详解Spring中Bean的加载的方法

详解Spring中Bean的加载的方法

之前写过bean的解析，这篇来讲讲bean的加载，加载要比bean的解析复杂些，从之前的例子开始.

Spring中加载一个bean的方式：

TestBean bean = factory.getBean("testBean");

来看看getBean(String name)方法源码，

@Override

public Object getBean(String name) throws BeansException {

return doGetBean(name, null, null, false);

}

该getBean(String name)方法位于AbstractBeanFactory抽象类中，AbstractBeanFactory与XmlBeanFactory类关系可以看下图：

接下去跟进doGetBean()方法源码：

protected T doGetBean(

final String name, final Class requiredType, final Object[] args, boolean typeCheckOnly)

throws BeansException {

// 提取beanName

final String beanName = transformedBeanName(name);

Object bean;

// 试着从缓存或实例工厂中获取

Object sharedInstance = getSingleton(beanName);

if (sharedInstance != null && args == null) {

if (logger.isDebugEnabled()) {

if (isSingletonCurrentlyInCreation(beanName)) {

logger.debug("Returning eagerly cached instance of singleton bean '" + beanName +

"' that is not fully initialized yet - a consequence of a circular reference");

}

else {

logger.debug("Returning cached instance of singleton bean '" + beanName + "'");

}

}

// 返回实例，有时存在如BeanFactory这样情况时并不是直接返回实例本身而是返回指定方法返回的实例

bean = getObjectForBeanInstance(sharedInstance, name, beanName, null);

}

else {

// Fail if we're already creating this bean instance:

// We're assumably within a circular reference.

if (isPrototypeCurrentlyInCreation(beanName)) {

throw new BeanCurrentlyInCreationException(beanName);

}

// Check if bean definition exists in this factory.

BeanFactory parentBeanFactory = getParentBeanFactory();

// 如果在所有已经加载的类中没有beanName则会尝试从parentBeanFactory中检测

if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {

// Not found -> check parent.

String nameToLookup = originalBeanName(name);

// 到BeanFactory查找

if (args != null) {

// Delegation to parent with explicit args.

return (T) parentBeanFactory.getBean(nameToLookup, args);

}

else {

// No args -> delegate to standard getBean method.

return parentBeanFactory.getBean(nameToLookup, requiredType);

}

}

// 如果不是只做类型检查则是创建bean

if (!typeCheckOnly) {

markBeanAsCreated(beanName);

}

try {

// 将存储XML配置文件的GernericBeanDefinition转换成RootBeanDefinition，如果BeanName是子Bean的话会合并父类的相关属性

final RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);

checkMergedBeanDefinition(mbd, beanName, args);

// Guarantee initialization of beans that the current bean depends on.

String[] dependsOn = mbd.getDependsOn();

// 如果存在依赖的话要递归实例化依赖的bean

if (dependsOn != null) {

for (String dependsOnBean :OqRlMsbYc dependsOn) {

if (isDependent(beanName, dependsOnBean)) {

throw new BeanCreationException(mbd.getResourceDescription(), beanName,

"Circular depends-on relationship between '" + beanName + "' and '" + dependsOnBean + "'");

}

registerDependentBean(dependsOnBean, beanName);

getBean(dependsOnBean);

}

}

// Create bean instance.

// 依赖的bean实例化完后就可以实例化mbd了

if (mbd.isSingleton()) {

sharedInstance = getSingleton(beanName, new ObjectFactory

@Override

public Object getObject() throws BeansException {

try {

return createBean(beanName, mbd, args);

}

catch (BeansException ex) {

// Explicitly remove instance from singleton cache: It might have been put there

// eagerly by the creation process, to allow for circular reference resolution.

// Also remove any beans that received a temporary reference to the bean.

destroySingleton(beanName);

throw ex;

}

}

});

bean = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);

}

else if (mbd.isPrototype()) {

// It's a prototype -> create a new instance.

