这篇文章主要介绍“spring-connet的核心方法refresh怎么用”,在日常操作中,相信很多人在spring-connet的核心方法refresh怎么用问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答”spring-connet的核心方法refresh怎么用”的疑惑有所帮助!接下来,请跟着小编一起来学习吧!
refresh是ApplicationContext最核心的方法,如果你搞定了这个方法ApplicationContext的都搞定了。
public void refresh() throws BeansException, IllegalStateException { synchronized (this.startupShutdownMonitor) { prepareRefresh(); ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory(); prepareBeanFactory(beanFactory); try { postProcessBeanFactory(beanFactory); invokeBeanFactoryPostProcessors(beanFactory); registerBeanPostProcessors(beanFactory); initMessageSource(); initApplicationEventMulticaster(); onRefresh(); registerListeners(); finishBeanFactoryInitialization(beanFactory); finishRefresh(); }catch (BeansException ex) { if (logger.isWarnEnabled()) { logger.warn("Exception encountered during context initialization - " + "cancelling refresh attempt: " + ex); } destroyBeans(); cancelRefresh(ex); throw ex; }finally { resetCommonCaches(); } } }
申明与实现AbstractApplicationContext类中
protected void prepareRefresh() { // 启动时间 this.startupDate = System.currentTimeMillis(); // 是否出去关闭状态 this.closed.set(false); // 是否是活跃的,这个状态很重要 this.active.set(true); if (logger.isInfoEnabled()) { logger.info("Refreshing " + this); } initPropertySources(); // 校验配置 getEnvironment().validateRequiredProperties(); // 早期事件 this.earlyApplicationEvents = new LinkedHashSet<ApplicationEvent>(); }
initPropertySources 申明在 AbstractApplicationContext,分别由AbstractRefreshableWebApplicationContext和GenericWebApplicationContext重写,你会方法只是把web的servletContext与servletConfig加入到配置里面了,
protected void initPropertySources() { // For subclasses: do nothing by default. }
GenericWebApplicationContext
protected void initPropertySources() { ConfigurableEnvironment env = getEnvironment(); if (env instanceof ConfigurableWebEnvironment) { ((ConfigurableWebEnvironment) env).initPropertySources(this.servletContext, null); } }
AbstractRefreshableWebApplicationContext
protected void initPropertySources() { ConfigurableEnvironment env = getEnvironment(); if (env instanceof ConfigurableWebEnvironment) { ((ConfigurableWebEnvironment) env).initPropertySources(this.servletContext, this.servletConfig); } }
protected ConfigurableListableBeanFactory obtainFreshBeanFactory() { refreshBeanFactory(); ConfigurableListableBeanFactory beanFactory = getBeanFactory(); if (logger.isDebugEnabled()) { logger.debug("Bean factory for " + getDisplayName() + ": " + beanFactory); } return beanFactory; }
refreshBeanFactory
protected final void refreshBeanFactory() throws BeansException { if (hasBeanFactory()) { // 既然要refresh,那么必须会失败掉所有bean destroyBeans(); // 关闭工厂 closeBeanFactory(); } try { // 创建bean,看过BeanFactory系列文章的同学应该知道,会创建那个对象吧 DefaultListableBeanFactory beanFactory = createBeanFactory(); beanFactory.setSerializationId(getId()); // customizeBeanFactory的内容请看 BeanFactory 系列的章节 customizeBeanFactory(beanFactory); loadBeanDefinitions(beanFactory); synchronized (this.beanFactoryMonitor) { this.beanFactory = beanFactory; } } catch (IOException ex) { throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex); } }
loadBeanDefinitions
创建AnnotatedBeanDefinitionReader 与 ClassPathBeanDefinitionScanner 并加载对应class与 basePackages。注意如果不调用ApplicationContext的方法,是没有class与basePackages的。spring默认扫描路径不在这里
protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) { AnnotatedBeanDefinitionReader reader = getAnnotatedBeanDefinitionReader(beanFactory); ClassPathBeanDefinitionScanner scanner = getClassPathBeanDefinitionScanner(beanFactory); BeanNameGenerator beanNameGenerator = getBeanNameGenerator(); if (beanNameGenerator != null) { reader.setBeanNameGenerator(beanNameGenerator); scanner.setBeanNameGenerator(beanNameGenerator); beanFactory.registerSingleton(AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR, beanNameGenerator); } ScopeMetadataResolver scopeMetadataResolver = getScopeMetadataResolver(); if (scopeMetadataResolver != null) { reader.setScopeMetadataResolver(scopeMetadataResolver); scanner.setScopeMetadataResolver(scopeMetadataResolver); } if (!this.annotatedClasses.isEmpty()) { if (logger.isInfoEnabled()) { logger.info("Registering annotated classes: [" + StringUtils.collectionToCommaDelimitedString(this.annotatedClasses) + "]"); } reader.register(ClassUtils.toClassArray(this.annotatedClasses)); } if (!this.basePackages.isEmpty()) { if (logger.isInfoEnabled()) { logger.info("Scanning base packages: [" + StringUtils.collectionToCommaDelimitedString(this.basePackages) + "]"); } scanner.scan(StringUtils.toStringArray(this.basePackages)); } String[] configLocations = getConfigLocations(); if (configLocations != null) { for (String configLocation : configLocations) { try { Class<?> clazz = getClassLoader().loadClass(configLocation); if (logger.isInfoEnabled()) { logger.info("Successfully resolved class for [" + configLocation + "]"); } reader.register(clazz); } catch (ClassNotFoundException ex) { if (logger.isDebugEnabled()) { logger.debug("Could not load class for config location [" + configLocation + "] - trying package scan. " + ex); } int count = scanner.scan(configLocation); if (logger.isInfoEnabled()) { if (count == 0) { logger.info("No annotated classes found for specified class/package [" + configLocation + "]"); } else { logger.info("Found " + count + " annotated classes in package [" + configLocation + "]"); } } } } } }
