对于想要拥有自动装配能力，并且想把这种能力暴露给外部引用的BeanFactory类需要实现此接口。正常情况下，不要使用此接口应该更倾向于使用BeanFactory或者ListableBeanFactory接口。
/* * Copyright 2002-2016 the original author or authors.
* * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.beans.factory.config; import java.util.Set; import org.springframework.beans.BeansException; import org.springframework.beans.TypeConverter; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.beans.factory.NoUniqueBeanDefinitionException; /**
此接口主要是针对框架之外，没有向spring托管Bean的应用，通过暴露此功能，spring框架之外的程序，具有自动装配等spring的功能。
需要注意的是，ApplicationContext接口并没有实现此接口，因为应用代码很少用到此功能，如果确实需要的话，可以调用ApplicationContext的
getAutowireCapableBeanFactory方法，来获取此接口的实例。如果一个类实现了此接口，那么很大程序上它还需要实现BeanFactoryAware接口
它可以在应用上下文中返回BeanFactory
* * @author Juergen Hoeller * @since 04.12.2003 * @see org.springframework.beans.factory.BeanFactoryAware * @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory * @see org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory() */ public interface AutowireCapableBeanFactory extends BeanFactory { /** * Constant that indicates no externally defined autowiring. Note that * BeanFactoryAware etc and annotation-driven injection will still be applied.
常量，用于表示外部自动装配功能是否可用 ，但是此标识不影响正常的（基于注解的等）自动装配功能 * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_NO = 0; /** * Constant that indicates autowiring bean properties by name * (applying to all bean property setters).
常量，表示按照名称自动装配bean属性（适用于所有bean属性设置器） * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_BY_NAME = 1; /** * Constant that indicates autowiring bean properties by type * (applying to all bean property setters).
常量，表示按类型自动装配bean属性（适用于所有bean属性设置器） * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_BY_TYPE = 2; /** * Constant that indicates autowiring the greediest constructor that * can be satisfied (involves resolving the appropriate constructor).
常量，表示按照贪婪策略匹配出最符合的构造方法来自动装配（） * @see #createBean * @see #autowire */ int AUTOWIRE_CONSTRUCTOR = 3; /** * Constant that indicates determining an appropriate autowire strategy * through introspection of the bean class.
常量，表示自动识别一种装配策略来自动装配的常量 * @see #createBean * @see #autowire * @deprecated as of Spring 3.0: If you are using mixed autowiring strategies, * prefer annotation-based autowiring for clearer demarcation of autowiring needs. */ @Deprecated int AUTOWIRE_AUTODETECT = 4; //------------------------------------------------------------------------- // Typical methods for creating and populating external bean instances //------------------------------------------------------------------------- /** * Fully create a new bean instance of the given class. * <p>Performs full initialization of the bean, including all applicable * {@link BeanPostProcessor BeanPostProcessors}. * <p>Note: This is intended for creating a fresh instance, populating annotated * fields and methods as well as applying all standard bean initialization callbacks. * It does <i>not</> imply traditional by-name or by-type autowiring of properties; * use {@link #createBean(Class, int, boolean)} for those purposes. * @param beanClass the class of the bean to create * @return the new bean instance * @throws BeansException if instantiation or wiring failed
创建一个给定Class的实例。
执行此Bean所有的关于Bean生命周期的接口方法如BeanPostProcessor
此方法用于创建一个新实例，它会处理各种带有注解的域和方法，并且会调用所有bean初始化时所需要调用的回调函数
* 此方法并不意味着by-name或者by-type方式的自动装配，如果需要使用这写功能，可以使用其重载方法
*/ <T> T createBean(Class<T> beanClass) throws BeansException; /** * Populate the given bean instance through applying after-instantiation callbacks * and bean property post-processing (e.g. for annotation-driven injection).
通过调用给定bean的after-instantiation及post-processing接口，对bean进行配置。 * <p>Note: This is essentially intended for (re-)populating annotated fields and * methods,
此方法主要是用于处理Bean中带有注解的域和方法
either for new instances or for deserialized instances. It does * <i>not</i> imply traditional by-name or by-type autowiring of properties; * use {@link #autowireBeanProperties} for those purposes.
此方法并不意味着by-name或者by-type方式的自动装配，如果需要使用这些功能，可以使用其重载方法autowireBeanProperties * @param existingBean the existing bean instance * @throws BeansException if wiring failed
*/ void autowireBean(Object existingBean) throws BeansException; /** * Configure the given raw bean: autowiring bean properties, applying * bean property values, applying factory callbacks such as {@code setBeanName} * and {@code setBeanFactory}, and also applying all bean post processors * (including ones which might wrap the given raw bean).
