AbstractBeanFactory的getBean方法(转载)

 

public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport implements ConfigurableBeanFactory {

　　/** Parent bean factory, for bean inheritance support */
　　private BeanFactory parentBeanFactory;

　　/** ClassLoader to resolve bean class names with, if necessary */
　　private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();

　　/** ClassLoader to temporarily resolve bean class names with, if necessary */
　　private ClassLoader tempClassLoader;

　　/** Whether to cache bean metadata or rather reobtain it for every access */
　　private boolean cacheBeanMetadata = true;

　　/** Resolution strategy for expressions in bean definition values */
　　private BeanExpressionResolver beanExpressionResolver;

　　/** Spring ConversionService to use instead of PropertyEditors */
　　private ConversionService conversionService;

　　/** Custom PropertyEditorRegistrars to apply to the beans of this factory */
　　private final Set<PropertyEditorRegistrar> propertyEditorRegistrars = new LinkedHashSet<>(4);

　　/** A custom TypeConverter to use, overriding the default PropertyEditor mechanism */
　　private TypeConverter typeConverter;

　　/** Custom PropertyEditors to apply to the beans of this factory */
　　private final Map<Class<?>, Class<? extends PropertyEditor>> customEditors = new HashMap<>(4);

　　/** String resolvers to apply e.g. to annotation attribute values */
　　private final List<StringValueResolver> embeddedValueResolvers = new LinkedList<>();

　　/** BeanPostProcessors to apply in createBean */
　　private final List<BeanPostProcessor> beanPostProcessors = new ArrayList<>();

　　/** Indicates whether any InstantiationAwareBeanPostProcessors have been registered */
　　private boolean hasInstantiationAwareBeanPostProcessors;

　　/** Indicates whether any DestructionAwareBeanPostProcessors have been registered */
　　private boolean hasDestructionAwareBeanPostProcessors;

　　/** Map from scope identifier String to corresponding Scope */
　　private final Map<String, Scope> scopes = new LinkedHashMap<>(8);

　　/** Security context used when running with a SecurityManager */
　　private SecurityContextProvider securityContextProvider;

　　/** Map from bean name to merged RootBeanDefinition */
　　private final Map<String, RootBeanDefinition> mergedBeanDefinitions = new ConcurrentHashMap<>(256);

　　/** Names of beans that have already been created at least once */
　　private final Set<String> alreadyCreated = Collections.newSetFromMap(new ConcurrentHashMap<>(256));

　　/** Names of beans that are currently in creation */
　　private final ThreadLocal<Object> prototypesCurrentlyInCreation = new NamedThreadLocal<>("Prototype beans currently in creation");

　　/**
　　* Create a new AbstractBeanFactory.
　　*/
　　public AbstractBeanFactory() {
　　}

　　/**
　　* Create a new AbstractBeanFactory with the given parent.
　　* @param parentBeanFactory parent bean factory, or {@code null} if none
　　* @see #getBean
　　*/
　　public AbstractBeanFactory(BeanFactory parentBeanFactory) {
　　this.parentBeanFactory = parentBeanFactory;
　　}

　　//---------------------------------------------------------------------
　　// Implementation of BeanFactory interface
　　//---------------------------------------------------------------------

　　@Override
　　public Object getBean(String name) throws BeansException {
　　return doGetBean(name, null, null, false);
　　}

　　@Override
　　public <T> T getBean(String name, Class<T> requiredType) throws BeansException {
　　　　return doGetBean(name, requiredType, null, false);
　　}

　　@Override
　　public Object getBean(String name, Object... args) throws BeansException {
　　　　return doGetBean(name, null, args, false);
　　}

　　/**
　　* Return an instance, which may be shared or independent, of the specified bean.
　　* @param name the name of the bean to retrieve
　　* @param requiredType the required type of the bean to retrieve
　　* @param args arguments to use when creating a bean instance using explicit arguments
　　* (only applied when creating a new instance as opposed to retrieving an existing one)
　　* @return an instance of the bean
　　* @throws BeansException if the bean could not be created
　　*/
　　public <T> T getBean(String name, Class<T> requiredType, Object... args) throws BeansException {
　　　　return doGetBean(name, requiredType, args, false);
　　}

　　/**
　　* Return an instance, which may be shared or independent, of the specified bean.
　　* @param name the name of the bean to retrieve
　　* @param requiredType the required type of the bean to retrieve
　　* @param args arguments to use when creating a bean instance using explicit arguments
　　* (only applied when creating a new instance as opposed to retrieving an existing one)
　　* @param typeCheckOnly whether the instance is obtained for a type check,
　　* not for actual use
　　* @return an instance of the bean
　　* @throws BeansException if the bean could not be created
　　*/
　　@SuppressWarnings("unchecked")
　　protected <T> T doGetBean(final String name, final Class<T> requiredType, final Object[] args, boolean typeCheckOnly) throws BeansException {

　　调用transformedBeanName获取beanName：transformedBeanName调用canonicalName，参数为BeanFactoryUtils.transformedBeanName(name)，BeanFactoryUtils的transformedBeanName方法会去除beanName的工厂前缀；canonicalName方法将name当作别名，找到最原始的name；

　　final String beanName = transformedBeanName(name);

　　Object bean;

　　// Eagerly check singleton cache for manually registered singletons.

　　调用getSingleton(beanName)：获取beanFactory的singletonObjects中已经包含的单例，如果earlySingletonObjects未找到并且isSingletonCurrentlyInCreation，则去获取earlySingletonObjects属性中的单例，如果还未找到 并且allowEarlyReference，则去　　　　

　　singletonFactories属性中获取bean
　　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 + "'");
　　　　　　}
　　　　}
　　　　bean = getObjectForBeanInstance(sharedInstance, name, beanName, null);
　　}

　　else {
　　　　// Fail if we're already creating this bean instance:
　　　　// We're assumably within a circular reference.

　　　　//未找到singleton且参数args为null，如果isPrototypeCurrentlyInCreation，可能存在循环引用，抛BeanCurrentlyInCreationException
　　　　if (isPrototypeCurrentlyInCreation(beanName)) {
　　　　　　throw new BeanCurrentlyInCreationException(beanName);
　　　　}

　　// getParentBeanFactory不为null且包含当前beanName，调用originalBeanName方法获取工厂bean名称，这个方法调用transformedBeanName后为beanName加上工厂bean的前缀，然后调用parentBeanFactory的getBean方法
　　BeanFactory parentBeanFactory = getParentBeanFactory();
　　if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
　　　　// Not found -> check parent.
　　　　String nameToLookup = originalBeanName(name);
　　　　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typeCheckOnly，markBeanAsCreated：将beanName加入到beanFactory的alreadyCreated属性中，然后clearMergedBeanDefinition，将beanName从beanFactory的mergedBeanDefinitions属性中移除（正在真正的创建bean，让beanDefinition能够re-　　

　　merged，防止它的metadata在创建时发生改变。）

　　if (!typeCheckOnly) {
　　　　markBeanAsCreated(beanName);
　　}

　　try {

　　　　//而加载bean的第一步就是获取bean的RootBeanDefinition，获取RootBeanDefinition的过程就是子bean合并父bean配置信息的过程

　　　　  getMergedLocalBeanDefinition 从parent beanDefinition和子beanDefinition获取合并后的merged RootBeanDefinition
　　　　final RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);

