Spring容器的创建刷新

refresh() 方法

Spring 容器的创建过程主要在 refresh() 方法中

public void refresh() throws BeansException, IllegalStateException {
    synchronized (this.startupShutdownMonitor) {
        // 1、Prepare this context for refreshing.
        prepareRefresh();

        ///2、Tell the subclass to refresh the internal bean factory.
        ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

        ///3、Prepare the bean factory for use in this context.
        prepareBeanFactory(beanFactory);

        try {
            //4、 Allows post-processing of the bean factory in context subclasses.
            postProcessBeanFactory(beanFactory);

            //5、 Invoke factory processors registered as beans in the context.
            invokeBeanFactoryPostProcessors(beanFactory);

            //6、 Register bean processors that intercept bean creation.
            registerBeanPostProcessors(beanFactory);

            //7、 Initialize message source for this context.
            initMessageSource();

            //8、 Initialize event multicaster for this context.
            initApplicationEventMulticaster();

            //9、 Initialize other special beans in specific context subclasses.
            onRefresh();

            //10、 Check for listener beans and register them.
            registerListeners();

            //11、 Instantiate all remaining (non-lazy-init) singletons.
            finishBeanFactoryInitialization(beanFactory);

            //12、 Last step: publish corresponding event.
            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();
        }
    }
}

prepareRefresh()：刷新前准备
- 设置一些状态标记：比如启动时间 startupDate、closed/active 状态
- initPropertySources() 设置 init 属性，此方法交给子类实现
- getEnvironment().validateRequiredProperties()，如果没有 Environment，则 new StandardEnvironment()，然后再调用 validateRequiredProperties() 校验参数
- earlyApplicationEvents = new LinkedHashSet()：保存容器中的一些早期事件
obtainFreshBeanFactory()：获取 BeanFactory
- refreshBeanFactory() 刷新 BeanFactory，在 GenericApplicationContext 的构造方法中 new 一个 DefaultListableBeanFactory，通过 this.beanFactory().setSerialization(getID()); 设置一个唯一的 ID
- getBeanFactory() 返回刚才 GenericApplicationContext 创建的 BeanFactory 对象
prepareBeanFactory(beanFactory)： BeanFactory 的准备工作
- 设置 BeanFactory 的类加载器、表达式解析器(StandardBeanExpressionResolver)、ResourceEditorRegistrar
- 添加 BeanPostProcessor

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Spring容器的创建刷新

refresh() 方法​

refresh() 方法