配置参数中指定的bean，包括自动装配其域，对其应用如setBeanName功能的回调函数。
并且会调用其所有注册的post processor。
* <p>This is effectively a superset of what {@link #initializeBean} provides, * fully applying the configuration specified by the corresponding bean definition.
此方法提供的功能是initializeBean方法的超集，会应用所有注册在bean defineneition中的操作
不过需要BeanFactory中有参数中指定名字的BeanDefinition.
* <b>Note: This method requires a bean definition for the given name!</b> * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (a bean definition of that name has to be available) * @return the bean instance to use, either the original or a wrapped one * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException * if there is no bean definition with the given name * @throws BeansException if the initialization failed * @see #initializeBean */ Object configureBean(Object existingBean, String beanName) throws BeansException; //------------------------------------------------------------------------- // Specialized methods for fine-grained control over the bean lifecycle //------------------------------------------------------------------------- /** * Fully create a new bean instance of the given class with the specified * autowire strategy. All constants defined in this interface are supported here. * <p>Performs full initialization of the bean, including all applicable * {@link BeanPostProcessor BeanPostProcessors}. This is effectively a superset * of what {@link #autowire} provides, adding {@link #initializeBean} behavior. * @param beanClass the class of the bean to create * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for objects * (not applicable to autowiring a constructor, thus ignored there) * @return the new bean instance * @throws BeansException if instantiation or wiring failed * @see #AUTOWIRE_NO * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_CONSTRUCTOR
创建一个指定class的实例，通过参数可以指定其自动装配模式（by-name or by-type）.
会执行所有注册在此class上用以初始化bean的方法.如BeanPostProcessors等
*/ Object createBean(Class<?> beanClass, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Instantiate a new bean instance of the given class with the specified autowire * strategy. All constants defined in this interface are supported here. * Can also be invoked with {@code AUTOWIRE_NO} in order to just apply * before-instantiation callbacks (e.g. for annotation-driven injection). * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the construction of the instance. * @param beanClass the class of the bean to instantiate * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for object * references in the bean instance (not applicable to autowiring a constructor, * thus ignored there) * @return the new bean instance * @throws BeansException if instantiation or wiring failed * @see #AUTOWIRE_NO * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_CONSTRUCTOR * @see #AUTOWIRE_AUTODETECT * @see #initializeBean * @see #applyBeanPostProcessorsBeforeInitialization * @see #applyBeanPostProcessorsAfterInitialization
创建一个指定Class的实例，通过参数可以指定其自动装配模式（by-name or by-type）
会执行所有注册在此class上用以初始化bean的方法。如BeanPostProcessors等
*/ Object autowire(Class<?> beanClass, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Autowire the bean properties of the given bean instance by name or type. * Can also be invoked with {@code AUTOWIRE_NO} in order to just apply * after-instantiation callbacks (e.g. for annotation-driven injection). * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the configuration of the instance. * @param existingBean the existing bean instance * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for object * references in the bean instance * @throws BeansException if wiring failed * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_NO
通过指定的自动装配方式来对给定的Bean进行自动装配
不过会调用指定bean注册的beanPostProcessors等回调函数来初始化Bean
如果指定装配方式AUTOWIRE_NO的话，不会自动装配属性，但是依然会调用BeanPiostProcesser等回调方法
*/ void autowireBeanProperties(Object existingBean, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Apply the property values of the bean definition with the given name to * the given bean instance. The bean definition can either define a fully * self-contained bean, reusing its property values, or just property values * meant to be used for existing bean instances. * <p>This method does <i>not</i> autowire bean properties; it just applies * explicitly defined property values. Use the {@link #autowireBeanProperties} * method to autowire an existing bean instance. * <b>Note: This method requires a bean definition for the given name!</b> * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the configuration of the instance. * @param existingBean the existing bean instance * @param beanName the name of the bean definition in the bean factory * (a bean definition of that name has to be available) * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException * if there is no bean definition with the given name * @throws BeansException if applying the property values failed * @see #autowireBeanProperties
讲参数中指定的那个bean，注入给定实力当中
此方法不会自动注入bean的属性，它仅仅会应用在显式定义的属性之上。如果需要自动注入Bean属性，
autowierBeanProperties方法
此方法需要BeanFactory中存在指定名字的Bean。除了InstantiationAwareBeanPostProcessor的回调函数外
此方法不会再bean上应用其它的例如BeanPostProcessors