　　　　//checkMergedBeanDefinition 如果beanDefinition为抽象的则抛出BeanIsAbstractException
　　　　checkMergedBeanDefinition(mbd, beanName, args);

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

　　　　//获取beanDefinition的dependsOn，然后registerDependentBean，getBean，确保当前bean依赖的bean都能初始化完成
　　　　String[] dependsOn = mbd.getDependsOn();
　　　　if (dependsOn != null) {
　　　　　　for (String dep : dependsOn) {
　　　　　　　　if (isDependent(beanName, dep)) {
　　　　　　　　　　throw new BeanCreationException(mbd.getResourceDescription(), beanName,
　　　　　　　　　　"Circular depends-on relationship between '" + beanName + "' and '" + dep + "'");
　　　　　　　　}
　　　　　　　　registerDependentBean(dep, beanName);
　　　　　　　　getBean(dep);
　　　　　 }
　　　　}

　　　　// Create bean instance.
　　　　if (mbd.isSingleton()) {

　　　　//从beanFactory的singletonObjects属性中获取单例缓存，如果为空：先调用beforeSingletonCreation，如果beanFactory的inCreationCheckExclusions属性中不包含当前beanName并且向singletonsCurrentlyInCreation属性中添加beanName失败，抛出

               BeanCurrentlyInCreationException；然后调用singletonFactory的getObject方法，getObject方法调用的是AbstractBeanFactory的createBean方法；然后调用afterSingletonCreation，如果beanFactory的inCreationCheckExclusions属性中不包含当前beanName并

              且从singletonsCurrentlyInCreation属性中移除beanName失败，抛出IllegalStateException；最后调用addSingleton，将beanName及新建的bean加入到beanFactory的singletonObjects，将beanName加入到registeredSingletons，从singletonFactories和

               earlySingletonObjects移除beanName。
　　　　　　sharedInstance = getSingleton(beanName, new ObjectFactory<Object>() {
　　　　　　　　@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 {
　　　　　　String scopeName = mbd.getScope();
　　　　　　final 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, new ObjectFactory<Object>() {
　　　　　　　　@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;
　　}
}

// Check if required type matches the type of the actual bean instance.
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;
}

@Override
public boolean containsBean(String name) {
String beanName = transformedBeanName(name);
if (containsSingleton(beanName) || containsBeanDefinition(beanName)) {
return (!BeanFactoryUtils.isFactoryDereference(name) || isFactoryBean(name));
}
// Not found -> check parent.
BeanFactory parentBeanFactory = getParentBeanFactory();
return (parentBeanFactory != null && parentBeanFactory.containsBean(originalBeanName(name)));
}

@Override
public boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
String beanName = transformedBeanName(name);

Object beanInstance = getSingleton(beanName, false);
if (beanInstance != null) {
if (beanInstance instanceof FactoryBean) {
return (BeanFactoryUtils.isFactoryDereference(name) || ((FactoryBean<?>) beanInstance).isSingleton());
}
else {
return !BeanFactoryUtils.isFactoryDereference(name);
}
}
else if (containsSingleton(beanName)) {
return true;
}

else {
// No singleton instance found -> check bean definition.
BeanFactory parentBeanFactory = getParentBeanFactory();
if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
// No bean definition found in this factory -> delegate to parent.
return parentBeanFactory.isSingleton(originalBeanName(name));
}

RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);

// In case of FactoryBean, return singleton status of created object if not a dereference.
if (mbd.isSingleton()) {
if (isFactoryBean(beanName, mbd)) {
if (BeanFactoryUtils.isFactoryDereference(name)) {
return true;
}
FactoryBean<?> factoryBean = (FactoryBean<?>) getBean(FACTORY_BEAN_PREFIX + beanName);
return factoryBean.isSingleton();
}
else {
return !BeanFactoryUtils.isFactoryDereference(name);
}
}
else {
return false;
}
}
}

@Override
public boolean isPrototype(String name) throws NoSuchBeanDefinitionException {
String beanName = transformedBeanName(name);

BeanFactory parentBeanFactory = getParentBeanFactory();
if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
// No bean definition found in this factory -> delegate to parent.
return parentBeanFactory.isPrototype(originalBeanName(name));
}

RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
if (mbd.isPrototype()) {
// In case of FactoryBean, return singleton status of created object if not a dereference.
return (!BeanFactoryUtils.isFactoryDereference(name) || isFactoryBean(beanName, mbd));
}
else {
// Singleton or scoped - not a prototype.
// However, FactoryBean may still produce a prototype object...
if (BeanFactoryUtils.isFactoryDereference(name)) {
return false;
}
if (isFactoryBean(beanName, mbd)) {
final FactoryBean<?> fb = (FactoryBean<?>) getBean(FACTORY_BEAN_PREFIX + beanName);
if (System.getSecurityManager() != null) {
return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
@Override
public Boolean run() {
return ((fb instanceof SmartFactoryBean && ((SmartFactoryBean<?>) fb).isPrototype()) ||
!fb.isSingleton());
}
}, getAccessControlContext());
}
else {
return ((fb instanceof SmartFactoryBean && ((SmartFactoryBean<?>) fb).isPrototype()) ||
!fb.isSingleton());
}
}
else {
return false;
}
}
}

@Override
public boolean isTypeMatch(String name, ResolvableType typeToMatch) throws NoSuchBeanDefinitionException {
String beanName = transformedBeanName(name);

// Check manually registered singletons.
Object beanInstance = getSingleton(beanName, false);
if (beanInstance != null) {
if (beanInstance instanceof FactoryBean) {
if (!BeanFactoryUtils.isFactoryDereference(name)) {
Class<?> type = getTypeForFactoryBean((FactoryBean<?>) beanInstance);
return (type != null && typeToMatch.isAssignableFrom(type));
}
else {
return typeToMatch.isInstance(beanInstance);
}
}
else {
return (!BeanFactoryUtils.isFactoryDereference(name) && typeToMatch.isInstance(beanInstance));
}
}
else if (containsSingleton(beanName) && !containsBeanDefinition(beanName)) {
// null instance registered
return false;
}

else {
// No singleton instance found -> check bean definition.
BeanFactory parentBeanFactory = getParentBeanFactory();
if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
// No bean definition found in this factory -> delegate to parent.
return parentBeanFactory.isTypeMatch(originalBeanName(name), typeToMatch);
}

// Retrieve corresponding bean definition.
RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);

Class<?> classToMatch = typeToMatch.getRawClass();
Class<?>[] typesToMatch = (FactoryBean.class == classToMatch ?
new Class<?>[] {classToMatch} : new Class<?>[] {FactoryBean.class, classToMatch});

