Spring的refresh()方法調用過程
refresh()是Spring中比較核心的方法，Spring所有的初始化都在這個方法中完成
具體代碼如下

public void refresh() throws BeansException, IllegalStateException {synchronized (this.startupShutdownMonitor) {// Prepare this context for refreshing.prepareRefresh();// Tell the subclass to refresh the internal bean factory.ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();// Prepare the bean factory for use in this context.prepareBeanFactory(beanFactory);try {// Allows post-processing of the bean factory in context subclasses.postProcessBeanFactory(beanFactory);// Invoke factory processors registered as beans in the context.invokeBeanFactoryPostProcessors(beanFactory);// Register bean processors that intercept bean creation.registerBeanPostProcessors(beanFactory);// Initialize message source for this context.initMessageSource();// Initialize event multicaster for this context.initApplicationEventMulticaster();// Initialize other special beans in specific context subclasses.onRefresh();// Check for listener beans and register them.registerListeners();// Instantiate all remaining (non-lazy-init) singletons.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;}}}

Spring中refresh調用過程
//準備工作包括設置啟動時間，是否激活標識位，初始化屬性源(property source)配置

prepareRefresh();

//創建beanFactory（過程是根據xml為每個bean生成BeanDefinition并注冊到生成的beanFactory）

ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

//準備創建好的beanFactory（給beanFactory設置ClassLoader，設置SpEL表達式解析器，設置類型轉化器【能將xml String類型轉成相應對象】，增加內置ApplicationContextAwareProcessor對象，忽略各種Aware對象，注冊各種內置的對賬對象【BeanFactory，ApplicationContext】等，注冊AOP相關的一些東西，注冊環境相關的一些bean

prepareBeanFactory(ConfigurableListableBeanFactory beanFactory)

//實例化并調用BeanFactory中擴展了BeanFactoryPostProcessor的Bean的postProcessBeanFactory方法

invokeBeanFactoryPostProcessors(beanFactory);

//實例化和注冊beanFactory中擴展了BeanPostProcessor的bean

registerBeanPostProcessors(beanFactory)方法;

//實例化，注冊和設置國際化工具類MessageSource

initMessageSource();

//實例化，注冊和設置消息廣播類（如果沒有自己定義使用默認的SimpleApplicationEventMulticaster實現，此廣播使用同步的通知方式）

initApplicationEventMulticaster();

//設置樣式工具ThemeSource

onRefresh();

//添加用戶定義的消息接收器到上面設置的消息廣播ApplicationEventMulticaster

registerListeners();

//設置自定義的類型轉化器ConversionService，設置自定義AOP相關的類LoadTimeWeaverAware，清除臨時的ClassLoader，凍結配置（沒看明白干什么的），實例化所有的類（懶加載的類除外）

finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory);

//注冊和設置跟bean生命周期相關的類（默認使用DefaultLifecycleProcessor），調用擴展了SmartLifecycle接口的start方法，使用上注冊的廣播類消息廣播類ApplicationEventMulticaster廣播ContextRefreshedEvent事件

finishRefresh();