初探spring applicationContext在web容器中加載過程 首先從WEB.XML入手 ==>web.x

AbstractBeanDefinitionReader.loadBeanDefinitions() 1234567891011121314151617181920212223242526272829303132333435
public int loadBeanDefinitions(String location) throws BeanDefinitionStoreException { ResourceLoader resourceLoader = getResourceLoader(); if (resourceLoader == null) { throw new BeanDefinitionStoreException( "Cannot import bean definitions from location [" + location + "]: no ResourceLoader available"); } if (resourceLoader instanceof ResourcePatternResolver) { // Resource pattern matching available. try {//根據配置文件讀取相應配置 Resource[] resources = ((ResourcePatternResolver) resourceLoader).getResources(location); int loadCount = loadBeanDefinitions(resources); if (logger.isDebugEnabled()) { logger.debug("Loaded " + loadCount + " bean definitions from location pattern [" + location + "]"); } return loadCount; } catch (IOException ex) { throw new BeanDefinitionStoreException( "Could not resolve bean definition resource pattern [" + location + "]", ex); } } else { // Can only load single resources by absolute URL. Resource resource = resourceLoader.getResource(location); int loadCount = loadBeanDefinitions(resource); if (logger.isDebugEnabled()) { logger.debug("Loaded " + loadCount + " bean definitions from location [" + location + "]"); } return loadCount; } }

這個是其中一個ResourceLoader的實現 ==>PathMatchingResourcePatternResolver.getResources(String locationPattern); 1234567891011121314151617181920212223242526272829
public Resource[] getResources(String locationPattern) throws IOException { Assert.notNull(locationPattern, "Location pattern must not be null"); if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) { // a class path resource (multiple resources for same name possible) if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()))) { // a class path resource pattern return findPathMatchingResources(locationPattern); } else { // all class path resources with the given name return findAllClassPathResources(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length())); } } else { // Only look for a pattern after a prefix here // (to not get fooled by a pattern symbol in a strange prefix). int prefixEnd = locationPattern.indexOf(":") + 1; if (getPathMatcher().isPattern(locationPattern.substring(prefixEnd))) { // a file pattern return findPathMatchingResources(locationPattern); } else { // a single resource with the given name return new Resource[] {getResourceLoader().getResource(locationPattern)}; } } }

==>PathMatchingResourcePatternResolver.findPathMatchingResources(String locationPattern); 12345678910111213141516171819202122
protected Resource[] findPathMatchingResources(String locationPattern) throws IOException { String rootDirPath = determineRootDir(locationPattern); String subPattern = locationPattern.substring(rootDirPath.length()); Resource[] rootDirResources = getResources(rootDirPath);//collectionFactory初始化一個set容量爲16 Set result = CollectionFactory.createLinkedSetIfPossible(16); for (int i = 0; i < rootDirResources.length; i++) { Resource rootDirResource = rootDirResources[i]; if (isJarResource(rootDirResource)) { result.addAll(doFindPathMatchingJarResources(rootDirResource, subPattern)); } else { result.addAll(doFindPathMatchingFileResources(rootDirResource, subPattern)); } } if (logger.isDebugEnabled()) { logger.debug("Resolved location pattern [" + locationPattern + "] to resources " + result); } return (Resource[]) result.toArray(new Resource[result.size()]); }

前面說到有一個刷新WebApplicationContext的操作,但是XmlWebApplicationContext 並沒有實現refresh方法,而方法的實現寫在 AbstractRefreshableWebApplicationContext 中 ==>AbstractRefreshableWebApplicationContext.refresh(); 1234567
public void refresh() throws BeansException { if (ObjectUtils.isEmpty(getConfigLocations())) { //設置configLocations爲默認的getDefaultConfigLocations() setConfigLocations(getDefaultConfigLocations()); } super.refresh(); }

==>AbstractApplicationContext.refresh(); 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778
public void refresh() throws BeansException, IllegalStateException { synchronized (this.startupShutdownMonitor) { this.startupTime = System.currentTimeMillis(); synchronized (this.activeMonitor) { this.active = true; } // Tell subclass to refresh the internal bean factory. refreshBeanFactory(); ConfigurableListableBeanFactory beanFactory = getBeanFactory(); // Tell the internal bean factory to use the context's class loader. beanFactory.setBeanClassLoader(getClassLoader()); // Populate the bean factory with context-specific resource editors. beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this)); // Configure the bean factory with context semantics. beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this)); beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class); beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class); beanFactory.ignoreDependencyInterface(MessageSourceAware.class); beanFactory.ignoreDependencyInterface(ApplicationContextAware.class); // Allows post-processing of the bean factory in context subclasses. postProcessBeanFactory(beanFactory); // Invoke factory processors registered with the context instance. for (Iterator it = getBeanFactoryPostProcessors().iterator(); it.hasNext();) { BeanFactoryPostProcessor factoryProcessor = (BeanFactoryPostProcessor) it.next(); factoryProcessor.postProcessBeanFactory(beanFactory); } if (logger.isInfoEnabled()) { if (getBeanDefinitionCount() == 0) { logger.info("No beans defined in application context [" + getDisplayName() + "]"); } else { logger.info(getBeanDefinitionCount() + " beans defined in application context [" + getDisplayName() + "]"); } } try { // Invoke factory processors registered as beans in the context. invokeBeanFactoryPostProcessors(); // Register bean processors that intercept bean creation. registerBeanPostProcessors(); // Initialize message source for this context. initMessageSource(); // Initialize event multicaster for this context. initApplicationEventMulticaster(); // Initialize other special beans in specific context subclasses. onRefresh(); // Check for listener beans and register them. registerListeners(); // Instantiate singletons this late to allow them to access the message source. beanFactory.preInstantiateSingletons(); // Last step: publish corresponding event. publishEvent(new ContextRefreshedEvent(this)); } catch (BeansException ex) { // Destroy already created singletons to avoid dangling resources. beanFactory.destroySingletons(); throw ex; } } }