Object prototypeInstance = null;

try {

beforePrototypeCreation(beanName);

prototypeInstance = createBean(beanName, mbd, args);

}

finally {

afterPrototypeCreation(beanName);

}

bean = getObjectForBeanInstance(prototypeInstance, name, beanName, mbd);

}

else {

// 在对应的scope上实例化bean

String scopeName = mbd.getScope();

final Scope scope = this.scopes.get(scopeName);

if (scope == null) {

throw new IllegalStateException("No Scope registered for scope '" + scopeName + "'");

}

try {

Object scopedInstance = scope.get(beanName, new ObjectFactory

@Override

public Object getObject() throws BeansException {

beforePrototypeCreation(beanName);

try {

return createBean(beanName, mbd, args);

}

finally {

afterPrototypeCreation(beanName);

}

}

});

bean = getObjectForBeanInstance(scopedInstance, name, beanName, mbd);

}

catch (IllegalStateException ex) {

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",

ex);

}

}

}

catch (BeansException ex) {

cleanupAfterBeanCreationFailure(beanName);

throw ex;

}

}

// 检查需要的类型是否符合实例bean的实际类型

if (requiredType != null && bean != null && !requiredType.isAssignableFrom(bean.getClass())) {

try {

return getTypeConverter().convertIfNecessary(bean, requiredType);

}

catch (TypeMismatchException ex) {

if (logger.isDebugEnabled()) {

logger.debug("Failed to convert bean '" + name + "' to required type [" +

ClassUtils.getQualifiedName(requiredType) + "]", ex);

}

throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());

}

}

return (T) bean;

}

整个bean加载的过程步骤相对繁琐，主要步骤有以下几点：

1、转换beanName

要知道平时开发中传入的参数name可能只是别名，也可能是FactoryBean，所以需要进行解析转换，一般会进行以下解析：

（1）消除修饰符，比如name="&test"，会去除&使name="test"；

（2）取alias表示的最后的beanName，比如别名test01指向名称为test02的bean则返回test02。

2、从缓存中加载实例

实例在Spring的同一个容器中只会被创建一次，后面再想获取该bean时，就会尝试从缓存中获取；如果获取不到的话再从singletonFactories中加载。

3、实例化bean

缓存中记录的bean一般只是最原始的bean状态，这时就需要对bean进行实例化。如果得到的是bean的原始状态，但又要对bean进行处理，这时真正需要的是工厂bean中定义的factory-method方法中返回的bean，上面源码中的getObjectForBeanInstance就是来完成这个工作的。

4、检测parentBeanFacotory

从源码可以看出如果缓存中没有数据会转到父类工厂去加载，源码中的!containsBeanDefinition(beanName)就是检测如果当前加载的xml配置文件中不包含beanName所对应的配置，就只能到parentBeanFacotory去尝试加载bean。

5、存储XML配置文件的GernericBeanDefinition转换成RootBeanDefinition之前的文章介绍过XML配置文件中读取到的bean信息是存储在GernericBeanDefinition中的，但Bean的后续处理是针对于RootBeanDefinition的，所以需要转换后才能进行后续操作。

6、初始化依赖的bean

这里应该比较好理解，就是bean中可能依赖了其他bean属性，在初始化bean之前会先初始化这个bean所依赖的bean属性。

7、创建bean

Spring容器根据不同scope创建bean实例。

整个流程就是如此，下面会讲解一些重要步骤的源码。

上面有提到，单例在Spring中的同一容器中只会被创建一次，后面再获取bean的话会直接从缓存中获取，这里是尝试加载，先从缓存中加载，再次就是从singletonFactories中加载；因为在bean中可能会在依赖注入，要避免循环依赖，Spring创建bean时会不等bean创建完成就会将创建该bean的ObjectFactory提前曝光加入到缓存中，但下一个bean创建时要依赖上个bean的话，就直接使用ObjectFacotry。

