spring加载流程refresh之prepareBeanFactory(beanFactory)
转载自
https://blog.csdn.net/yu_kang/article/details/88078220
1、以下就是整个prepareBeanFactory方法的内容
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { // Tell the internal bean factory to use the context's class loader etc. /** * 设置上下文类加载器 */ beanFactory.setBeanClassLoader(getClassLoader()); /** * 添加bean表达式解释器,为了能够让我们的beanFactory去解析bean表达式 * 模板默认以前缀“#{”开头,以后缀“}”结尾 * 可以修改默认额前缀后缀 * 通过beanFactory.getBeanExpressionResolver()获得BeanExpressionResolver * 然后resolver.setExpressionPrefix("%{");resolver.setExpressionSuffix("}"); * * 那么什么时候用到这个解析器? * 就是在Bean进行初始化后会有属性填充的一步,方法如下: * protected void populateBean(String beanName, RootBeanDefinition mbd, BeanWrapper bw) { * //属性填充 * applyPropertyValues(beanName, mbd, bw, pvs); * } * 最终会通过AbstractBeanFactory中的evaluateBeanDefinitionString方法进行解析 * 然后这时候就进到StandardBeanExpressionResolver中的evaluate方法中进行解析了 */ beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader())); /** * spring内部的属性编辑器 * 添加PropertyEditor属性编辑器(可以将我们的property动态设置为bean里面对应的属性类型) * 比如:property赋值的是路径名(classpath/spring.xml),而对应bean属性设置的是Resource,则有spring的ResourceEditor完成转换 * springframework-bean下的propertyEditors包下有很多spring自带的属性编辑器 * 其中刚才提到的ResourceEditor在springframework-core下的io包里面 * * 可以自定义属性编辑器,通过实现PropertyEditorSupport接口,spring中自带的属性编辑器也是这么做的 * 使用ApplicationContext,只需要在配置文件中通过CustomEditorConfigurer注册即可。 * CustomEditorConfigurer实现了BeanFactoryPostProcessor接口,因而是一个Bean工厂后置处理器 * 在Spring容器中加载配置文件并生成BeanDefinition后会被执行。CustomEditorConfigurer在容器启动时有机会注册自定义的属性编辑器 */ beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment())); // Configure the bean factory with context callbacks. /** * 添加一个BPP * ApplicationContextAwareProcessor:能够在bean中获得各种*Aware */ beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this)); /** * 跳过以下6个属性的自动注入 * 因为在ApplicationContextAwareProcessor中已经完成了手动注入 */ 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 interface not registered as resolvable type in a plain factory. // MessageSource registered (and found for autowiring) as a bean. /** * 注册几个自动装配相关的类和实例 * 在应用代码就可以通过类型自动装配把工厂实例和ApplicationContext实例设置到自定义bean的属性中 * * 例如:这几个属性都会被自动设置,虽然没有在显示的在bean定义xml中注入它们 * private BeanFactory beanFactory; * private ResourceLoader resourceLoader; * private ApplicationEventPublisher appEventPublisher; * private ApplicationContext appContext; */ beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory); beanFactory.registerResolvableDependency(ResourceLoader.class, this); beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this); beanFactory.registerResolvableDependency(ApplicationContext.class, this); // Register early post-processor for detecting inner beans as ApplicationListeners. /** * 添加一个BPP,处理时间监听器 */ beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this)); // Detect a LoadTimeWeaver and prepare for weaving, if found. /** * 当容器检查到定义了名称为loadTimeWeaver的bean时 * 会注册一个LoadTimeWeaverAwareProcessor到容器中 * * 这个BPP用来处理LoadTimeWeaverAware接口的 * 把LTW实例设置到实现了LoadTimeWeaverAware接口的bean中 */ 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. /** * 就是一些系统配置和系统环境信息 * 如果发现没有这些bean则spring自己注册 */ 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()); } } }