Spring源码情操陶冶-AbstractApplicationContext

前言-阅读源码有利于陶冶情操，本文承接前文Spring源码情操陶冶-ContextLoader

约束：本文指定contextClass为默认的XmlWebApplicationContext

AbstractApplicationContext#refresh()

简单看下refresh()方法内罗列的一系列方法，代码清单如下

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) {
				// Destroy already created singletons to avoid dangling resources.
				destroyBeans();

				// Reset 'active' flag.
				cancelRefresh(ex);

				// Propagate exception to caller.
				throw ex;
			}
		}
	}

针对上述的代码逻辑，为了避免代码的凌乱以及放在同篇文章文字过长，遂作如下链接导航

• AbstractApplicationContext#prepareRefresh
  
  刷新准备工作，@prepareRefresh

• AbstractApplicationContext#obtainFreshBeanFactory
  
  涉及解析spring配置文件并封装为BeanDefinition对象保存至beanFactory中，@obtainFreshBeanFactory

• AbstractApplicationContext#prepareBeanFactory
  
  beanFactory的准备工作，设置context的属性配置，@prepareBeanFactory

• AbstractApplicationContext#postProcessBeanFactory
  
  主要添加ServletContextAwareProcessor处理类，@postProcessBeanFactory

• AbstractApplicationContext#invokeBeanFactoryPostProcessors
  
  执行BeanDefinitionRegistryPostProcessors/BeanFactoryPostProcessors相关beans，@invokeBeanFactoryPostProcessors

• AbstractApplicationContext#registerBeanPostProcessors
  
  注册所有实现BeanPostProcessor的接口bean到beanFactory的内部属性beanPostProcessors集合中，@registerBeanPostProcessors

• AbstractApplicationContext#initMessageSource
  
  初始化资源配置，@initMessageSource

• AbstractApplicationContext#initApplicationEventMulticaster
  
  初始化ApplictionEventMulticaster广播事件类，@initApplicationEventMulticaster

• AbstractApplicationContext#onRefresh
  
  初始化themeSource，@onRefresh

• AbstractApplicationContext#registerListeners
  
  注册ApplicationListener beans到ApplictionEventMulticaster广播集合，@registerListeners

• AbstractApplicationContext#finishBeanFactoryInitialization
  
  实例化所有的非lazy-init类型的beans，@finishBeanFactoryInitialization

• AbstractApplicationContext#finishRefresh
  
  完成刷新，并执行ContextRefreshedEvent事件，该事件涉及spring mvc，@finishRefresh

结束语

阅读源码的目的是为了了解其运行的机制，但可能涵盖的内容过广，可以对有兴趣的地方进行深刻的源码追踪，并理解其中的代码设计，不为是一件快乐的事情