1、refresh()
public AnnotationConfigApplicationContext(Class<?>... annotatedClasses) { this(); register(annotatedClasses); refresh(); } public void refresh() throws BeansException, IllegalStateException { synchronized (this.startupShutdownMonitor) { // Prepare this context for refreshing.
//准备工作：设置启动时间、是否激活标识位 初始化早期事件 prepareRefresh(); // 获取DefaultListableBeanFactory，创建容器是在上面this()方法中实现的，如果是xml配置的，会在这里解析bean定义 ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory(); // 准备bean工厂，注册了部分类 prepareBeanFactory(beanFactory); try { // 待子类实现 postProcessBeanFactory(beanFactory); // 注册bean工厂后置处理器，并解析java代码配置bean定义，前面已经分析过，见https://www.cnblogs.com/pjfmeng/p/13948535.html invokeBeanFactoryPostProcessors(beanFactory); // 注册bean后置处理器，并不会执行后置处理器，在后面实例化的时候执行 registerBeanPostProcessors(beanFactory); // 国际化支持 initMessageSource(); // 初始化事件监听多路广播器 initApplicationEventMulticaster(); // 待子类实现，springBoot在这里实现创建内置的tomact容器 onRefresh(); // 注册监听器 registerListeners(); // 单例实例化，前面已经分析过，见 https://www.cnblogs.com/pjfmeng/p/13957917.html finishBeanFactoryInitialization(beanFactory); // 广播事件，ApplicationContext初始化完成，springColud有实现该方法，待后续分析 finishRefresh(); } catch (BeansException ex) { if (logger.isWarnEnabled()) { logger.warn("Exception encountered during context initialization - " + "cancelling refresh attempt: " + ex); } // 刷新失败后的处理，主要是将一些保存环境信息的集合做清理 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(); } } }
1.1 prepareRefresh（）
protected void prepareRefresh() { this.startupDate = System.currentTimeMillis(); this.closed.set(false); //设置激活 this.active.set(true); if (logger.isInfoEnabled()) { logger.info("Refreshing " + this); } // Initialize any placeholder property sources in the context environment //空方法，可以自己实现做一些环境变量的设置，比如说设置某些变量必填 initPropertySources(); // 校验环境变量的缺失 getEnvironment().validateRequiredProperties(); // Allow for the collection of early ApplicationEvents, // to be published once the multicaster is available... //新建一个list保存早期事件，因为这时候还没有注册监听器，不能发布事件 this.earlyApplicationEvents = new LinkedHashSet<ApplicationEvent>(); }
1.2、obtainFreshBeanFactory
protected ConfigurableListableBeanFactory obtainFreshBeanFactory() { //刷新bean工厂，xml配置的bean定义会在这里被加载进来存储在DefaultListableBeanFactory的beanDefinitionMap里面 //java配置的@bean,或者componentScan扫描的组件是在后面通过bean工厂后处理器倒进来的，也就是上面的第五步 refreshBeanFactory(); ConfigurableListableBeanFactory beanFactory = getBeanFactory(); if (logger.isDebugEnabled()) { logger.debug("Bean factory for " + getDisplayName() + ": " + beanFactory); } return beanFactory; }
//AbstractRefreshableApplicationContext#refreshBeanFactory protected final void refreshBeanFactory() throws BeansException { if (hasBeanFactory()) { destroyBeans(); closeBeanFactory(); } try { DefaultListableBeanFactory beanFactory = createBeanFactory(); beanFactory.setSerializationId(getId()); customizeBeanFactory(beanFactory); //注册xml配置的bean定义 loadBeanDefinitions(beanFactory); synchronized (this.beanFactoryMonitor) { this.beanFactory = beanFactory; } } catch (IOException ex) { throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex); } }
1.3 prepareBeanFactory
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { // Tell the internal bean factory to use the context's class loader etc.