在BeanFactory加入一些bean,或者一些规则
*/ protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) { // Tell the internal bean factory to use the context's class loader etc. beanFactory.setBeanClassLoader(getClassLoader()); beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader())); beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment())); // Configure the bean factory with context callbacks. beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this)); // 下面是忽视依赖关系,自动忽视下面对象的依赖, 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()); } }
这是 子类AnnotationConfigReactiveWebServerApplicationContext重写了父类的方法,所以postProcessBeanFactory作用是为子类提供自己行为而设计的。其功能与prepareBeanFactory一模一样。只是面对的对象不一样。
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) { beanFactory.addBeanPostProcessor(new ServletContextAwareProcessor(this.servletContext, this.servletConfig)); beanFactory.ignoreDependencyInterface(ServletContextAware.class); beanFactory.ignoreDependencyInterface(ServletConfigAware.class); WebApplicationContextUtils.registerWebApplicationScopes(beanFactory, this.servletContext); WebApplicationContextUtils.registerEnvironmentBeans(beanFactory, this.servletContext, this.servletConfig); }
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) { PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors()); // Detect a LoadTimeWeaver and prepare for weaving, if found in the meantime // (e.g. through an @Bean method registered by ConfigurationClassPostProcessor) if (beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) { beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory)); beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader())); } }
从 BeanFactory 得到BeanPostProcessors与子接口的实现类。进行排序,然后加到beanFactory的BeanPostProcessor集合中,方面后续操作。功能可以在上面方法执行为了保证单一性,重复执行了一次。
protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) { PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this); }
protected void initMessageSource() { ConfigurableListableBeanFactory beanFactory = getBeanFactory(); 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 + "]"); } } }
protected void initApplicationEventMulticaster() { ConfigurableListableBeanFactory beanFactory = getBeanFactory(); 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 + "]"); } } }
protected void onRefresh() { this.themeSource = UiApplicationContextUtils.initThemeSource(this); }
protected void registerListeners() { // Register statically specified listeners first. 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! 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; this.earlyApplicationEvents = null; if (earlyEventsToProcess != null) { for (ApplicationEvent earlyEvent : earlyEventsToProcess) { getApplicationEventMulticaster().multicastEvent(earlyEvent); } } }
finish beanfactory.因为不同功能的容器,在启动成功之后,需要多factory进行不同的操作。
protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) { // 如果存在conversion 服务,从beanFactory工厂得到并set到beanFctory if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) && beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) { beanFactory.setConversionService( beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)); } if (!beanFactory.hasEmbeddedValueResolver()) { beanFactory.addEmbeddedValueResolver(new StringValueResolver() { @Override public String resolveStringValue(String strVal) { return getEnvironment().resolvePlaceholders(strVal); } }); } // 一个比较鸡肋的功能 String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false); for (String weaverAwareName : weaverAwareNames) { getBean(weaverAwareName); } // Stop using the temporary ClassLoader for type matching. beanFactory.setTempClassLoader(null); // Allow for caching all bean definition metadata, not expecting further changes. beanFactory.freezeConfiguration(); // Instantiate all remaining (non-lazy-init) singletons. beanFactory.preInstantiateSingletons(); }
refresh成功的处理
protected void finishRefresh() { // 初始化ApplicationContext生命周期 initLifecycleProcessor(); // 执行生命周期onRefresh getLifecycleProcessor().onRefresh(); // 执行CntextRefreshed事件 publishEvent(new ContextRefreshedEvent(this)); // Participate in LiveBeansView MBean, if active. LiveBeansView.registerApplicationContext(this); }
prepareRefresh让ApplicationContext做一些准备
obtainFreshBeanFactory由子类解决使用什么BeanFactory,让一些子类自己的处理BeanFactory的事情
prepareBeanFactory是 AbstractApplicationContext规范BeanFactory统一的行为
invokeBeanFactoryPostProcessors 执行BeanPostProcessors
registerBeanPostProcessors 对BeanPostProcessors 排序,并加入beanFactory。接下来就是对ApplicationContext行为初始化与执行
initMessageSource 初始化MessageSource
initApplicationEventMulticaster 初始化ApplicationEventMulticaster
onRefresh 无用
registerListeners 执行事件
finishBeanFactoryInitialization 对beanFactory进行整理工作
finishRefresh
到此,关于“spring-connet的核心方法refresh怎么用”的学习就结束了,希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习,快去试试吧!若想继续学习更多相关知识,请继续关注亿速云网站,小编会继续努力为大家带来更多实用的文章!
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