• Spring BeanFactory源码学习


    一.BeanFactory

      BeanFactory是Spring IOC容器的基础,是IOC容器的基础接口,所有的容器都是从它这里继承实现而来。BeanFactory提供了最基本的IOC容器的功能,即所有的容器至少需要实现的标准。BeanFactory体系结构是典型的工厂方法模式,即什么样的工厂生产什么样的产品。BeanFactory是最基本的抽象工厂,而其他的IOC容器只不过是具体的工厂,对应着各自的Bean定义方法。但同时,其他容器也针对具体场景不同,进行了扩充,提供具体的服务。

    二.BeanFacory源码

    1.java doc

      首先是Java doc,现在阅读源码的习惯是一定要理解了java doc的描述,因为这里是作者的描述,没有人比作者更明白这个类,这个接口要干什么。

    /**
     * The root interface for accessing a Spring bean container.
     * This is the basic client view of a bean container;
     * further interfaces such as {@link ListableBeanFactory} and
     * {@link org.springframework.beans.factory.config.ConfigurableBeanFactory}
     * are available for specific purposes.
     *
     * <p>This interface is implemented by objects that hold a number of bean definitions,
     * each uniquely identified by a String name. Depending on the bean definition,
     * the factory will return either an independent instance of a contained object
     * (the Prototype design pattern), or a single shared instance (a superior
     * alternative to the Singleton design pattern, in which the instance is a
     * singleton in the scope of the factory). Which type of instance will be returned
     * depends on the bean factory configuration: the API is the same. Since Spring
     * 2.0, further scopes are available depending on the concrete application
     * context (e.g. "request" and "session" scopes in a web environment).
     *
     * <p>The point of this approach is that the BeanFactory is a central registry
     * of application components, and centralizes configuration of application
     * components (no more do individual objects need to read properties files,
     * for example). See chapters 4 and 11 of "Expert One-on-One J2EE Design and
     * Development" for a discussion of the benefits of this approach.
     *
     * <p>Note that it is generally better to rely on Dependency Injection
     * ("push" configuration) to configure application objects through setters
     * or constructors, rather than use any form of "pull" configuration like a
     * BeanFactory lookup. Spring's Dependency Injection functionality is
     * implemented using this BeanFactory interface and its subinterfaces.
     *
     * <p>Normally a BeanFactory will load bean definitions stored in a configuration
     * source (such as an XML document), and use the {@code org.springframework.beans}
     * package to configure the beans. However, an implementation could simply return
     * Java objects it creates as necessary directly in Java code. There are no
     * constraints on how the definitions could be stored: LDAP, RDBMS, XML,
     * properties file, etc. Implementations are encouraged to support references
     * amongst beans (Dependency Injection).
     *
     * <p>In contrast to the methods in {@link ListableBeanFactory}, all of the
     * operations in this interface will also check parent factories if this is a
     * {@link HierarchicalBeanFactory}. If a bean is not found in this factory instance,
     * the immediate parent factory will be asked. Beans in this factory instance
     * are supposed to override beans of the same name in any parent factory.
     *
     * <p>Bean factory implementations should support the standard bean lifecycle interfaces
     * as far as possible. The full set of initialization methods and their standard order is:<br>
     * 1. BeanNameAware's {@code setBeanName}<br>
     * 2. BeanClassLoaderAware's {@code setBeanClassLoader}<br>
     * 3. BeanFactoryAware's {@code setBeanFactory}<br>
     * 4. ResourceLoaderAware's {@code setResourceLoader}
     * (only applicable when running in an application context)<br>
     * 5. ApplicationEventPublisherAware's {@code setApplicationEventPublisher}
     * (only applicable when running in an application context)<br>
     * 6. MessageSourceAware's {@code setMessageSource}
     * (only applicable when running in an application context)<br>
     * 7. ApplicationContextAware's {@code setApplicationContext}
     * (only applicable when running in an application context)<br>
     * 8. ServletContextAware's {@code setServletContext}
     * (only applicable when running in a web application context)<br>
     * 9. {@code postProcessBeforeInitialization} methods of BeanPostProcessors<br>
     * 10. InitializingBean's {@code afterPropertiesSet}<br>
     * 11. a custom init-method definition<br>
     * 12. {@code postProcessAfterInitialization} methods of BeanPostProcessors
     *
     * <p>On shutdown of a bean factory, the following lifecycle methods apply:<br>
     * 1. DisposableBean's {@code destroy}<br>
     * 2. a custom destroy-method definition
    View Code