@Override

public Object getSingleton(String beanName) {

return getSingleton(beanName, true); // true表示允许早期依赖

}

protected Object getSingleton(String beanName, boolean allowEarlyReference) {

// 尝试从缓存获取实例

Object singletonObject = this.singletonObjects.get(beanName);

if (singletonObject == null && isSingletonCurrentlyInCreation(beanName)) {

synchronized (this.singletonObjects) {

// 若该bean正在加载则不处理

singletonObject = this.earlySingletonObjects.get(beanName);

if (singletonObject == null && allowEarlyReference) {

ObjectFactory> singletonFactory = this.singletonFactories.get(beanName);

if (singletonFactory != null) {

singletonObject = singletonFactory.getObject();

// 存入到缓存中

this.earlySingletonObjects.put(beanName, singletonObject);

this.singletonFactories.remove(beanName);

}

}

}

}

return (singletonObject != NULL_OBJECT ? singletonObject : null);

}

/* 这两个方法在DefaultSingletonBeanRegistry类中 */

从源码可以看出这个方法先尝试从singletonObjects中获取实例，如果获取不到值就从earlySingletonObject中去获取，如果再获取不到的话则到singletonFactories里获取beanName对应的ObjectFactory，再调用这个ObjectFactory的getObject来创建bean，并放到earlySingletonObject中，并且从singletonFactories里remove掉这个ObjectFactory。这里有几个存储bean的不同map：

-singletonObjects：保存BeanName和创建bean实例之间的关系。

-singletonFactories：保存BeanName和创建bean实例的工厂之间的关系。

-earlySingletonObject：保存BeanName和创建bean实例之间的关系，与-singletonObjects不同的是当一个单例bean被放到里面后，那当bean在创建过程中，就可以通过getBean方法获取到，可以用来检测循环引用。

-registeredSingletons：保存当前所有已注册的bean。

如果上面缓存中不存在已经加载的单例bean就要重新开始bean的加载过程了，Spring中使用getSingleton重载方法实现bean的加载过程。

public Object getSingleton(String beanName, ObjectFactory> singletonFactory) {

Assert.notNull(beanName, "'beanName' must not be null");

synchronized (this.singletonObjects) {

// 先检查bean是否已经加载

Object singletonObject = this.singletonObjects.get(beanName);

// 如果空才进行singleton的bean的初始化

if (singletonObject == null) {

if (this.singletonsCurrentlyInDestruction) {

throw new BeanCreationNotAllowedException(beanName,

"Singleton bean creation not allowed while the singletons of this factory are in destruction " +

"(Do not request a bean from a BeanFactory in a destroy method implementation!)");

}

if (logger.isDebugEnabled()) {

logger.debug("Creating shared instance of singleton bean '" + beanName + "'");

}

beforeSingletonCreation(beanName);

boolean newSingleton = false;

boolean recordSuppressedExceptions = (this.suppressedExceptions == null);

if (recordSuppressedExceptions) {

this.suppressedExceptions = new LinkedHashSet();

}

try {

// 初始化bean

singletonObject = singletonFactory.getObject();

newSingleton = true;

}

catch (IllegalStateException ex) {

// Has the singleton object implicitly appeared in the meantime ->

// if yes, proceed with it since the exception indicates that state.

singletonObject = this.singletonObjects.get(beanName);

if (singletonObject == null) {

throw ex;

}

}

catch (BeanCreationException ex) {

if (recordSuppressedExceptions) {

for (Exception suppressedException : this.suppressedExceptions) {

ex.addRelatedCause(suppressedException);

}

}

throw ex;

}

finally {

if (recordSuppressedExceptions) {

this.suppressedExceptions = null;

}

afterSingletonCreation(beanName);

}

if (newSingleton) {

// 存入缓存

addSingleton(beanName, singletonObject);

}

}

return (singletonObject != NULL_OBJECT ? singletonObject : null);

}

}

这段代码使用了回调方法，使程序可以在单例创建的前后做一些准备及处理操作，真正的获取单例bean的方法其实并不是在这个方法实现的，而是在ObjectFactory类型的实例singletonFactory中实现的。

下面准备创建bean

看看createBean()方法源码（该方法在AbstractAutowireCapableBeanFactory类中）：

protected Object createBean(final String beanName, final RootBeanDefinition mbd, final Object[] args)

throws BeanCreationException {

if (logger.isDebugEnabled()) {

logger.debug("Creating instance of bean '" + beanName + "'");