// Check decorated bean definition, if any: We assume it'll be easier
// to determine the decorated bean's type than the proxy's type.
BeanDefinitionHolder dbd = mbd.getDecoratedDefinition();
if (dbd != null && !BeanFactoryUtils.isFactoryDereference(name)) {
RootBeanDefinition tbd = getMergedBeanDefinition(dbd.getBeanName(), dbd.getBeanDefinition(), mbd);
Class<?> targetClass = predictBeanType(dbd.getBeanName(), tbd, typesToMatch);
if (targetClass != null && !FactoryBean.class.isAssignableFrom(targetClass)) {
return typeToMatch.isAssignableFrom(targetClass);
}
}

Class<?> beanType = predictBeanType(beanName, mbd, typesToMatch);
if (beanType == null) {
return false;
}

// Check bean class whether we're dealing with a FactoryBean.
if (FactoryBean.class.isAssignableFrom(beanType)) {
if (!BeanFactoryUtils.isFactoryDereference(name)) {
// If it's a FactoryBean, we want to look at what it creates, not the factory class.
beanType = getTypeForFactoryBean(beanName, mbd);
if (beanType == null) {
return false;
}
}
}
else if (BeanFactoryUtils.isFactoryDereference(name)) {
// Special case: A SmartInstantiationAwareBeanPostProcessor returned a non-FactoryBean
// type but we nevertheless are being asked to dereference a FactoryBean...
// Let's check the original bean class and proceed with it if it is a FactoryBean.
beanType = predictBeanType(beanName, mbd, FactoryBean.class);
if (beanType == null || !FactoryBean.class.isAssignableFrom(beanType)) {
return false;
}
}

return typeToMatch.isAssignableFrom(beanType);
}
}

@Override
public boolean isTypeMatch(String name, Class<?> typeToMatch) throws NoSuchBeanDefinitionException {
return isTypeMatch(name, ResolvableType.forRawClass(typeToMatch));
}

@Override
public Class<?> getType(String name) throws NoSuchBeanDefinitionException {
String beanName = transformedBeanName(name);

// Check manually registered singletons.
Object beanInstance = getSingleton(beanName, false);
if (beanInstance != null) {
if (beanInstance instanceof FactoryBean && !BeanFactoryUtils.isFactoryDereference(name)) {
return getTypeForFactoryBean((FactoryBean<?>) beanInstance);
}
else {
return beanInstance.getClass();
}
}
else if (containsSingleton(beanName) && !containsBeanDefinition(beanName)) {
// null instance registered
return null;
}

else {
// No singleton instance found -> check bean definition.
BeanFactory parentBeanFactory = getParentBeanFactory();
if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
// No bean definition found in this factory -> delegate to parent.
return parentBeanFactory.getType(originalBeanName(name));
}

RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);

// Check decorated bean definition, if any: We assume it'll be easier
// to determine the decorated bean's type than the proxy's type.
BeanDefinitionHolder dbd = mbd.getDecoratedDefinition();
if (dbd != null && !BeanFactoryUtils.isFactoryDereference(name)) {
RootBeanDefinition tbd = getMergedBeanDefinition(dbd.getBeanName(), dbd.getBeanDefinition(), mbd);
Class<?> targetClass = predictBeanType(dbd.getBeanName(), tbd);
if (targetClass != null && !FactoryBean.class.isAssignableFrom(targetClass)) {
return targetClass;
}
}

Class<?> beanClass = predictBeanType(beanName, mbd);

// Check bean class whether we're dealing with a FactoryBean.
if (beanClass != null && FactoryBean.class.isAssignableFrom(beanClass)) {
if (!BeanFactoryUtils.isFactoryDereference(name)) {
// If it's a FactoryBean, we want to look at what it creates, not at the factory class.
return getTypeForFactoryBean(beanName, mbd);
}
else {
return beanClass;
}
}
else {
return (!BeanFactoryUtils.isFactoryDereference(name) ? beanClass : null);
}
}
}

@Override
public String[] getAliases(String name) {
String beanName = transformedBeanName(name);
List<String> aliases = new ArrayList<>();
boolean factoryPrefix = name.startsWith(FACTORY_BEAN_PREFIX);
String fullBeanName = beanName;
if (factoryPrefix) {
fullBeanName = FACTORY_BEAN_PREFIX + beanName;
}
if (!fullBeanName.equals(name)) {
aliases.add(fullBeanName);
}
String[] retrievedAliases = super.getAliases(beanName);
for (String retrievedAlias : retrievedAliases) {
String alias = (factoryPrefix ? FACTORY_BEAN_PREFIX : "") + retrievedAlias;
if (!alias.equals(name)) {
aliases.add(alias);
}
}
if (!containsSingleton(beanName) && !containsBeanDefinition(beanName)) {
BeanFactory parentBeanFactory = getParentBeanFactory();
if (parentBeanFactory != null) {
aliases.addAll(Arrays.asList(parentBeanFactory.getAliases(fullBeanName)));
}
}
return StringUtils.toStringArray(aliases);
}

//---------------------------------------------------------------------
// Implementation of HierarchicalBeanFactory interface
//---------------------------------------------------------------------

@Override
public BeanFactory getParentBeanFactory() {
return this.parentBeanFactory;
}

@Override
public boolean containsLocalBean(String name) {
String beanName = transformedBeanName(name);
return ((containsSingleton(beanName) || containsBeanDefinition(beanName)) &&
(!BeanFactoryUtils.isFactoryDereference(name) || isFactoryBean(beanName)));
}

//---------------------------------------------------------------------
// Implementation of ConfigurableBeanFactory interface
//---------------------------------------------------------------------

@Override
public void setParentBeanFactory(BeanFactory parentBeanFactory) {
if (this.parentBeanFactory != null && this.parentBeanFactory != parentBeanFactory) {
throw new IllegalStateException("Already associated with parent BeanFactory: " + this.parentBeanFactory);
}
this.parentBeanFactory = parentBeanFactory;
}

@Override
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = (beanClassLoader != null ? beanClassLoader : ClassUtils.getDefaultClassLoader());
}

@Override
public ClassLoader getBeanClassLoader() {
return this.beanClassLoader;
}

@Override
public void setTempClassLoader(ClassLoader tempClassLoader) {
this.tempClassLoader = tempClassLoader;
}

@Override
public ClassLoader getTempClassLoader() {
return this.tempClassLoader;
}

@Override
public void setCacheBeanMetadata(boolean cacheBeanMetadata) {
this.cacheBeanMetadata = cacheBeanMetadata;
}

@Override
public boolean isCacheBeanMetadata() {
return this.cacheBeanMetadata;
}

@Override
public void setBeanExpressionResolver(BeanExpressionResolver resolver) {
this.beanExpressionResolver = resolver;
}

@Override
public BeanExpressionResolver getBeanExpressionResolver() {
return this.beanExpressionResolver;
}

@Override
public void setConversionService(ConversionService conversionService) {
this.conversionService = conversionService;
}

@Override
public ConversionService getConversionService() {
return this.conversionService;
}

@Override
public void addPropertyEditorRegistrar(PropertyEditorRegistrar registrar) {
Assert.notNull(registrar, "PropertyEditorRegistrar must not be null");
this.propertyEditorRegistrars.add(registrar);
}

/**
* Return the set of PropertyEditorRegistrars.
*/
public Set<PropertyEditorRegistrar> getPropertyEditorRegistrars() {
return this.propertyEditorRegistrars;
}

