基于注解的spring源码解析之读懂refresh方法，refresh方法的总体流程

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基于注解的spring源码解析2-读懂refresh方法

ynchronized (this.startupShutdownMonitor) {
			// Prepare this context for refreshing.
			准备工作包括设置启动时间，是否激活标识位，
			// 初始化属性源(property source)配置
			prepareRefresh();

			// Tell the subclass to refresh the internal bean factory.
			//返回一个factory 为什么需要返回一个工厂
			//因为要对工厂进行初始化
			ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

			// Prepare the bean factory for use in this context.
			//准备工厂
			prepareBeanFactory(beanFactory);

			try {
				// Allows post-processing of the bean factory in context subclasses.

				//这个方法在当前版本的spring是没用任何代码的
				//可能spring期待在后面的版本中去扩展吧
				postProcessBeanFactory(beanFactory);

				// Invoke factory processors registered as beans in the context.
				//在spring的环境中去执行已经被注册的 factory processors
				//设置执行自定义的ProcessBeanFactory 和spring内部自己定义的
				invokeBeanFactoryPostProcessors(beanFactory);

				// Register bean processors that intercept bean creation.
				//注册beanPostProcessor
				registerBeanPostProcessors(beanFactory);

				// Initialize message source for this context.
				initMessageSource();

				// Initialize event multicaster for this context.
				//初始化应用事件广播器
				initApplicationEventMulticaster();

				// Initialize other special beans in specific context subclasses.
				onRefresh();

				// Check for listener beans and register them.
				//注册listener
				registerListeners();

				// Instantiate all remaining (non-lazy-init) singletons.
				finishBeanFactoryInitialization(beanFactory);

				// Last step: publish corresponding event.
				finishRefresh();
			}

			catch (BeansException ex) {
				if (logger.isWarnEnabled()) {
					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;
			}

			finally {
				// Reset common introspection caches in Spring's core, since we
				// might not ever need metadata for singleton beans anymore...
				resetCommonCaches();
			}
		}

prepareRefresh()

这个方法对于spring主线没什么用。

ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

获取beanFactory，获取出来的就是DefaultListableBeanFactory。

prepareBeanFactory(beanFactory)

这个方法主要对beanFactory进行各种属性的赋值，里面增加了两个后置处理器

beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));