}

// 锁定class，根据设置的class属性或根据className来解析Class

resolveBeanClass(mbd, beanName);

// 验证和准备覆盖的方法

try {

mbd.prepareMethodOverrides();

}

catch (BeanDefinitionValidationException ex) {

throw new BeanDefinitionStoreException(mbd.getResourceDescription(),

beanName, "Validation of method overrides failed", ex);

}

try {

// 用BeanPostProcessors返回代理来替代真正的实例

Object bean = resolveBeforeInstantiation(beanName, mbd);

if (bean != null) {

return bean;

}

}

catch (Throwable ex) {

throw new BeanCreationException(mbd.getResourceDescription(), beanName,

"BeanPostProcessor before instantiation of bean failed", ex);

}

Object beanInstance = doCreateBean(beanName, mbd, args);

if (logger.isDebugEnabled()) {

logger.debug("Finished creating instance of bean '" + beanName + "'");

}

return beanInstance;

}

从createBean()方法源码可以看出主要做了以下操作：

根据设置的class属性或根据className来解析Class；

对覆盖进行标记并验证，在Spring配置中是存在lookup-mothod和replace-method的，这两个配置的加载其实就是将配置统一存放在BeanDefinition中的methodOverrides属性里，这个方法的操作也就是针对于这两个配置的；

应用初始化前的后处理器，最后创建bean。

在createBean()方法里执行完resolveBeforeInstantiation方法后，如果创建了代理且不为空的话就直接返回，否则需要进行常规bean的创建，这个创建过程是在doCreateBean中完成的，跟进源码：

protected Object doCreateBean(final String beanName, final RootBeanDefinition mbd, final Object[] args) {

// Instantiate the bean.

BeanWrapper instanceWrapper = null;

if (mbd.isSingleton()) {

instanceWrapper = this.factoryBeanInstanceCache.remove(beanName);

}

if (instanceWrapper == null) {

// 根据指定bean使用相应策略创建实例

instanceWrapper = createBeanInstance(beanName, mbd, args);

}

final Object bean = (instanceWrapper != null ? instanceWrapper.getWrappedInstance() : null);

Class> beanType = (instanceWrapper != null ? instanceWrapper.getWrappedClass() : null);

// Allow post-processors to modify the merged bean definition.

synchronized (mbd.postProcessingLock) {

if (!mbd.postProcessed) {

applyMergedBeanDefinitionPostProcessors(mbd, beanType, beanName);

mbd.postProcessed = true;

}

}

// 检测循环依赖，是否需要提早曝光

boolean earlySingletonExposure = (mbd.isSingleton() && this.allowCircularReferences &&

isSingletonCurrentlyInCreation(beanName));

if (earlySingletonExposure) {

if (logger.isDebugEnabled()) {

logger.debug("Eagerly caching bean '" + beanName +

"' to allow for resolving potential circular references");

}

// 避免循环依赖，可以在bean初始化完成前将创建实例的ObjectFactory加入工厂

addSingletonFactory(beanName, new ObjectFactory

@Override

public Object getObject() throws BeansException {

// 对bean再次依赖引用

// AOP也是在这里将advice动态织入bean中，若没有则直接返回bean，不做处理

return getEarlyBeanReference(beanName, mbd, bean);

}

});

}

// Initialize the bean instance.

Object exposedObject = bean;

try {

// 填充bean，注入属性值，如果存在依赖于其他bean的属性，会递归初始化

populateBean(beanName, mbd, instanceWrapper);

if (exposedObject != null) {

// 调用初始化方法

exposedObject = initializeBean(beanName, exposedObject, mbd);

}

}

catch (Throwable ex) {

if (ex instanceof BeanCreationException && beanName.equals(((BeanCreationException) ex).getBeanName())) {

throw (BeanCreationException) ex;

}

else {

throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Initialization of bean failed", ex);

}

}

if (earlySingletonExposure) {

Object earlySingletonReference = getSingleton(beanName, false);

