Spring源码解析（一）-BeanFactory和FactoryBean

本系列博客针对Spring4.2.4版本，参考《Spring技术内幕》第2版

BeanFactory

BeanFactory是最基本的IOC容器接口，这个接口为具体的IOC容器的实现作了最基本的功能规定

BeanFactory类结构体系

BeanFactory结构体系.png

BeanFactory类详解

public interface BeanFactory {

    //这里是对FactoryBean的转义定义，因为如果使用bean的名字检索    FactoryBean得到的对象是工厂生成的对象，  
    //如果需要得到工厂本身，加上“&”
    String FACTORY_BEAN_PREFIX = "&";

    //根据bean的名字，在IOC容器中得到bean实例
    Object getBean(String name) throws BeansException;

    //根据bean的名字和Class类型来得到bean实例，若根据名字取得的bean实例的Class类型和需要的不同的话
    //会抛出异常
     T getBean(String name, Class requiredType) throws BeansException;

    //根据指定的类型取得IoC容器中管理的Bean
     T getBean(Class requiredType) throws BeansException;

    //重载了getBean(String name)方法，可变参数用来指定构造方法或者工厂方法需要的参数
    //覆盖之前已经在bean中定义好的参数
    Object getBean(String name, Object... args) throws BeansException;

    //重载了getBean(Class requiredType)方法，可变参数用来指定构造方法或者工厂方法需要的参数
    //覆盖之前已经在bean中定义好的参数
     T getBean(Class requiredType, Object... args) throws BeansException;

    //判断在IOC容器是否 有这个名字的bean
    boolean containsBean(String name);

    //查询指定名字的Bean是否是单态类型(singleton)
    boolean isSingleton(String name) throws NoSuchBeanDefinitionException;

    //查询指定名字的Bean是否是原型(prototype)类型
    boolean isPrototype(String name) throws NoSuchBeanDefinitionException;

    //查询指定名字的Bean的class类型是否支持特定的class类型
    boolean isTypeMatch(String name, Class targetType) throws NoSuchBeanDefinitionException;

    //查询指定名字的Bean的class类型
    Class getType(String name) throws NoSuchBeanDefinitionException;

    //查询指定名字的Bean的所有别名
    String[] getAliases(String name);

}

生命周期

 * 
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:

 * 1. BeanNameAware's {@code setBeanName}

 * 2. BeanClassLoaderAware's {@code setBeanClassLoader}

 * 3. BeanFactoryAware's {@code setBeanFactory}

 * 4. ResourceLoaderAware's {@code setResourceLoader}
 * (only applicable when running in an application context)

 * 5. ApplicationEventPublisherAware's {@code setApplicationEventPublisher}
 * (only applicable when running in an application context)

 * 6. MessageSourceAware's {@code setMessageSource}
 * (only applicable when running in an application context)

 * 7. ApplicationContextAware's {@code setApplicationContext}
 * (only applicable when running in an application context)

 * 8. ServletContextAware's {@code setServletContext}
 * (only applicable when running in a web application context)

 * 9. {@code postProcessBeforeInitialization} methods of BeanPostProcessors

 * 10. InitializingBean's {@code afterPropertiesSet}

 * 11. a custom init-method definition

 * 12. {@code postProcessAfterInitialization} methods of BeanPostProcessors
 *
 * 
On shutdown of a bean factory, the following lifecycle methods apply:

 * 1. DisposableBean's {@code destroy}

 * 2. a custom destroy-method definition

BeanFactory和FactoryBean的区别和联系

BeanFactory是spring容器的根容器，描述了子接口（子容器）的一些处理原则，包括一些生命周期，方法和约定。FactoryBean本身是存活在IOC容器（BeanFactory）中，本身也是一个工厂，用于创建由FactoryBean所能创建出来的对象，再创建出该对象时，可以对该对象的后面或者前面做一些额外的操作来实现AOP。