      在BeanFactory里只对IOC容器的基本行为作了定义,根本不关心你的bean是如何定义怎样加载的。正如我们只关心工厂里得到什么的产品对象,至于工厂是怎么生产这些对象的,这个基本的接口不关心。

    2.源码

    public interface BeanFactory {
        /**
         * Used to dereference a {@link FactoryBean} instance and distinguish it from
         * beans <i>created</i> by the FactoryBean. For example, if the bean named
         * {@code myJndiObject} is a FactoryBean, getting {@code &myJndiObject}
         * will return the factory, not the instance returned by the factory.
         */
        //使用转义符&来得到FactoryBean本身,用来区分通过容器获得FactoryBean本身和其产生的对象
        String FACTORY_BEAN_PREFIX = "&";
    
        //通过name来获取指定的bean
        Object getBean(String name) throws BeansException;
        
        //根据名字和类型来得到bean实例,增加了类型安全验证机制
        <T> T getBean(String name, Class<T> requiredType) throws BeansException;
    
        //通过类型获取bean实例
        <T> T getBean(Class<T> requiredType) throws BeansException;
    
        //增加更多获取的条件,同上方法
        Object getBean(String name, Object... args) throws BeansException;
    
        <T> T getBean(Class<T> requiredType, Object... args) throws BeansException;
    
        //判断容器是否含有指定名字的bean
        boolean containsBean(String name);
    
        //查询指定名字的Bean是不是单例的Bean
        boolean isSingleton(String name) throws NoSuchBeanDefinitionException;
    
        //判断Bean是不是prototype类型的bean
        boolean isPrototype(String name) throws NoSuchBeanDefinitionException;
    
        //查询指定了名字的Bean的Class类型是否与指定类型匹配
        boolean isTypeMatch(String name, Class<?> targetType) throws NoSuchBeanDefinitionException;
       
        //获取指定名字bean的Class类型
        Class<?> getType(String name) throws NoSuchBeanDefinitionException;
    
        //查询指定了名字的bean的所有别名,这些别名都是在BeanDefinition中定义的
        String[] getAliases(String name);
    }
    View Code

      BeanFactory接口定义了IOC容器要实现的基本方法。 

    三. BeanFactory 结构体系

      其中BeanFactory作为最顶层的一个接口类,它定义了IOC容器的基本功能规范,BeanFactory 三个子类:ListableBeanFactory、HierarchicalBeanFactory和AutowireCapableBeanFactory。但是从上图中我们可以发现最终的默认实现类是 DefaultListableBeanFactory,他实现了所有的接口。那为何要定义这么多层次的接口呢?查阅这些接口的源码和说明发现,每个接口都有他使用的场合,它主要是为了区分在 Spring 内部在操作过程中对象的传递和转化过程中,对对象的数据访问所做的限制。例如 ListableBeanFactory 接口表示这些 Bean是可列表的,而 HierarchicalBeanFactory 表示的是这些 Bean 是有继承关系的,也就是每个Bean有可能有父Bean。AutowireCapableBeanFactory 接口定义Bean的自动装配规则。这四个接口共同定义了Bean的集合、Bean之间的关系、以 Bean行为.

    1.AutowireCapableBeanFactory 

    1.1Java doc文档

    /**
     * Extension of the {@link org.springframework.beans.factory.BeanFactory}
     * interface to be implemented by bean factories that are capable of
    autowiring, provided that they want to expose this functionality for
     * existing bean instances.
     *
     * <p>This subinterface of BeanFactory is not meant to be used in normal
     * application code: stick to {@link org.springframework.beans.factory.BeanFactory}
     * or {@link org.springframework.beans.factory.ListableBeanFactory} for
     * typical use cases.
     *
     * <p>Integration code for other frameworks can leverage this interface to
     * wire and populate existing bean instances that Spring does not control
     * the lifecycle of. This is particularly useful for WebWork Actions and
     * Tapestry Page objects, for example.
     *
     * <p>Note that this interface is not implemented by
     * {@link org.springframework.context.ApplicationContext} facades,
     * as it is hardly ever used by application code. That said, it is available
     * from an application context too, accessible through ApplicationContext's
     * {@link org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory()}
     * method.
     *
     * <p>You may also implement the {@link org.springframework.beans.factory.BeanFactoryAware}
     * interface, which exposes the internal BeanFactory even when running in an
     * ApplicationContext, to get access to an AutowireCapableBeanFactory:
     * simply cast the passed-in BeanFactory to AutowireCapableBeanFactory.
    org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory()
     */
    View Code