// earlySingletonReference只有在检测到有循环依赖的情况下才会不为空

if (earlySingletonReference != null) {

if (exposedhttp://Object == bean) {

exposedObject = earlySingletonReference;

}

else if (!this.allowRawInjectionDespiteWrapping && hasDependentBean(beanName)) {

String[] dependentBeans = getDependentBeans(beanName);

Set actualDependentBeans = new LinkedHashSet(dependentBeans.length);

for (String dependentBean : dependentBeans) {

// 检测依赖

if (!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 " +

"'getBeanNamesOfType' with the 'allowEagerInit' flag turned off, for example.");

}

}

}

}

// Register bean as disposable.

try {

// 依据scopse注册bean

registerDisposableBeanIfNecessary(beanName, bean, mbd);

}

catch (BeanDefinitionValidationException ex) {

throw new BeanCreationException(mbd.getResourceDescription(), beanName, "Invalid destruction signature", ex);

}

return exposedObject;

}

上面源码完成的操作可以概括为以下几点：

开始是单例的话要先清除缓存；

实例化bean，将BeanDefinition转换为BeanWrapper；

使用MergedBeanDefinitionPostProcessor，Autowired注解就是通过此方法实现类型的预解析；

解决循环依赖问题；

填充属性，将属性填充到bean实例中；

注册DisposableBean；

创建完成并返回

接下来创建bean实例，看createBeanInstance()方法：

protected BeanWrapper createBeanInstance(String beanName, RootBeanDefinition mbd, Object[] args) {

// 解析class

Class> beanClass = resolveBeanClass(mbd, beanName);

if (beanClass != null && !Modifier.isPublic(beanClass.getModifiers()) && !mbd.isNonPublicAccessAllowed()) {

throw new BeanCreationException(mbd.getResourceDescription(), beanName,

"Bean class isn't public, and non-public access not allowed: " + beanClass.getName());

}

// 若工厂方法不为空则使用工厂方法初始化

if (mbd.getFactoryMethodName() != null) {

return instantiateUsingFactoryMethod(beanName, mbd, args);

}

// Shortcut when re-creating the same bean...

boolean resolved = false;

boolean autowireNecessary = false;

if (args == null) {

synchronized (mbd.constructorArgumentLock) {

if (mbd.resolvedConstructorOrFactoryMethod != null) {

resolved = true;

autowireNecessary = mbd.constructorArgumentsResolved;

}

}

}

// 如果已经解析过则使用解析好的构造方法不需要再次锁定

if (resolved) {

if (autowireNecessary) {

// 构造方法自动注入

return autowireConstructor(beanName, mbd, null, null);

}

else {

// 使用默认构造方法

return instantiateBean(beanName, mbd);

}

}

// 根据参数解析构造方法

Constructor>[] ctors = determineConstructorsFromBeanPostProcessors(beanClass, beanName);

if (ctors != null ||

mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_CONSTRUCTOR ||

mbd.hasConstructorArgumentValues() || !ObjectUtils.isEmpty(args)) {

return autowireConstructor(beanName, mbd, ctors, args);

}

// No special handling: simply use no-arg constructor.

return instantiateBean(beanName, mbd);

}

可以看出如果在RootBeanDefinition中存在factoryMethodName属性，或者说配置文件中配置了factory-method，那么Spring会尝试使用instantiateUsingFactoryMethod(beanName, mbd, args)方法根据RootBeanDefinition中的配置生成bean实例。

再解析构造方法并进行实例化，Spring会根据参数及类型判断使用哪个构造方法再进行实例化。判断调用哪个构造方法的过程会采用缓存机制，如果已经解析过则不需要重复解析而是从RootBeanDefinition中的属性resolvedConstructorOrFactoryMethod缓存的值去取，不然则需要再次解析。

创建bean后接下来就进行属性注入，属性注入的操作在populateBean()方法中，跟进源码：

protected void populateBean(String beanName, RootBeanDefinition mbd, BeanWrapper bw) {

PropertyValues pvs = mbd.getPropertyValues();

if (bw == null) {

if (!pvs.isEmpty()) {

throw new BeanCreationException(

mbd.getResourceDescription(), beanName, "Cannot apply property values to null instance");