//给beanFactory设置类加载器 beanFactory.setBeanClassLoader(getClassLoader());
//设置EL表达式解析器 beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
//添加属性 beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment())); // Configure the bean factory with context callbacks.
//设置ApplicationContextAwareProcessor，打开这个类的postProcessBeforeInitialization（）方法，会发现用于在bean初始化之前，前置调用
EnvironmentAware EmbeddedValueResolverAware ApplicationEventPublisherAware MessageSourceAware ApplicationContextAware，注入bean中
beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
//上面会自动注入，所以这里要把这些接口忽略掉 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. 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. beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(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()); } }
1.4 、postProcessBeanFactory
空方法，待子类实现
1.5、invokeBeanFactoryPostProcessors
注册bean工厂后置处理器，并解析java代码配置bean定义，前面已经分析过，见 spring源码解析bean定义。
1.6、registerBeanPostProcessors
protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) { PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this); } public static void registerBeanPostProcessors( ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) { //理解了上一步的invokeBeanFactoryPostProcessors， 那这里就理解起来就相当容易了， //唯一有区别的是由于这里是注册BeanPostProcessor，而BeanPostProcessor是在每个bean实例化前后调用的， //所以这里只是单独的注册到beanFactory，并没有逐个执行 //先执行PriorityOrdered修饰的，然后执行Ordered，最后执行普通的 String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false); // Register BeanPostProcessorChecker that logs an info message when // a bean is created during BeanPostProcessor instantiation, i.e. when // a bean is not eligible for getting processed by all BeanPostProcessors. int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length; beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount)); // Separate between BeanPostProcessors that implement PriorityOrdered, // Ordered, and the rest. //开始根据beanName遍历BeanPostProcessor，并按照PriorityOrdered、Ordered以及其他进行分类 List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>(); List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>(); List<String> orderedPostProcessorNames = new ArrayList<String>(); List<String> nonOrderedPostProcessorNames = new ArrayList<String>(); for (String ppName : postProcessorNames) { if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) { BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class); priorityOrderedPostProcessors.add(pp); if (pp instanceof MergedBeanDefinitionPostProcessor) { internalPostProcessors.add(pp); } } else if (beanFactory.isTypeMatch(ppName, Ordered.class)) { orderedPostProcessorNames.add(ppName); } else { nonOrderedPostProcessorNames.add(ppName); } } // First, register the BeanPostProcessors that implement PriorityOrdered. //排序并注册实现了PriorityOrdered的BeanPostProcessor sortPostProcessors(priorityOrderedPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors); // Next, register the BeanPostProcessors that implement Ordered. //排序并注册实现了Ordered的BeanPostProcessor List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>(); for (String ppName : orderedPostProcessorNames) { BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class); orderedPostProcessors.add(pp); if (pp instanceof MergedBeanDefinitionPostProcessor) { internalPostProcessors.add(pp); } } sortPostProcessors(orderedPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, orderedPostProcessors); // Now, register all regular BeanPostProcessors. //排序并注册了剩余的BeanPostProcessor List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>(); for (String ppName : nonOrderedPostProcessorNames) { BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class); nonOrderedPostProcessors.add(pp); if (pp instanceof MergedBeanDefinitionPostProcessor) { internalPostProcessors.add(pp); } } registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors); // Finally, re-register all internal BeanPostProcessors. //4、排序并注册了实现了MergedBeanDefinitionPostProcessor的BeanPostProcessor sortPostProcessors(internalPostProcessors, beanFactory); registerBeanPostProcessors(beanFactory, internalPostProcessors); // Re-register post-processor for detecting inner beans as ApplicationListeners, // moving it to the end of the processor chain (for picking up proxies etc). beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext)); }