      这个工厂接口继承自BeanFacotory,它扩展了自动装配的功能,根据类定义BeanDefinition装配Bean、执行前、后处理器等。主要用它来管理ApplicationContext所不能管理的那些Bean,比如Filter,Servlet等。主要通过ApplicationContext的getAutowireCapableBeanFactory()获得实例。

    1.2源码

    public interface AutowireCapableBeanFactory extends BeanFactory {
    
        /**
         * Constant that indicates no externally defined autowiring. Note that
         * BeanFactoryAware etc and annotation-driven injection will still be applied.
         * @see #createBean
         * @see #autowire
         * @see #autowireBeanProperties
         */
        int AUTOWIRE_NO = 0;
    
        /**
         * Constant that indicates autowiring bean properties by name
         * (applying to all bean property setters).
         * @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).
         * @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).
         * @see #createBean
         * @see #autowire
         */
        int AUTOWIRE_CONSTRUCTOR = 3;
    
        /**
         * Constant that indicates determining an appropriate autowire strategy
         * through introspection of the bean class.
         * @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 initialiation callbacks.
         * It does <i>not</> imply traditional by-name or by-type autowiring of properties;
         * use {@link #createBean(Class, int, boolean)} for that purposes.
         * @param beanClass the class of the bean to create
         * @return the new bean instance
         * @throws BeansException if instantiation or wiring failed
         */
        <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).
         * <p>Note: This is essentially intended for (re-)populating annotated fields and
         * methods, 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 that purposes.
         * @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).
         * <p>This is effectively a superset of what {@link #initializeBean} provides,
         * fully applying the configuration specified by the corresponding bean definition.
         * <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;
    
        /**
         * Resolve the specified dependency against the beans defined in this factory.
         * @param descriptor the descriptor for the dependency
         * @param beanName the name of the bean which declares the present dependency
         * @return the resolved object, or {@code null} if none found
         * @throws BeansException in dependency resolution failed
         */
        Object resolveDependency(DependencyDescriptor descriptor, 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
         */
        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
         */
        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
         */
        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
         */
        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
         */
        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
         */
        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
         */
        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
         */
        void destroyBean(Object existingBean);
    
        /**
         * Resolve the specified dependency against the beans defined in this factory.
         * @param descriptor the descriptor for the dependency
         * @param beanName the name of the bean which declares the present dependency
         * @param autowiredBeanNames a Set that all names of autowired beans (used for
         * resolving the present dependency) are supposed to be added to
         * @param typeConverter the TypeConverter to use for populating arrays and
         * collections
         * @return the resolved object, or {@code null} if none found
         * @throws BeansException in dependency resolution failed
         */
        Object resolveDependency(DependencyDescriptor descriptor, String beanName,
                Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException;
    
    }
    View Code

    1.首先几个属性,是装配策略

      AUTOWIRE_BY_NAME:根据名称记性装配。

      AUTOWIRE_BY_TYPE:根据类型进行装配。

      AUTOWIRE_BY_CONSTRUCT:使用构造函数进行装配。

    2.重点关注两类方法

      Typical methods for creating and populating external bean instances。:用于创建和填充外部bean实例的典型方法

      Specialized methods for fine-grained control over the bean lifecycle。专门针对bean生命周期细粒度控制的方法

    2.HierarchicalBeanFactory 

    2.1 JAVA DOC

    package org.springframework.beans.factory;
    
    /**
     * Sub-interface implemented by bean factories that can be part
     * of a hierarchy.
     *
     * <p>The corresponding {@code setParentBeanFactory} method for bean
     * factories that allow setting the parent in a configurable
     * fashion can be found in the ConfigurableBeanFactory interface.
    public interface HierarchicalBeanFactory extends BeanFactory {
        /**
         * Return the parent bean factory, or {@code null} if there is none.
         */
        BeanFactory getParentBeanFactory();
    