}

else {

// Skip property population phase for null instance.

return;

}

}

// Give any InstantiationAwareBeanPostProcessors the opportunity to modify the

// state of the bean before properties are set. This can be used, for example,

// to support styles of field injection.

boolean continueWithPropertyPopulation = true;

if (!mbd.isSynthetic() && hasInstantiationAwareBeanPostProcessors()) {

for (BeanPostProcessor bp : getBeanPostProcessors()) {

if (bp instanceof InstantiationAwareBeanPostProcessor) {

InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;

if (!ibp.postProcessAfterInstantiation(bw.getWrappedInstance(), beanName)) {

continueWithPropertyPopulation = false;

break;

}

}

}

}

if (!continueWithPropertyPopulation) {

return;

}

if (mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_BY_NAME ||

mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_BY_TYPE) {

MutablePropertyValues newPvs = new MutablePropertyValues(pvs);

// Add property values based on autowire by name if applicable.

if (mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_BY_NAME) {

autowireByName(beanName, mbd, bw, newPvs);

}

// Add property values based on autowire by type if applicable.

if (mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_BY_TYPE) {

autowireByType(beanName, mbd, bw, newPvs);

}

pvs = newPvs;

}

boolean hasInstAwareBpps = hasInstantiationAwareBeanPostProcessors();

boolean needsDepCheck = (mbd.getDependencyCheck() != RootBeanDefinition.DEPENDENCY_CHECK_NONE);

if (hasInstAwareBpps || needsDepCheck) {

PropertyDescriptor[] filteredPds = filterPropertyDescriptorsForDependencyCheck(bw, mbd.allowCaching);

if (hasInstAwareBpps) {

for (BeanPostProcessor bp : getBeanPostProcessors()) {

if (bp instanceof InstantiationAwareBeanPostProcessor) {

InstantiationAwareBeanPostProcessor ibp = (InstantiationAwareBeanPostProcessor) bp;

pvs = ibp.postProcessPropertyValues(pvs, filteredPds, bw.getWrappedInstance(), beanName);

if (pvs == null) {

return;

}

}

}

}

if (needsDepCheck) {

checkDependencies(beanName, mbd, filteredPds, pvs);

}

}

applyPropertyValues(beanName, mbd, bw, pvs);

}

在populateBean方法的中的主要处理流程：

InstantiationAwareBeanPostProcessor处理器的postProcessAfterInstantiation方法控制程序是否继续填充属性；

根据注入类型提取依赖的bean，并存入PropertyValues中；

应用InstantiationAwareBeanPostProcessor处理器的postProcessPropertyValues方法对属性在填充前再次处理，主要还是验证属性；

将所有PropertyValues中的属性填充到BeanWrapper中。

最后初始化bean

学过Spring的都知道bean配置时有一个init-method属性，这个属性的作用是在bean实例化前调用init-method指定的方法进行需要的实例化操作，现在就进入这个方法了；Spring中程序已经执行过bean的实例化，并且进行了属性的填充，而就在这时将会调用用户设定的初始化方法。

protected Object initializeBean(final String beanName, final Object bean, RootBeanDefinition mbd) {

if (System.getSecurityManager() != null) {

AccessController.doPrivileged(new PrivilegedAction

@Override

public Object run() {

invokeAwareMethods(beanName, bean);

return null;

}

}, getAccessControlContext());

}

else {

// 特殊bean处理

invokeAwareMethods(beanName, bean);

}

Object wrappedBean = bean;

if (mbd == null || !mbd.isSynthetic()) {

wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);

}

try {

invokeInitMethods(beanName, wrappedBean, mbd);

}

catch (Throwable ex) {

throw new BeanCreationException(

(mbd != null ? mbd.getResourceDescription() : null),

beanName, "Invocation of init method failed", ex);

}

if (mbd == null || !mbd.isSynthetic()) {

wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);

}

return wrappedBean;

}

最后加载完Bean并执行完初始化操作后，一个bean的加载基本就结束了。

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