等回调方法。不过可以调用其它诸如initializeBean等方法来达到目的
*/ void applyBeanPropertyValues(Object existingBean, String beanName) throws BeansException; /** * Initialize the given raw bean, applying factory callbacks * such as {@code setBeanName} and {@code setBeanFactory}, * also applying all bean post processors (including ones which * might wrap the given raw bean). * <p>Note that no bean definition of the given name has to exist * in the bean factory. The passed-in bean name will simply be used * for callbacks but not checked against the registered bean definitions. * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (only passed to {@link BeanPostProcessor BeanPostProcessors}) * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if the initialization failed
初始化参数中指定的bean,调用任何其注册的回调函数如setBean,setBeanFactory等。
另外还会调用此Bean上的所有PostProcessors方法
*/ Object initializeBean(Object existingBean, String beanName) throws BeansException; /** * Apply {@link BeanPostProcessor BeanPostProcessors} to the given existing bean * instance, invoking their {@code postProcessBeforeInitialization} methods. * The returned bean instance may be a wrapper around the original. * @param existingBean the new bean instance * @param beanName the name of the bean * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if any post-processing failed * @see BeanPostProcessor#postProcessBeforeInitialization
调用参数中指定bean的postProcessBeforeInitialization方法 */ Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName) throws BeansException; /** * Apply {@link BeanPostProcessor BeanPostProcessors} to the given existing bean * instance, invoking their {@code postProcessAfterInitialization} methods. * The returned bean instance may be a wrapper around the original. * @param existingBean the new bean instance * @param beanName the name of the bean * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if any post-processing failed * @see BeanPostProcessor#postProcessAfterInitialization
调用参数中指定bean的postProcessAfterInitialization方法 */ Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName) throws BeansException; /** * Destroy the given bean instance (typically coming from {@link #createBean}), * applying the {@link org.springframework.beans.factory.DisposableBean} contract as well as * registered {@link DestructionAwareBeanPostProcessor DestructionAwareBeanPostProcessors}. * <p>Any exception that arises during destruction should be caught * and logged instead of propagated to the caller of this method. * @param existingBean the bean instance to destroy
销毁参数中给定的bean，同时调用此bean上的DisposableBean和DestructionAwareBeanPostProce
在销毁途中，任何的异常情况都只应该被捕获和记录，而不应该向外抛出。
*/ void destroyBean(Object existingBean); //------------------------------------------------------------------------- // Delegate methods for resolving injection points //------------------------------------------------------------------------- /** * Resolve the bean instance that uniquely matches the given object type, if any, * including its bean name. * <p>This is effectively a variant of {@link #getBean(Class)} which preserves the * bean name of the matching instance. * @param requiredType type the bean must match; can be an interface or superclass. * {@code null} is disallowed. * @return the bean name plus bean instance * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if the bean could not be created * @since 4.3.3 * @see #getBean(Class)
查找唯一符合指定类的实例，如果有，则返回实例的名字和实例本身和beanFactory中的getBean（class）方法类似，
只不过多加了一个bean的名字
*/ <T> NamedBeanHolder<T> resolveNamedBean(Class<T> requiredType) throws BeansException; /** * Resolve the specified dependency against the beans defined in this factory. * @param descriptor the descriptor for the dependency (field/method/constructor) * @param requestingBeanName the name of the bean which declares the given dependency * @return the resolved object, or {@code null} if none found * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if dependency resolution failed for any other reason * @since 2.5 * @see #resolveDependency(DependencyDescriptor, String, Set, TypeConverter)
解析出在Factory中与指定bean有指定依赖关系的bean */ Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName) throws BeansException; /** * Resolve the specified dependency against the beans defined in this factory.
解析指定bean在Factory中的依赖关系 * @param descriptor the descriptor for the dependency (field/method/constructor)
依赖描述（field/method/constructor） * @param requestingBeanName the name of the bean which declares the given dependency
依赖描述所属的Bean * @param autowiredBeanNames a Set that all names of autowired beans (used for * resolving the given dependency) are supposed to be added to
autowireBeanNames 与指定bean有依赖关系的Bean * @param typeConverter the TypeConverter to use for populating arrays and collections
用以转换数组和连表的转换器 * @return the resolved object, or {@code null} if none found
解析结果，可能为null * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if dependency resolution failed for any other reason * @since 2.5 * @see DependencyDescriptor
*/ Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName, Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException; }
学习参考原创的网址：https://blog.csdn.net/weixin_39165515/article/details/77096774