Spring核心IOC源码解读(二)为BeanFactory准备数据

  在SpringIOC获取到BeanFactory之后,需要为BeanFactory初始化一些属性,因为此时BeanFactory中只有最基本的BeanDefinition信息,还没有解析BeanDefinition相关的工具,所以在这一步中Spring将SpEL解析器、属性编辑器、Bean后置处理器、系统基本属性等信息依赖到BeanFactory中去。 AbstractApplicationContext.prepareBeanFactory() 方法块代码👇

    protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        //(1)设置类加载器,用于类加载
        beanFactory.setBeanClassLoader(getClassLoader());
        //(2)设置SpEL解析器,用于解析Spring EL表达式,解析类似 #{user.userName}的属性
        beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
        //(3)添加属性编辑器
        beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));

        //(4)添加Bean后置处理器
        beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
        //(5)添加要忽略自动注入的接口
        beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
        ...
        
        //(6)注册已经可解析的依赖,主要就是BeanFactory
        beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
        beanFactory.registerResolvableDependency(ResourceLoader.class, this);
        beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
        beanFactory.registerResolvableDependency(ApplicationContext.class, this);
        //(7)添加Bean后置处理器
        beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));
        //(8)注册系统环境属性信息到IOC容器中
        if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
            beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
        }
        ...
    }

 

posted on 2020-09-25 11:13  lyjlyjlyj  阅读(123)  评论(0编辑  收藏  举报

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