一 refresh源码分析
代码语言：javascript复制@Override
public void refresh() throws BeansException, IllegalStateException {
synchronized (this.startupShutdownMonitor) {
// Prepare this context for refreshing.
//准备刷新上下文环境
prepareRefresh();
// Tell the subclass to refresh the internal bean factory.
//初始化beanfactory,并进行xml文件读取
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BeanBeanPostProcessor
registerBeanPostProcessors(beanFactory);
// Initialize message source for this context.
//为上下文初始化message源,即不同语言的消息体,国际化处理.
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.
//留给子类初始化其他bean
onRefresh();
// Check for listener beans and register them.
//在所有注册的bean中查找Listener bean,注册到消息广播器中
registerListeners();
// Instantiate all remaining (non-lazy-init) singletons.
//初始化剩下的单利bean(非惰性)
finishBeanFactoryInitialization(beanFactory);
// Last step: publish corresponding event.
//完成刷新,通知生命周期处理器,同时发出ContextRefreshEvent 通知别人
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();
}
}
}二 prepareBeanFactory 方法源码分析
代码语言：javascript复制 /**
* Configure the factory's standard context characteristics,
* such as the context's ClassLoader and post-processors.
* @param beanFactory the BeanFactory to configure
*/
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
// Tell the internal bean factory to use the context's class loader etc.
//设置beanFactory的classloader为当前context的classLoader
beanFactory.setBeanClassLoader(getClassLoader());
//设置beanFactory的表达式语言处理器,spring3增加了表达式语言的支持
beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
//为beanfactory增加了一个默认的propertyEditor,这个主要针对bean的属性等设置管理的一个工具
beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
// Configure the bean factory with context callbacks.
//添加BeanPostProcessor
beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
//设置需要忽略自动配置接口
beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);
beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
// BeanFactory interface not registered as resolvable type in a plain factory.
// MessageSource registered (and found for autowiring) as a bean.
//设置了几个自动装配的特殊规则
beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
beanFactory.registerResolvableDependency(ResourceLoader.class, this);
beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
beanFactory.registerResolvableDependency(ApplicationContext.class, this);
// Detect a LoadTimeWeaver and prepare for weaving, if found.
if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
// Set a temporary ClassLoader for type matching.
beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
}
// Register default environment beans.
if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
}
if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {
beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());
}
if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {
beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());
}
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