spring源码学习（八）容器功能拓展

我们在项目上常用的一般是ClassPathXmlApplicationContext这个类.

    public ClassPathXmlApplicationContext(            String[] configLocations, boolean refresh, @Nullable ApplicationContext parent)            throws BeansException {        super(parent);        setConfigLocations(configLocations);        if (refresh) {            refresh();        }    }    public void setConfigLocations(@Nullable String... locations) {        if (locations != null) {            Assert.noNullElements(locations, "Config locations must not be null");            this.configLocations = new String[locations.length];            for (int i = 0; i < locations.length; i++) {                this.configLocations[i] = resolvePath(locations[i]).trim();            }        }        else {            this.configLocations = null;        }    }    @Override    public void refresh() throws BeansException, IllegalStateException {        synchronized (this.startupShutdownMonitor) {            // Prepare this context for refreshing.            //准备刷新的上下文环境            prepareRefresh();            // Tell the subclass to refresh the internal bean factory.            //初始化BeanFactory，进行Xml文件获取            ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();            // Prepare the bean factory for use in this context.            //对BeanFactory进行各种功能填充            prepareBeanFactory(beanFactory);            try {                // Allows post-processing of the bean factory in context subclasses.                //子类覆盖方法做额外处理                postProcessBeanFactory(beanFactory);                // Invoke factory processors registered as beans in the context.                //激活各种BeanFactory处理器                invokeBeanFactoryPostProcessors(beanFactory);                // Register bean processors that intercept bean creation.                //注册拦截Bean创建的Bean处理器，这里只是注册，真正的调用在getBean                registerBeanPostProcessors(beanFactory);                // Initialize message source for this context.                //为上下文初始化Message源，即国际化                initMessageSource();                // Initialize event multicaster for this context.                //初始化应用消息广播器                initApplicationEventMulticaster();                // Initialize other special beans in specific context subclasses.                //留给子类来初始化其他的Bean                onRefresh();                // Check for listener beans and register them.                //在所有注册的bean中查找Listener bran                registerListeners();                // Instantiate all remaining (non-lazy-init) singletons.                //初始化剩下的单实例                finishBeanFactoryInitialization(beanFactory);                // Last step: publish corresponding event.                //完成刷新过程，通知生命周期处理器lifecycleProcessor刷新                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();            }        }    }

在ClassPathXmlApplicationContext中，做了很多功能上的拓展，增加了spel语言支持，增加了属性注册编辑器，添加了ApplicationContext AwreProcessor处理器，设置依赖忽略和注册依赖，BeanFactory的后处理等，但是核心的东西依然和XmlBeanFactory中相同，所以就不在深入查看源代码了，之后会看一下spring AOP的源码，以后有时间的话会在重新把这里的源码补全。