        /**
         * Return whether the local bean factory contains a bean of the given name,
         * ignoring beans defined in ancestor contexts.
         * <p>This is an alternative to {@code containsBean}, ignoring a bean
         * of the given name from an ancestor bean factory.
         * @param name the name of the bean to query
         * @return whether a bean with the given name is defined in the local factory
         * @see BeanFactory#containsBean
         */
        boolean containsLocalBean(String name);
    }
    View Code

    3.ListableBeanFactory 

    3.1JAVA DOC

    /**
     * Extension of the {@link BeanFactory} interface to be implemented by bean factories
     * that can enumerate all their bean instances, rather than attempting bean lookup
     * by name one by one as requested by clients. BeanFactory implementations that
     * preload all their bean definitions (such as XML-based factories) may implement
     * this interface.
     *
     * <p>If this is a {@link HierarchicalBeanFactory}, the return values will <i>not</i>
     * take any BeanFactory hierarchy into account, but will relate only to the beans
     * defined in the current factory. Use the {@link BeanFactoryUtils} helper class
     * to consider beans in ancestor factories too.
     *
     * <p>The methods in this interface will just respect bean definitions of this factory.
     * They will ignore any singleton beans that have been registered by other means like
     * {@link org.springframework.beans.factory.config.ConfigurableBeanFactory}'s
     * {@code registerSingleton} method, with the exception of
     * {@code getBeanNamesOfType} and {@code getBeansOfType} which will check
     * such manually registered singletons too. Of course, BeanFactory's {@code getBean}
     * does allow transparent access to such special beans as well. However, in typical
     * scenarios, all beans will be defined by external bean definitions anyway, so most
     * applications don't need to worry about this differentiation.
     *
     * <p><b>NOTE:</b> With the exception of {@code getBeanDefinitionCount}
     * and {@code containsBeanDefinition}, the methods in this interface
     * are not designed for frequent invocation. Implementations may be slow.
     */
    View Code

    总结一下:

      1.从这个工厂接口开始,可以枚举列出工厂可以生产的所有实例。

      2. 而且如果是一个层次继承的工厂,则只会列出当前工厂的实例,而不会列出祖先层的实例。

    3.2源码

    public interface ListableBeanFactory extends BeanFactory {
        /**
         * Check if this bean factory contains a bean definition with the given name.
         * <p>Does not consider any hierarchy this factory may participate in,
         * and ignores any singleton beans that have been registered by
         * other means than bean definitions.
         * @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
         */
        boolean containsBeanDefinition(String beanName);
    
        /**
         * Return the number of beans defined in the factory.
         * <p>Does not consider any hierarchy this factory may participate in,
         * and ignores any singleton beans that have been registered by
         * other means than bean definitions.
         * @return the number of beans defined in the factory
         */
        int getBeanDefinitionCount();
    
        /**
         * Return the names of all beans defined in this factory.
         * <p>Does not consider any hierarchy this factory may participate in,
         * and ignores any singleton beans that have been registered by
         * other means than bean definitions.
         * @return the names of all beans defined in this factory,
         * or an empty array if none defined
         */
        String[] getBeanDefinitionNames();
    
        /**
         * Return the names of beans matching the given type (including subclasses),
         * judging from either bean definitions or the value of {@code getObjectType}
         * in the case of FactoryBeans.
         * <p><b>NOTE: This method introspects top-level beans only.</b> It does <i>not</i>
         * check nested beans which might match the specified type as well.
         * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
         * will get initialized. If the object created by the FactoryBean doesn't match,
         * the raw FactoryBean itself will be matched against the type.
         * <p>Does not consider any hierarchy this factory may participate in.
         * Use BeanFactoryUtils' {@code beanNamesForTypeIncludingAncestors}
         * to include beans in ancestor factories too.
         * <p>Note: Does <i>not</i> ignore singleton beans that have been registered
         * by other means than bean definitions.
         * <p>This version of {@code getBeanNamesForType} matches all kinds of beans,
         * be it singletons, prototypes, or FactoryBeans. In most implementations, the
         * result will be the same as for {@code getBeanNamesForType(type, true, true)}.
         * <p>Bean names returned by this method should always return bean names <i>in the
         * order of definition</i> in the backend configuration, as far as possible.
         * @param type the class or interface to match, or {@code null} for all bean names
         * @return the names of beans (or objects created by FactoryBeans) matching
         * the given object type (including subclasses), or an empty array if none
         * @since 4.2
         * @see FactoryBean#getObjectType
         * @see BeanFactoryUtils#beanNamesForTypeIncludingAncestors(ListableBeanFactory, ResolvableType)
         */
        String[] getBeanNamesForType(ResolvableType type);
    