@Override
public void registerCustomEditor(Class<?> requiredType, Class<? extends PropertyEditor> propertyEditorClass) {
Assert.notNull(requiredType, "Required type must not be null");
Assert.isAssignable(PropertyEditor.class, propertyEditorClass);
this.customEditors.put(requiredType, propertyEditorClass);
}

@Override
public void copyRegisteredEditorsTo(PropertyEditorRegistry registry) {
registerCustomEditors(registry);
}

/**
* Return the map of custom editors, with Classes as keys and PropertyEditor classes as values.
*/
public Map<Class<?>, Class<? extends PropertyEditor>> getCustomEditors() {
return this.customEditors;
}

@Override
public void setTypeConverter(TypeConverter typeConverter) {
this.typeConverter = typeConverter;
}

/**
* Return the custom TypeConverter to use, if any.
* @return the custom TypeConverter, or {@code null} if none specified
*/
protected TypeConverter getCustomTypeConverter() {
return this.typeConverter;
}

@Override
public TypeConverter getTypeConverter() {
TypeConverter customConverter = getCustomTypeConverter();
if (customConverter != null) {
return customConverter;
}
else {
// Build default TypeConverter, registering custom editors.
SimpleTypeConverter typeConverter = new SimpleTypeConverter();
typeConverter.setConversionService(getConversionService());
registerCustomEditors(typeConverter);
return typeConverter;
}
}

@Override
public void addEmbeddedValueResolver(StringValueResolver valueResolver) {
Assert.notNull(valueResolver, "StringValueResolver must not be null");
this.embeddedValueResolvers.add(valueResolver);
}

@Override
public boolean hasEmbeddedValueResolver() {
return !this.embeddedValueResolvers.isEmpty();
}

@Override
public String resolveEmbeddedValue(String value) {
if (value == null) {
return null;
}
String result = value;
for (StringValueResolver resolver : this.embeddedValueResolvers) {
result = resolver.resolveStringValue(result);
if (result == null) {
return null;
}
}
return result;
}

@Override
public void addBeanPostProcessor(BeanPostProcessor beanPostProcessor) {
Assert.notNull(beanPostProcessor, "BeanPostProcessor must not be null");
this.beanPostProcessors.remove(beanPostProcessor);
this.beanPostProcessors.add(beanPostProcessor);
if (beanPostProcessor instanceof InstantiationAwareBeanPostProcessor) {
this.hasInstantiationAwareBeanPostProcessors = true;
}
if (beanPostProcessor instanceof DestructionAwareBeanPostProcessor) {
this.hasDestructionAwareBeanPostProcessors = true;
}
}

@Override
public int getBeanPostProcessorCount() {
return this.beanPostProcessors.size();
}

/**
* Return the list of BeanPostProcessors that will get applied
* to beans created with this factory.
*/
public List<BeanPostProcessor> getBeanPostProcessors() {
return this.beanPostProcessors;
}

/**
* Return whether this factory holds a InstantiationAwareBeanPostProcessor
* that will get applied to singleton beans on shutdown.
* @see #addBeanPostProcessor
* @see org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor
*/
protected boolean hasInstantiationAwareBeanPostProcessors() {
return this.hasInstantiationAwareBeanPostProcessors;
}

/**
* Return whether this factory holds a DestructionAwareBeanPostProcessor
* that will get applied to singleton beans on shutdown.
* @see #addBeanPostProcessor
* @see org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor
*/
protected boolean hasDestructionAwareBeanPostProcessors() {
return this.hasDestructionAwareBeanPostProcessors;
}

@Override
public void registerScope(String scopeName, Scope scope) {
Assert.notNull(scopeName, "Scope identifier must not be null");
Assert.notNull(scope, "Scope must not be null");
if (SCOPE_SINGLETON.equals(scopeName) || SCOPE_PROTOTYPE.equals(scopeName)) {
throw new IllegalArgumentException("Cannot replace existing scopes 'singleton' and 'prototype'");
}
Scope previous = this.scopes.put(scopeName, scope);
if (previous != null && previous != scope) {
if (logger.isInfoEnabled()) {
logger.info("Replacing scope '" + scopeName + "' from [" + previous + "] to [" + scope + "]");
}
}
else {
if (logger.isDebugEnabled()) {
logger.debug("Registering scope '" + scopeName + "' with implementation [" + scope + "]");
}
}
}

@Override
public String[] getRegisteredScopeNames() {
return StringUtils.toStringArray(this.scopes.keySet());
}

@Override
public Scope getRegisteredScope(String scopeName) {
Assert.notNull(scopeName, "Scope identifier must not be null");
return this.scopes.get(scopeName);
}

/**
* Set the security context provider for this bean factory. If a security manager
* is set, interaction with the user code will be executed using the privileged
* of the provided security context.
*/
public void setSecurityContextProvider(SecurityContextProvider securityProvider) {
this.securityContextProvider = securityProvider;
}

/**
* Delegate the creation of the access control context to the
* {@link #setSecurityContextProvider SecurityContextProvider}.
*/
@Override
public AccessControlContext getAccessControlContext() {
return (this.securityContextProvider != null ?
this.securityContextProvider.getAccessControlContext() :
AccessController.getContext());
}

@Override
public void copyConfigurationFrom(ConfigurableBeanFactory otherFactory) {
Assert.notNull(otherFactory, "BeanFactory must not be null");
setBeanClassLoader(otherFactory.getBeanClassLoader());
setCacheBeanMetadata(otherFactory.isCacheBeanMetadata());
setBeanExpressionResolver(otherFactory.getBeanExpressionResolver());
if (otherFactory instanceof AbstractBeanFactory) {
AbstractBeanFactory otherAbstractFactory = (AbstractBeanFactory) otherFactory;
this.customEditors.putAll(otherAbstractFactory.customEditors);
this.propertyEditorRegistrars.addAll(otherAbstractFactory.propertyEditorRegistrars);
this.beanPostProcessors.addAll(otherAbstractFactory.beanPostProcessors);
this.hasInstantiationAwareBeanPostProcessors = this.hasInstantiationAwareBeanPostProcessors ||
otherAbstractFactory.hasInstantiationAwareBeanPostProcessors;
this.hasDestructionAwareBeanPostProcessors = this.hasDestructionAwareBeanPostProcessors ||
otherAbstractFactory.hasDestructionAwareBeanPostProcessors;
this.scopes.putAll(otherAbstractFactory.scopes);
this.securityContextProvider = otherAbstractFactory.securityContextProvider;
}
else {
setTypeConverter(otherFactory.getTypeConverter());
}
}

/**
* Return a 'merged' BeanDefinition for the given bean name,
* merging a child bean definition with its parent if necessary.
* <p>This {@code getMergedBeanDefinition} considers bean definition
* in ancestors as well.
* @param name the name of the bean to retrieve the merged definition for
* (may be an alias)
* @return a (potentially merged) RootBeanDefinition for the given bean
* @throws NoSuchBeanDefinitionException if there is no bean with the given name
* @throws BeanDefinitionStoreException in case of an invalid bean definition
*/
@Override
public BeanDefinition getMergedBeanDefinition(String name) throws BeansException {
String beanName = transformedBeanName(name);

