNecessary(bean, requiredType);if (convertedBean == null) {throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());} else {return convertedBean;}} catch (TypeMismatchException var25) {if (this.logger.isTraceEnabled()) {this.logger.trace("Failed to convert bean '" + name + "' to required type '" + ClassUtils.getQualifiedName(requiredType) + "'", var25);}throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());}} else {return bean;}
}

// AbstractAutowireCapableBeanFactory.class
protected Object createBean(String beanName, RootBeanDefinition mbd, @Nullable Object[] args) throws BeanCreationException {if (this.logger.isTraceEnabled()) {this.logger.trace("Creating instance of bean '" + beanName + "'");}RootBeanDefinition mbdToUse = mbd;Class<?> resolvedClass = this.resolveBeanClass(mbd, beanName, new Class[0]);if (resolvedClass != null && !mbd.hasBeanClass() && mbd.getBeanClassName() != null) {mbdToUse = new RootBeanDefinition(mbd);mbdToUse.setBeanClass(resolvedClass);}try {mbdToUse.prepareMethodOverrides();} catch (BeanDefinitionValidationException var9) {throw new BeanDefinitionStoreException(mbdToUse.getResourceDescription(), beanName, "Validation of method overrides failed", var9);}Object beanInstance;try {beanInstance = this.resolveBeforeInstantiation(beanName, mbdToUse);if (beanInstance != null) {return beanInstance;}} catch (Throwable var10) {throw new BeanCreationException(mbdToUse.getResourceDescription(), beanName, "BeanPostProcessor before instantiation of bean failed", var10);}try {beanInstance = this.doCreateBean(beanName, mbdToUse, args);if (this.logger.isTraceEnabled()) {this.logger.trace("Finished creating instance of bean '" + beanName + "'");}return beanInstance;} catch (ImplicitlyAppearedSingletonException | BeanCreationException var7) {throw var7;} catch (Throwable var8) {throw new BeanCreationException(mbdToUse.getResourceDescription(), beanName, "Unexpected exception during bean creation", var8);}
}

// AbstractAutowireCapableBeanFactory.class
protected Object doCreateBean(String beanName, RootBeanDefinition mbd, @Nullable Object[] args) throws BeanCreationException {BeanWrapper instanceWrapper = null;if (mbd.isSingleton()) {instanceWrapper = (BeanWrapper)this.factoryBeanInstanceCache.remove(beanName);}if (instanceWrapper == null) {// 创建实例的方法instanceWrapper = this.createBeanInstance(beanName, mbd, args);}Object bean = instanceWrapper.getWrappedInstance();Class<?> beanType = instanceWrapper.getWrappedClass();if (beanType != NullBean.class) {mbd.resolvedTargetType = beanType;}Object var7 = mbd.postProcessingLock;synchronized(mbd.postProcessingLock) {if (!mbd.postProcessed) {try {this.applyMergedBeanDefinitionPostProcessors(mbd, beanType, beanName);} catch (Throwable var17) {throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Post-processing of merged bean definition failed", var17);}mbd.postProcessed = true;}}boolean earlySingletonExposure = mbd.isSingleton() && this.allowCircularReferences && this.isSingletonCurrentlyInCreation(beanName);if (earlySingletonExposure) {if (this.logger.isTraceEnabled()) {this.logger.trace("Eagerly caching bean '" + beanName + "' to allow for resolving potential circular references");}this.addSingletonFactory(beanName, () -> {return this.getEarlyBeanReference(beanName, mbd, bean);});}Object exposedObject = bean;try {this.populateBean(beanName, mbd, instanceWrapper);exposedObject = this.initializeBean(beanName, exposedObject, mbd);} catch (Throwable var18) {if (var18 instanceof BeanCreationException && beanName.equals(((BeanCreationException)var18).getBeanName())) {throw (BeanCreationException)var18;}throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Initialization of bean failed", var18);}if (earlySingletonExposure) {Object earlySingletonReference = this.getSingleton(beanName, false);if (earlySingletonReference != null) {if (exposedObject == bean) {exposedObject = earlySingletonReference;} else if (!this.allowRawInjectionDespiteWrapping && this.hasDependentBean(beanName)) {String[] dependentBeans = this.getDependentBeans(beanName);Set<String> actualDependentBeans = new LinkedHashSet(dependentBeans.length);String[] var12 = dependentBeans;int var13 = dependentBeans.length;for(int var14 = 0; var14 < var13; ++var14) {String dependentBean = var12[var14];if (!this.removeSingletonIfCreatedForTypeCheckOnly(dependentBean)) {actualDependentBeans.add(dependentBean);}}if (!actualDependentBeans.isEmpty()) {throw new BeanCurrentlyInCreationException(beanName, "Bean with name '" + beanName + "' has been injected into other beans [" + StringUtils.collectionToCommaDelimitedString(actualDependentBeans) + "] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example.");}}}}try {this.registerDisposableBeanIfNecessary(beanName, bean, mbd);return exposedObject;} catch (BeanDefinitionValidationException var16) {throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Invalid destruction signature", var16);}
}