Spring源码阅读--AbstractApplicationContext refresh()方法调用

Spring初始化Ioc容器很重要的一个方法是由ApplicationContext子接口ConfigurableApplicationContext提供的refresh(),这个方法的作用是创建加载Spring容器配置（包括.xml配置，property文件和数据库模式等）。下面是各个refresh()调用的各个方法的作用解析：

@Overridepublic void refresh() throws BeansException, IllegalStateException {synchronized (this.startupShutdownMonitor) {// Prepare this context for refreshing.prepareRefresh();// Tell the subclass to refresh the internal bean factory.//主要是创建beanFactory，同时加载配置文件.xml中的beanDefinition//通过String[] configLocations = getConfigLocations()获取资源路径，然后加载beanDefinitionConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();// Prepare the bean factory for use in this context.//给beanFactory注册一些标准组建，如ClassLoader，StandardEnvironment，BeanProcessprepareBeanFactory(beanFactory);try {// Allows post-processing of the bean factory in context subclasses.//提供给子类实现一些postProcess的注册，如AbstractRefreshableWebApplicationContext注册一些Servlet相关的//postProcess，真对web进行生命周期管理的Scope，通过registerResolvableDependency()方法注册指定ServletRequest，HttpSession，WebRequest对象的工厂方法postProcessBeanFactory(beanFactory);// Invoke factory processors registered as beans in the context.//调用所有BeanFactoryProcessor的postProcessBeanFactory()方法invokeBeanFactoryPostProcessors(beanFactory);// Register bean processors that intercept bean creation.//注册BeanPostProcessor，BeanPostProcessor作用是用于拦截Bean的创建registerBeanPostProcessors(beanFactory);// Initialize message source for this context.//初始化消息BeaninitMessageSource();// Initialize event multicaster for this context.//初始化上下文的事件多播组建，ApplicationEvent触发时由multicaster通知给ApplicationListenerinitApplicationEventMulticaster();// Initialize other special beans in specific context subclasses.//ApplicationContext初始化一些特殊的beanonRefresh();// Check for listener beans and register them.//注册事件监听器，事件监听Bean统一注册到multicaster里头，ApplicationEvent事件触发后会由multicaster广播registerListeners();// Instantiate all remaining (non-lazy-init) singletons.//非延迟加载的单例Bean实例化finishBeanFactoryInitialization(beanFactory);// Last step: publish corresponding event.finishRefresh();}catch (BeansException ex) {logger.warn("Exception encountered during context initialization - cancelling refresh attempt", ex);// Destroy already created singletons to avoid dangling resources.destroyBeans();// Reset 'active' flag.cancelRefresh(ex);// Propagate exception to caller.throw ex;}}}