        /**
         * Return the names of beans matching the given type (including subclasses),
         * judging from either bean definitions or the value of {@code getObjectType}
         * in the case of FactoryBeans.
         * <p><b>NOTE: This method introspects top-level beans only.</b> It does <i>not</i>
         * check nested beans which might match the specified type as well.
         * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
         * will get initialized. If the object created by the FactoryBean doesn't match,
         * the raw FactoryBean itself will be matched against the type.
         * <p>Does not consider any hierarchy this factory may participate in.
         * Use BeanFactoryUtils' {@code beanNamesForTypeIncludingAncestors}
         * to include beans in ancestor factories too.
         * <p>Note: Does <i>not</i> ignore singleton beans that have been registered
         * by other means than bean definitions.
         * <p>This version of {@code getBeanNamesForType} matches all kinds of beans,
         * be it singletons, prototypes, or FactoryBeans. In most implementations, the
         * result will be the same as for {@code getBeanNamesForType(type, true, true)}.
         * <p>Bean names returned by this method should always return bean names <i>in the
         * order of definition</i> in the backend configuration, as far as possible.
         * @param type the class or interface to match, or {@code null} for all bean names
         * @return the names of beans (or objects created by FactoryBeans) matching
         * the given object type (including subclasses), or an empty array if none
         * @see FactoryBean#getObjectType
         * @see BeanFactoryUtils#beanNamesForTypeIncludingAncestors(ListableBeanFactory, Class)
         */
        String[] getBeanNamesForType(Class<?> type);
    
        /**
         * Return the names of beans matching the given type (including subclasses),
         * judging from either bean definitions or the value of {@code getObjectType}
         * in the case of FactoryBeans.
         * <p><b>NOTE: This method introspects top-level beans only.</b> It does <i>not</i>
         * check nested beans which might match the specified type as well.
         * <p>Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
         * which means that FactoryBeans will get initialized. If the object created by the
         * FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
         * type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
         * (which doesn't require initialization of each FactoryBean).
         * <p>Does not consider any hierarchy this factory may participate in.
         * Use BeanFactoryUtils' {@code beanNamesForTypeIncludingAncestors}
         * to include beans in ancestor factories too.
         * <p>Note: Does <i>not</i> ignore singleton beans that have been registered
         * by other means than bean definitions.
         * <p>Bean names returned by this method should always return bean names <i>in the
         * order of definition</i> in the backend configuration, as far as possible.
         * @param type the class or interface to match, or {@code null} for all bean names
         * @param includeNonSingletons whether to include prototype or scoped beans too
         * or just singletons (also applies to FactoryBeans)
         * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
         * <i>objects created by FactoryBeans</i> (or by factory methods with a
         * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
         * eagerly initialized to determine their type: So be aware that passing in "true"
         * for this flag will initialize FactoryBeans and "factory-bean" references.
         * @return the names of beans (or objects created by FactoryBeans) matching
         * the given object type (including subclasses), or an empty array if none
         * @see FactoryBean#getObjectType
         * @see BeanFactoryUtils#beanNamesForTypeIncludingAncestors(ListableBeanFactory, Class, boolean, boolean)
         */
        String[] getBeanNamesForType(Class<?> type, boolean includeNonSingletons, boolean allowEagerInit);
    
        /**
         * Return the bean instances that match the given object type (including
         * subclasses), judging from either bean definitions or the value of
         * {@code getObjectType} in the case of FactoryBeans.
         * <p><b>NOTE: This method introspects top-level beans only.</b> It does <i>not</i>
         * check nested beans which might match the specified type as well.
         * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
         * will get initialized. If the object created by the FactoryBean doesn't match,
         * the raw FactoryBean itself will be matched against the type.
         * <p>Does not consider any hierarchy this factory may participate in.
         * Use BeanFactoryUtils' {@code beansOfTypeIncludingAncestors}
         * to include beans in ancestor factories too.
         * <p>Note: Does <i>not</i> ignore singleton beans that have been registered
         * by other means than bean definitions.
         * <p>This version of getBeansOfType matches all kinds of beans, be it
         * singletons, prototypes, or FactoryBeans. In most implementations, the
         * result will be the same as for {@code getBeansOfType(type, true, true)}.
         * <p>The Map returned by this method should always return bean names and
         * corresponding bean instances <i>in the order of definition</i> in the
         * backend configuration, as far as possible.
         * @param type the class or interface to match, or {@code null} for all concrete beans
         * @return a Map with the matching beans, containing the bean names as
         * keys and the corresponding bean instances as values
         * @throws BeansException if a bean could not be created
         * @since 1.1.2
         * @see FactoryBean#getObjectType
         * @see BeanFactoryUtils#beansOfTypeIncludingAncestors(ListableBeanFactory, Class)
         */
        <T> Map<String, T> getBeansOfType(Class<T> type) throws BeansException;
    