// Efficiently check whether bean definition exists in this factory.
if (!containsBeanDefinition(beanName) && getParentBeanFactory() instanceof ConfigurableBeanFactory) {
return ((ConfigurableBeanFactory) getParentBeanFactory()).getMergedBeanDefinition(beanName);
}
// Resolve merged bean definition locally.
return getMergedLocalBeanDefinition(beanName);
}

@Override
public boolean isFactoryBean(String name) throws NoSuchBeanDefinitionException {
String beanName = transformedBeanName(name);

Object beanInstance = getSingleton(beanName, false);
if (beanInstance != null) {
return (beanInstance instanceof FactoryBean);
}
else if (containsSingleton(beanName)) {
// null instance registered
return false;
}

// No singleton instance found -> check bean definition.
if (!containsBeanDefinition(beanName) && getParentBeanFactory() instanceof ConfigurableBeanFactory) {
// No bean definition found in this factory -> delegate to parent.
return ((ConfigurableBeanFactory) getParentBeanFactory()).isFactoryBean(name);
}

return isFactoryBean(beanName, getMergedLocalBeanDefinition(beanName));
}

@Override
public boolean isActuallyInCreation(String beanName) {
return (isSingletonCurrentlyInCreation(beanName) || isPrototypeCurrentlyInCreation(beanName));
}

/**
* Return whether the specified prototype bean is currently in creation
* (within the current thread).
* @param beanName the name of the bean
*/
protected boolean isPrototypeCurrentlyInCreation(String beanName) {
Object curVal = this.prototypesCurrentlyInCreation.get();
return (curVal != null &&
(curVal.equals(beanName) || (curVal instanceof Set && ((Set<?>) curVal).contains(beanName))));
}

/**
* Callback before prototype creation.
* <p>The default implementation register the prototype as currently in creation.
* @param beanName the name of the prototype about to be created
* @see #isPrototypeCurrentlyInCreation
*/
@SuppressWarnings("unchecked")
protected void beforePrototypeCreation(String beanName) {
Object curVal = this.prototypesCurrentlyInCreation.get();
if (curVal == null) {
this.prototypesCurrentlyInCreation.set(beanName);
}
else if (curVal instanceof String) {
Set<String> beanNameSet = new HashSet<>(2);
beanNameSet.add((String) curVal);
beanNameSet.add(beanName);
this.prototypesCurrentlyInCreation.set(beanNameSet);
}
else {
Set<String> beanNameSet = (Set<String>) curVal;
beanNameSet.add(beanName);
}
}

/**
* Callback after prototype creation.
* <p>The default implementation marks the prototype as not in creation anymore.
* @param beanName the name of the prototype that has been created
* @see #isPrototypeCurrentlyInCreation
*/
@SuppressWarnings("unchecked")
protected void afterPrototypeCreation(String beanName) {
Object curVal = this.prototypesCurrentlyInCreation.get();
if (curVal instanceof String) {
this.prototypesCurrentlyInCreation.remove();
}
else if (curVal instanceof Set) {
Set<String> beanNameSet = (Set<String>) curVal;
beanNameSet.remove(beanName);
if (beanNameSet.isEmpty()) {
this.prototypesCurrentlyInCreation.remove();
}
}
}

@Override
public void destroyBean(String beanName, Object beanInstance) {
destroyBean(beanName, beanInstance, getMergedLocalBeanDefinition(beanName));
}

/**
* Destroy the given bean instance (usually a prototype instance
* obtained from this factory) according to the given bean definition.
* @param beanName the name of the bean definition
* @param bean the bean instance to destroy
* @param mbd the merged bean definition
*/
protected void destroyBean(String beanName, Object bean, RootBeanDefinition mbd) {
new DisposableBeanAdapter(bean, beanName, mbd, getBeanPostProcessors(), getAccessControlContext()).destroy();
}

@Override
public void destroyScopedBean(String beanName) {
RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
if (mbd.isSingleton() || mbd.isPrototype()) {
throw new IllegalArgumentException(
"Bean name '" + beanName + "' does not correspond to an object in a mutable scope");
}
String scopeName = mbd.getScope();
Scope scope = this.scopes.get(scopeName);
if (scope == null) {
throw new IllegalStateException("No Scope SPI registered for scope name '" + scopeName + "'");
}
Object bean = scope.remove(beanName);
if (bean != null) {
destroyBean(beanName, bean, mbd);
}
}

//---------------------------------------------------------------------
// Implementation methods
//---------------------------------------------------------------------

/**
* Return the bean name, stripping out the factory dereference prefix if necessary,
* and resolving aliases to canonical names.
* @param name the user-specified name
* @return the transformed bean name
*/
protected String transformedBeanName(String name) {
return canonicalName(BeanFactoryUtils.transformedBeanName(name));
}

/**
* Determine the original bean name, resolving locally defined aliases to canonical names.
* @param name the user-specified name
* @return the original bean name
*/
protected String originalBeanName(String name) {
String beanName = transformedBeanName(name);
if (name.startsWith(FACTORY_BEAN_PREFIX)) {
beanName = FACTORY_BEAN_PREFIX + beanName;
}
return beanName;
}

/**
* Initialize the given BeanWrapper with the custom editors registered
* with this factory. To be called for BeanWrappers that will create
* and populate bean instances.
* <p>The default implementation delegates to {@link #registerCustomEditors}.
* Can be overridden in subclasses.
* @param bw the BeanWrapper to initialize
*/
protected void initBeanWrapper(BeanWrapper bw) {
bw.setConversionService(getConversionService());
registerCustomEditors(bw);
}

/**
* Initialize the given PropertyEditorRegistry with the custom editors
* that have been registered with this BeanFactory.
* <p>To be called for BeanWrappers that will create and populate bean
* instances, and for SimpleTypeConverter used for constructor argument
* and factory method type conversion.
* @param registry the PropertyEditorRegistry to initialize
*/
protected void registerCustomEditors(PropertyEditorRegistry registry) {
PropertyEditorRegistrySupport registrySupport =
(registry instanceof PropertyEditorRegistrySupport ? (PropertyEditorRegistrySupport) registry : null);
if (registrySupport != null) {
registrySupport.useConfigValueEditors();
}
if (!this.propertyEditorRegistrars.isEmpty()) {
for (PropertyEditorRegistrar registrar : this.propertyEditorRegistrars) {
try {
registrar.registerCustomEditors(registry);
}
catch (BeanCreationException ex) {
Throwable rootCause = ex.getMostSpecificCause();
if (rootCause instanceof BeanCurrentlyInCreationException) {
BeanCreationException bce = (BeanCreationException) rootCause;
if (isCurrentlyInCreation(bce.getBeanName())) {
if (logger.isDebugEnabled()) {
logger.debug("PropertyEditorRegistrar [" + registrar.getClass().getName() +
"] failed because it tried to obtain currently created bean '" +
ex.getBeanName() + "': " + ex.getMessage());
}
onSuppressedException(ex);
continue;
}
}
throw ex;
}
}
}
if (!this.customEditors.isEmpty()) {
for (Map.Entry<Class<?>, Class<? extends PropertyEditor>> entry : this.customEditors.entrySet()) {
Class<?> requiredType = entry.getKey();
Class<? extends PropertyEditor> editorClass = entry.getValue();
registry.registerCustomEditor(requiredType, BeanUtils.instantiateClass(editorClass));
}
}
}