1.7 initMessageSource
国际化支持，如果需要用到国际化可以从bean容器中获取messageSource,然后调用他的getMessage方法获取国际化支持
protected void initMessageSource() { ConfigurableListableBeanFactory beanFactory = getBeanFactory(); //查看bean容器中是否有定义messageSource，若没有则会实例化一个DelegatingMessageSource并注册到beanFactory if (beanFactory.containsLocalBean(MESSAGE_SOURCE_BEAN_NAME)) { this.messageSource = beanFactory.getBean(MESSAGE_SOURCE_BEAN_NAME, MessageSource.class); // Make MessageSource aware of parent MessageSource. if (this.parent != null && this.messageSource instanceof HierarchicalMessageSource) { HierarchicalMessageSource hms = (HierarchicalMessageSource) this.messageSource; if (hms.getParentMessageSource() == null) { // Only set parent context as parent MessageSource if no parent MessageSource // registered already. hms.setParentMessageSource(getInternalParentMessageSource()); } } if (logger.isDebugEnabled()) { logger.debug("Using MessageSource [" + this.messageSource + "]"); } } else { // Use empty MessageSource to be able to accept getMessage calls. DelegatingMessageSource dms = new DelegatingMessageSource(); dms.setParentMessageSource(getInternalParentMessageSource()); this.messageSource = dms; beanFactory.registerSingleton(MESSAGE_SOURCE_BEAN_NAME, this.messageSource); if (logger.isDebugEnabled()) { logger.debug("Unable to locate MessageSource with name '" + MESSAGE_SOURCE_BEAN_NAME + "': using default [" + this.messageSource + "]"); } } }
1.8、initApplicationEventMulticaster
protected void initApplicationEventMulticaster() { ConfigurableListableBeanFactory beanFactory = getBeanFactory(); //从beanFactory中查找applicationEventMulticaster，
//若没有则会初始化一个SimpleApplicationEventMulticaster并注册到beanFactory
//我们也可以实现多播器，可以设置异步线程等等
if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) { this.applicationEventMulticaster = beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class); if (logger.isDebugEnabled()) { logger.debug("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]"); } } else { this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory); beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster); if (logger.isDebugEnabled()) { logger.debug("Unable to locate ApplicationEventMulticaster with name '" + APPLICATION_EVENT_MULTICASTER_BEAN_NAME + "': using default [" + this.applicationEventMulticaster + "]"); } } }
1.9、onRefresh()
空方法，给子类扩展，springBoot的内嵌tomact就是在这一部创建的，待后续分析
1.10、registerListeners
protected void registerListeners() { // Register statically specified listeners first. //首先将所有已添加的监听器绑定到事件广播器中 for (ApplicationListener<?> listener : getApplicationListeners()) { getApplicationEventMulticaster().addApplicationListener(listener); } // Do not initialize FactoryBeans here: We need to leave all regular beans // uninitialized to let post-processors apply to them! //然后再从beanFactory中获取所有ApplicationListener，将beanName绑定到事件广播器中 String[] listenerBeanNames = getBeanNamesForType(ApplicationListener.class, true, false); for (String listenerBeanName : listenerBeanNames) { getApplicationEventMulticaster().addApplicationListenerBean(listenerBeanName); } // Publish early application events now that we finally have a multicaster... Set<ApplicationEvent> earlyEventsToProcess = this.earlyApplicationEvents; //在这里发布早期事件，也就是上面说的earlyApplicationEvents this.earlyApplicationEvents = null; if (earlyEventsToProcess != null) { for (ApplicationEvent earlyEvent : earlyEventsToProcess) { getApplicationEventMulticaster().multicastEvent(earlyEvent); } } }
1.11、finishBeanFactoryInitialization
实例化单例，前面分析过，见spring源码解析二( getBean())
1.12、finishRefresh
protected void finishRefresh() { // Initialize lifecycle processor for this context. initLifecycleProcessor(); // Propagate refresh to lifecycle processor first. getLifecycleProcessor().onRefresh(); // Publish the final event. publishEvent(new ContextRefreshedEvent(this)); // Participate in LiveBeansView MBean, if active. LiveBeansView.registerApplicationContext(this); }