        /**
         * Return the bean instances that match the given object type (including
         * subclasses), judging from either bean definitions or the value of
         * {@code getObjectType} in the case of FactoryBeans.
         * <p><b>NOTE: This method introspects top-level beans only.</b> It does <i>not</i>
         * check nested beans which might match the specified type as well.
         * <p>Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
         * which means that FactoryBeans will get initialized. If the object created by the
         * FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
         * type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
         * (which doesn't require initialization of each FactoryBean).
         * <p>Does not consider any hierarchy this factory may participate in.
         * Use BeanFactoryUtils' {@code beansOfTypeIncludingAncestors}
         * to include beans in ancestor factories too.
         * <p>Note: Does <i>not</i> ignore singleton beans that have been registered
         * by other means than bean definitions.
         * <p>The Map returned by this method should always return bean names and
         * corresponding bean instances <i>in the order of definition</i> in the
         * backend configuration, as far as possible.
         * @param type the class or interface to match, or {@code null} for all concrete beans
         * @param includeNonSingletons whether to include prototype or scoped beans too
         * or just singletons (also applies to FactoryBeans)
         * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
         * <i>objects created by FactoryBeans</i> (or by factory methods with a
         * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
         * eagerly initialized to determine their type: So be aware that passing in "true"
         * for this flag will initialize FactoryBeans and "factory-bean" references.
         * @return a Map with the matching beans, containing the bean names as
         * keys and the corresponding bean instances as values
         * @throws BeansException if a bean could not be created
         * @see FactoryBean#getObjectType
         * @see BeanFactoryUtils#beansOfTypeIncludingAncestors(ListableBeanFactory, Class, boolean, boolean)
         */
        <T> Map<String, T> getBeansOfType(Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
                throws BeansException;
    
        /**
         * Find all names of beans whose {@code Class} has the supplied {@link Annotation}
         * type, without creating any bean instances yet.
         * @param annotationType the type of annotation to look for
         * @return the names of all matching beans
         * @since 4.0
         */
        String[] getBeanNamesForAnnotation(Class<? extends Annotation> annotationType);
    
        /**
         * Find all beans whose {@code Class} has the supplied {@link Annotation} type,
         * returning a Map of bean names with corresponding bean instances.
         * @param annotationType the type of annotation to look for
         * @return a Map with the matching beans, containing the bean names as
         * keys and the corresponding bean instances as values
         * @throws BeansException if a bean could not be created
         * @since 3.0
         */
        Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType) throws BeansException;
    
        /**
         * Find an {@link Annotation} of {@code annotationType} on the specified
         * bean, traversing its interfaces and super classes if no annotation can be
         * found on the given class itself.
         * @param beanName the name of the bean to look for annotations on
         * @param annotationType the annotation class to look for
         * @return the annotation of the given type if found, or {@code null}
         * @throws NoSuchBeanDefinitionException if there is no bean with the given name
         * @since 3.0
         */
        <A extends Annotation> A findAnnotationOnBean(String beanName, Class<A> annotationType)
                throws NoSuchBeanDefinitionException;
    
    }
    View Code
  • 相关阅读:
    zookeeper配置
    redis前端启动和后台启动的区别
    SpringMVC接受JSON参数详解及常见错误总结我改
    SpringMVC @RequestBody接收Json对象字符串
    spring MVC 如何接收前台传入的JSON对象数组
    springMVC 接收json字符串参数
    mysql数据库user表host字段的%问题
    mysql.user表中Host为%的含义
    开店攻略: 零售店铺经营的三大原则
    开店攻略: 如何巧妙接近顾客
  • 原文地址:https://www.cnblogs.com/wxgblogs/p/6659417.html
Copyright © 2020-2023  润新知