/**
* Return a merged RootBeanDefinition, traversing the parent bean definition
* if the specified bean corresponds to a child bean definition.
* @param beanName the name of the bean to retrieve the merged definition for
* @return a (potentially merged) RootBeanDefinition for the given bean
* @throws NoSuchBeanDefinitionException if there is no bean with the given name
* @throws BeanDefinitionStoreException in case of an invalid bean definition
*/
protected RootBeanDefinition getMergedLocalBeanDefinition(String beanName) throws BeansException {
// Quick check on the concurrent map first, with minimal locking.
RootBeanDefinition mbd = this.mergedBeanDefinitions.get(beanName);
if (mbd != null) {
return mbd;
}
return getMergedBeanDefinition(beanName, getBeanDefinition(beanName));
}

/**
* Return a RootBeanDefinition for the given top-level bean, by merging with
* the parent if the given bean's definition is a child bean definition.
* @param beanName the name of the bean definition
* @param bd the original bean definition (Root/ChildBeanDefinition)
* @return a (potentially merged) RootBeanDefinition for the given bean
* @throws BeanDefinitionStoreException in case of an invalid bean definition
*/
protected RootBeanDefinition getMergedBeanDefinition(String beanName, BeanDefinition bd)
throws BeanDefinitionStoreException {

return getMergedBeanDefinition(beanName, bd, null);
}

/**
* Return a RootBeanDefinition for the given bean, by merging with the
* parent if the given bean's definition is a child bean definition.
* @param beanName the name of the bean definition
* @param bd the original bean definition (Root/ChildBeanDefinition)
* @param containingBd the containing bean definition in case of inner bean,
* or {@code null} in case of a top-level bean
* @return a (potentially merged) RootBeanDefinition for the given bean
* @throws BeanDefinitionStoreException in case of an invalid bean definition
*/
protected RootBeanDefinition getMergedBeanDefinition(
String beanName, BeanDefinition bd, BeanDefinition containingBd)
throws BeanDefinitionStoreException {

synchronized (this.mergedBeanDefinitions) {
RootBeanDefinition mbd = null;

// Check with full lock now in order to enforce the same merged instance.
if (containingBd == null) {
mbd = this.mergedBeanDefinitions.get(beanName);
}

if (mbd == null) {
if (bd.getParentName() == null) {
// Use copy of given root bean definition.
if (bd instanceof RootBeanDefinition) {
mbd = ((RootBeanDefinition) bd).cloneBeanDefinition();
}
else {
mbd = new RootBeanDefinition(bd);
}
}
else {
// Child bean definition: needs to be merged with parent.
BeanDefinition pbd;
try {
String parentBeanName = transformedBeanName(bd.getParentName());
if (!beanName.equals(parentBeanName)) {
pbd = getMergedBeanDefinition(parentBeanName);
}
else {
BeanFactory parent = getParentBeanFactory();
if (parent instanceof ConfigurableBeanFactory) {
pbd = ((ConfigurableBeanFactory) parent).getMergedBeanDefinition(parentBeanName);
}
else {
throw new NoSuchBeanDefinitionException(parentBeanName,
"Parent name '" + parentBeanName + "' is equal to bean name '" + beanName +
"': cannot be resolved without an AbstractBeanFactory parent");
}
}
}
catch (NoSuchBeanDefinitionException ex) {
throw new BeanDefinitionStoreException(bd.getResourceDescription(), beanName,
"Could not resolve parent bean definition '" + bd.getParentName() + "'", ex);
}
// Deep copy with overridden values.
mbd = new RootBeanDefinition(pbd);
mbd.overrideFrom(bd);
}

// Set default singleton scope, if not configured before.
if (!StringUtils.hasLength(mbd.getScope())) {
mbd.setScope(RootBeanDefinition.SCOPE_SINGLETON);
}

// A bean contained in a non-singleton bean cannot be a singleton itself.
// Let's correct this on the fly here, since this might be the result of
// parent-child merging for the outer bean, in which case the original inner bean
// definition will not have inherited the merged outer bean's singleton status.
if (containingBd != null && !containingBd.isSingleton() && mbd.isSingleton()) {
mbd.setScope(containingBd.getScope());
}

// Only cache the merged bean definition if we're already about to create an
// instance of the bean, or at least have already created an instance before.
if (containingBd == null && isCacheBeanMetadata()) {
this.mergedBeanDefinitions.put(beanName, mbd);
}
}

return mbd;
}
}

/**
* Check the given merged bean definition,
* potentially throwing validation exceptions.
* @param mbd the merged bean definition to check
* @param beanName the name of the bean
* @param args the arguments for bean creation, if any
* @throws BeanDefinitionStoreException in case of validation failure
*/
protected void checkMergedBeanDefinition(RootBeanDefinition mbd, String beanName, Object[] args)
throws BeanDefinitionStoreException {

if (mbd.isAbstract()) {
throw new BeanIsAbstractException(beanName);
}
}

/**
* Remove the merged bean definition for the specified bean,
* recreating it on next access.
* @param beanName the bean name to clear the merged definition for
*/
protected void clearMergedBeanDefinition(String beanName) {
this.mergedBeanDefinitions.remove(beanName);
}

/**
* Clear the merged bean definition cache, removing entries for beans
* which are not considered eligible for full metadata caching yet.
* <p>Typically triggered after changes to the original bean definitions,
* e.g. after applying a {@code BeanFactoryPostProcessor}. Note that metadata
* for beans which have already been created at this point will be kept around.
* @since 4.2
*/
public void clearMetadataCache() {
Iterator<String> mergedBeans = this.mergedBeanDefinitions.keySet().iterator();
while (mergedBeans.hasNext()) {
if (!isBeanEligibleForMetadataCaching(mergedBeans.next())) {
mergedBeans.remove();
}
}
}

/**
* Resolve the bean class for the specified bean definition,
* resolving a bean class name into a Class reference (if necessary)
* and storing the resolved Class in the bean definition for further use.
* @param mbd the merged bean definition to determine the class for
* @param beanName the name of the bean (for error handling purposes)
* @param typesToMatch the types to match in case of internal type matching purposes
* (also signals that the returned {@code Class} will never be exposed to application code)
* @return the resolved bean class (or {@code null} if none)
* @throws CannotLoadBeanClassException if we failed to load the class
*/
protected Class<?> resolveBeanClass(final RootBeanDefinition mbd, String beanName, final Class<?>... typesToMatch)
throws CannotLoadBeanClassException {
try {
if (mbd.hasBeanClass()) {
return mbd.getBeanClass();
}
if (System.getSecurityManager() != null) {
return AccessController.doPrivileged(new PrivilegedExceptionAction<Class<?>>() {
@Override
public Class<?> run() throws Exception {
return doResolveBeanClass(mbd, typesToMatch);
}
}, getAccessControlContext());
}
else {
return doResolveBeanClass(mbd, typesToMatch);
}
}
catch (PrivilegedActionException pae) {
ClassNotFoundException ex = (ClassNotFoundException) pae.getException();
throw new CannotLoadBeanClassException(mbd.getResourceDescription(), beanName, mbd.getBeanClassName(), ex);
}
catch (ClassNotFoundException ex) {
throw new CannotLoadBeanClassException(mbd.getResourceDescription(), beanName, mbd.getBeanClassName(), ex);
}
catch (LinkageError ex) {
throw new CannotLoadBeanClassException(mbd.getResourceDescription(), beanName, mbd.getBeanClassName(), ex);
}
}

private Class<?> doResolveBeanClass(RootBeanDefinition mbd, Class<?>... typesToMatch)
throws ClassNotFoundException {

