参考源

《Spring源码深度解析(第2版)》

版本

本文章基于 Spring 5.3.15

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Spring IOC 的核心是 AbstractApplicationContext 的 refresh 方法。

其中一共有 13 个主要方法，这里分析第 3 个：prepareBeanFactory。

1 AbstractApplicationContext

1-1 对 BeanFactory 进行功能填充

prepareBeanFactory(beanFactory)

protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {   // 设置 beanFactory 的 classLoader 为当前 context 的 classLoader   beanFactory.setBeanClassLoader(getClassLoader());   if (!shouldIgnoreSpel) {      /**       * 设置bean Factory 的表达式语言处理桥， Spring3 增加了表达式语言的支持       * 默认可以使用 #{bean.xxx} 的形式来调用相关属性值       */      beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));   }   // 为 beanFactory 增加了一个默认的 propertyEditor，这个主要是对 bean 的属性等设置管理的一个工具   beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));   // 添加 Bean 增强器   beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));   // 设置忽略自动装配的接口   beanFactory.ignoreDependencyInterface(EnvironmentAware.class);   beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);   beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);   beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);   beanFactory.ignoreDependencyInterface(MessageSourceAware.class);   beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);   beanFactory.ignoreDependencyInterface(ApplicationStartupAware.class);   // 设置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);   // 添加 Bean 增强器   beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));   // 增加对 AspectJ 的支持   if (!NativeDetector.inNativeImage() && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {      beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));      // 为类型匹配设置临时类加载器      beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));   }   // 添加默认的系统环境 bean   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());   }   if (!beanFactory.containsLocalBean(APPLICATION_STARTUP_BEAN_NAME)) {      beanFactory.registerSingleton(APPLICATION_STARTUP_BEAN_NAME, getApplicationStartup());   }}