ClassLoader beanClassLoader = getBeanClassLoader();
ClassLoader classLoaderToUse = beanClassLoader;
if (!ObjectUtils.isEmpty(typesToMatch)) {
// When just doing type checks (i.e. not creating an actual instance yet),
// use the specified temporary class loader (e.g. in a weaving scenario).
ClassLoader tempClassLoader = getTempClassLoader();
if (tempClassLoader != null) {
classLoaderToUse = tempClassLoader;
if (tempClassLoader instanceof DecoratingClassLoader) {
DecoratingClassLoader dcl = (DecoratingClassLoader) tempClassLoader;
for (Class<?> typeToMatch : typesToMatch) {
dcl.excludeClass(typeToMatch.getName());
}
}
}
}
String className = mbd.getBeanClassName();
if (className != null) {
Object evaluated = evaluateBeanDefinitionString(className, mbd);
if (!className.equals(evaluated)) {
// A dynamically resolved expression, supported as of 4.2...
if (evaluated instanceof Class) {
return (Class<?>) evaluated;
}
else if (evaluated instanceof String) {
return ClassUtils.forName((String) evaluated, classLoaderToUse);
}
else {
throw new IllegalStateException("Invalid class name expression result: " + evaluated);
}
}
// When resolving against a temporary class loader, exit early in order
// to avoid storing the resolved Class in the bean definition.
if (classLoaderToUse != beanClassLoader) {
return ClassUtils.forName(className, classLoaderToUse);
}
}
return mbd.resolveBeanClass(beanClassLoader);
}

/**
* Evaluate the given String as contained in a bean definition,
* potentially resolving it as an expression.
* @param value the value to check
* @param beanDefinition the bean definition that the value comes from
* @return the resolved value
* @see #setBeanExpressionResolver
*/
protected Object evaluateBeanDefinitionString(String value, BeanDefinition beanDefinition) {
if (this.beanExpressionResolver == null) {
return value;
}
Scope scope = (beanDefinition != null ? getRegisteredScope(beanDefinition.getScope()) : null);
return this.beanExpressionResolver.evaluate(value, new BeanExpressionContext(this, scope));
}

/**
* Predict the eventual bean type (of the processed bean instance) for the
* specified bean. Called by {@link #getType} and {@link #isTypeMatch}.
* Does not need to handle FactoryBeans specifically, since it is only
* supposed to operate on the raw bean type.
* <p>This implementation is simplistic in that it is not able to
* handle factory methods and InstantiationAwareBeanPostProcessors.
* It only predicts the bean type correctly for a standard bean.
* To be overridden in subclasses, applying more sophisticated type detection.
* @param beanName the name of the bean
* @param mbd the merged bean definition to determine the type for
* @param typesToMatch the types to match in case of internal type matching purposes
* (also signals that the returned {@code Class} will never be exposed to application code)
* @return the type of the bean, or {@code null} if not predictable
*/
protected Class<?> predictBeanType(String beanName, RootBeanDefinition mbd, Class<?>... typesToMatch) {
if (mbd.getFactoryMethodName() != null) {
return null;
}
return resolveBeanClass(mbd, beanName, typesToMatch);
}

/**
* Check whether the given bean is defined as a {@link FactoryBean}.
* @param beanName the name of the bean
* @param mbd the corresponding bean definition
*/
protected boolean isFactoryBean(String beanName, RootBeanDefinition mbd) {
Class<?> beanType = predictBeanType(beanName, mbd, FactoryBean.class);
return (beanType != null && FactoryBean.class.isAssignableFrom(beanType));
}

/**
* Determine the bean type for the given FactoryBean definition, as far as possible.
* Only called if there is no singleton instance registered for the target bean already.
* <p>The default implementation creates the FactoryBean via {@code getBean}
* to call its {@code getObjectType} method. Subclasses are encouraged to optimize
* this, typically by just instantiating the FactoryBean but not populating it yet,
* trying whether its {@code getObjectType} method already returns a type.
* If no type found, a full FactoryBean creation as performed by this implementation
* should be used as fallback.
* @param beanName the name of the bean
* @param mbd the merged bean definition for the bean
* @return the type for the bean if determinable, or {@code null} else
* @see org.springframework.beans.factory.FactoryBean#getObjectType()
* @see #getBean(String)
*/
protected Class<?> getTypeForFactoryBean(String beanName, RootBeanDefinition mbd) {
if (!mbd.isSingleton()) {
return null;
}
try {
FactoryBean<?> factoryBean = doGetBean(FACTORY_BEAN_PREFIX + beanName, FactoryBean.class, null, true);
return getTypeForFactoryBean(factoryBean);
}
catch (BeanCreationException ex) {
if (ex instanceof BeanCurrentlyInCreationException) {
if (logger.isDebugEnabled()) {
logger.debug("Bean currently in creation on FactoryBean type check: " + ex);
}
}
else if (mbd.isLazyInit()) {
if (logger.isDebugEnabled()) {
logger.debug("Bean creation exception on lazy FactoryBean type check: " + ex);
}
}
else {
if (logger.isWarnEnabled()) {
logger.warn("Bean creation exception on non-lazy FactoryBean type check: " + ex);
}
}
onSuppressedException(ex);
return null;
}
}

/**
* Mark the specified bean as already created (or about to be created).
* <p>This allows the bean factory to optimize its caching for repeated
* creation of the specified bean.
* @param beanName the name of the bean
*/
protected void markBeanAsCreated(String beanName) {
if (!this.alreadyCreated.contains(beanName)) {
synchronized (this.mergedBeanDefinitions) {
if (!this.alreadyCreated.contains(beanName)) {
// Let the bean definition get re-merged now that we're actually creating
// the bean... just in case some of its metadata changed in the meantime.
clearMergedBeanDefinition(beanName);
this.alreadyCreated.add(beanName);
}
}
}
}

/**
* Perform appropriate cleanup of cached metadata after bean creation failed.
* @param beanName the name of the bean
*/
protected void cleanupAfterBeanCreationFailure(String beanName) {
synchronized (this.mergedBeanDefinitions) {
this.alreadyCreated.remove(beanName);
}
}

/**
* Determine whether the specified bean is eligible for having
* its bean definition metadata cached.
* @param beanName the name of the bean
* @return {@code true} if the bean's metadata may be cached
* at this point already
*/
protected boolean isBeanEligibleForMetadataCaching(String beanName) {
return this.alreadyCreated.contains(beanName);
}

/**
* Remove the singleton instance (if any) for the given bean name,
* but only if it hasn't been used for other purposes than type checking.
* @param beanName the name of the bean
* @return {@code true} if actually removed, {@code false} otherwise
*/
protected boolean removeSingletonIfCreatedForTypeCheckOnly(String beanName) {
if (!this.alreadyCreated.contains(beanName)) {
removeSingleton(beanName);
return true;
}
else {
return false;
}
}

/**
* Check whether this factory's bean creation phase already started,
* i.e. whether any bean has been marked as created in the meantime.
* @since 4.2.2
* @see #markBeanAsCreated
*/
protected boolean hasBeanCreationStarted() {
return !this.alreadyCreated.isEmpty();
}

/**
* Get the object for the given bean instance, either the bean
* instance itself or its created object in case of a FactoryBean.
* @param beanInstance the shared bean instance
* @param name name that may include factory dereference prefix
* @param beanName the canonical bean name
* @param mbd the merged bean definition
* @return the object to expose for the bean
*/
protected Object getObjectForBeanInstance(
Object beanInstance, String name, String beanName, RootBeanDefinition mbd) {

// Don't let calling code try to dereference the factory if the bean isn't a factory.
if (BeanFactoryUtils.isFactoryDereference(name) && !(beanInstance instanceof FactoryBean)) {
throw new BeanIsNotAFactoryException(transformedBeanName(name), beanInstance.getClass());
}

// Now we have the bean instance, which may be a normal bean or a FactoryBean.
// If it's a FactoryBean, we use it to create a bean instance, unless the
// caller actually wants a reference to the factory.
if (!(beanInstance instanceof FactoryBean) || BeanFactoryUtils.isFactoryDereference(name)) {
return beanInstance;
}

Object object = null;
if (mbd == null) {
object = getCachedObjectForFactoryBean(beanName);
}
if (object == null) {
// Return bean instance from factory.
FactoryBean<?> factory = (FactoryBean<?>) beanInstance;
// Caches object obtained from FactoryBean if it is a singleton.
if (mbd == null && containsBeanDefinition(beanName)) {
mbd = getMergedLocalBeanDefinition(beanName);
}
boolean synthetic = (mbd != null && mbd.isSynthetic());
object = getObjectFromFactoryBean(factory, beanName, !synthetic);
}
return object;
}

/**
* Determine whether the given bean name is already in use within this factory,
* i.e. whether there is a local bean or alias registered under this name or
* an inner bean created with this name.
* @param beanName the name to check
*/
public boolean isBeanNameInUse(String beanName) {
return isAlias(beanName) || containsLocalBean(beanName) || hasDependentBean(beanName);
}

/**
* Determine whether the given bean requires destruction on shutdown.
* <p>The default implementation checks the DisposableBean interface as well as
* a specified destroy method and registered DestructionAwareBeanPostProcessors.
* @param bean the bean instance to check
* @param mbd the corresponding bean definition
* @see org.springframework.beans.factory.DisposableBean
* @see AbstractBeanDefinition#getDestroyMethodName()
* @see org.springframework.beans.factory.config.DestructionAwareBeanPostProcessor
*/
protected boolean requiresDestruction(Object bean, RootBeanDefinition mbd) {
return (bean != null &&
(DisposableBeanAdapter.hasDestroyMethod(bean, mbd) || (hasDestructionAwareBeanPostProcessors() &&
DisposableBeanAdapter.hasApplicableProcessors(bean, getBeanPostProcessors()))));
}

/**
* Add the given bean to the list of disposable beans in this factory,
* registering its DisposableBean interface and/or the given destroy method
* to be called on factory shutdown (if applicable). Only applies to singletons.
* @param beanName the name of the bean
* @param bean the bean instance
* @param mbd the bean definition for the bean
* @see RootBeanDefinition#isSingleton
* @see RootBeanDefinition#getDependsOn
* @see #registerDisposableBean
* @see #registerDependentBean
*/
protected void registerDisposableBeanIfNecessary(String beanName, Object bean, RootBeanDefinition mbd) {
AccessControlContext acc = (System.getSecurityManager() != null ? getAccessControlContext() : null);
if (!mbd.isPrototype() && requiresDestruction(bean, mbd)) {
if (mbd.isSingleton()) {
// Register a DisposableBean implementation that performs all destruction
// work for the given bean: DestructionAwareBeanPostProcessors,
// DisposableBean interface, custom destroy method.
registerDisposableBean(beanName,
new DisposableBeanAdapter(bean, beanName, mbd, getBeanPostProcessors(), acc));
}
else {
// A bean with a custom scope...
Scope scope = this.scopes.get(mbd.getScope());
if (scope == null) {
throw new IllegalStateException("No Scope registered for scope name '" + mbd.getScope() + "'");
}
scope.registerDestructionCallback(beanName,
new DisposableBeanAdapter(bean, beanName, mbd, getBeanPostProcessors(), acc));
}
}
}

//---------------------------------------------------------------------
// Abstract methods to be implemented by subclasses
//---------------------------------------------------------------------

/**
* Check if this bean factory contains a bean definition with the given name.
* Does not consider any hierarchy this factory may participate in.
* Invoked by {@code containsBean} when no cached singleton instance is found.
* <p>Depending on the nature of the concrete bean factory implementation,
* this operation might be expensive (for example, because of directory lookups
* in external registries). However, for listable bean factories, this usually
* just amounts to a local hash lookup: The operation is therefore part of the
* public interface there. The same implementation can serve for both this
* template method and the public interface method in that case.
* @param beanName the name of the bean to look for
* @return if this bean factory contains a bean definition with the given name
* @see #containsBean
* @see org.springframework.beans.factory.ListableBeanFactory#containsBeanDefinition
*/
protected abstract boolean containsBeanDefinition(String beanName);

/**
* Return the bean definition for the given bean name.
* Subclasses should normally implement caching, as this method is invoked
* by this class every time bean definition metadata is needed.
* <p>Depending on the nature of the concrete bean factory implementation,
* this operation might be expensive (for example, because of directory lookups
* in external registries). However, for listable bean factories, this usually
* just amounts to a local hash lookup: The operation is therefore part of the
* public interface there. The same implementation can serve for both this
* template method and the public interface method in that case.
* @param beanName the name of the bean to find a definition for
* @return the BeanDefinition for this prototype name (never {@code null})
* @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
* if the bean definition cannot be resolved
* @throws BeansException in case of errors
* @see RootBeanDefinition
* @see ChildBeanDefinition
* @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory#getBeanDefinition
*/
protected abstract BeanDefinition getBeanDefinition(String beanName) throws BeansException;

/**
* Create a bean instance for the given merged bean definition (and arguments).
* The bean definition will already have been merged with the parent definition
* in case of a child definition.
* <p>All bean retrieval methods delegate to this method for actual bean creation.
* @param beanName the name of the bean
* @param mbd the merged bean definition for the bean
* @param args explicit arguments to use for constructor or factory method invocation
* @return a new instance of the bean
* @throws BeanCreationException if the bean could not be created
*/
protected abstract Object createBean(String beanName, RootBeanDefinition mbd, Object[] args)
throws BeanCreationException;

}