Hi，大家好，我是编程小6，很荣幸遇见你，我把这些年在开发过程中遇到的问题或想法写出来，今天说一说
spring配置文件中怎么加载属性文件?_spring加载配置文件过程,希望能够帮助你!!!。

流程图如下:

1、创建工厂

obtainFreshBeanFactory():创建容器对象 ,加载配置文件到当前工厂代；

protected ConfigurableListableBeanFactory obtainFreshBeanFactory() { // 初始化BeanFactory,并进行XML文件读取，并将得到的BeanFactory记录在当前实体的属性中 refreshBeanFactory(); // 返回当前实体的beanFactory属性 return getBeanFactory(); }

2、初始化BeanFactory

@Override protected final void refreshBeanFactory() throws BeansException { // 如果存在beanFactory，则销毁beanFactory if (hasBeanFactory()) { destroyBeans(); closeBeanFactory(); } try { // 创建DefaultListableBeanFactory对象 DefaultListableBeanFactory beanFactory = createBeanFactory(); // 为了序列化指定id，可以从id反序列化到beanFactory对象 beanFactory.setSerializationId(getId()); // 定制beanFactory，设置相关属性，包括是否允许覆盖同名称的不同定义的对象以及循环依赖 customizeBeanFactory(beanFactory); // 初始化documentReader,并进行XML文件读取及解析,默认命名空间的解析，自定义标签的解析 loadBeanDefinitions(beanFactory); this.beanFactory = beanFactory; } catch (IOException ex) { throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex); } }

3、初始化documentReader,并进行XML文件读取及解析,默认命名空间的解析，自定义标签的解析：loadBeanDefinitions(DefaultListableBeanFactory beanFactory)

@Override protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) throws BeansException, IOException { // Create a new XmlBeanDefinitionReader for the given BeanFactory. // 创建一个xml的beanDefinitionReader，并通过回调设置到beanFactory中 XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory); // Configure the bean definition reader with this context's // resource loading environment. // 给reader对象设置环境对象 beanDefinitionReader.setEnvironment(this.getEnvironment()); beanDefinitionReader.setResourceLoader(this); beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this)); // Allow a subclass to provide custom initialization of the reader, // then proceed with actually loading the bean definitions. // 初始化beanDefinitionReader对象，此处设置配置文件是否要进行验证 initBeanDefinitionReader(beanDefinitionReader); // 开始完成beanDefinition的加载 loadBeanDefinitions(beanDefinitionReader); }

4、开始beanDefinition的加载：loadBeanDefinitions(XmlBeanDefinitionReader reader)

protected void loadBeanDefinitions(XmlBeanDefinitionReader reader) throws BeansException, IOException { // 以Resource的方式获得配置文件的资源位置 Resource[] configResources = getConfigResources(); if (configResources != null) { reader.loadBeanDefinitions(configResources); } // 以String的形式获得配置文件的位置 String[] configLocations = getConfigLocations(); if (configLocations != null) { reader.loadBeanDefinitions(configLocations); } }

5、以Resource的方式获得配置文件的资源位置：loadBeanDefinitions(Resource... resources)//以下是debug的流程

以下debug流程：

@Override public int loadBeanDefinitions(Resource... resources) throws BeanDefinitionStoreException { Assert.notNull(resources, "Resource array must not be null"); int count = 0; for (Resource resource : resources) { //加载resource count += loadBeanDefinitions(resource); } return count; } @Override public int loadBeanDefinitions(Resource resource) throws BeanDefinitionStoreException { return loadBeanDefinitions(new EncodedResource(resource)); } public int loadBeanDefinitions(EncodedResource encodedResource) throws BeanDefinitionStoreException { Assert.notNull(encodedResource, "EncodedResource must not be null"); if (logger.isTraceEnabled()) { logger.trace("Loading XML bean definitions from " + encodedResource); } // 通过属性来记录已经加载的资源 Set<EncodedResource> currentResources = this.resourcesCurrentlyBeingLoaded.get(); if (!currentResources.add(encodedResource)) { throw new BeanDefinitionStoreException( "Detected cyclic loading of " + encodedResource + " - check your import definitions!"); } // 从encodedResource中获取已经封装的Resource对象并再次从Resource中获取其中的inputStream try (InputStream inputStream = encodedResource.getResource().getInputStream()) { InputSource inputSource = new InputSource(inputStream); if (encodedResource.getEncoding() != null) { inputSource.setEncoding(encodedResource.getEncoding()); } // 逻辑处理的核心步骤 return doLoadBeanDefinitions(inputSource, encodedResource.getResource()); } catch (IOException ex) { throw new BeanDefinitionStoreException( "IOException parsing XML document from " + encodedResource.getResource(), ex); } finally { currentResources.remove(encodedResource); if (currentResources.isEmpty()) { this.resourcesCurrentlyBeingLoaded.remove(); } } }

protected int doLoadBeanDefinitions(InputSource inputSource, Resource resource) throws BeanDefinitionStoreException { try { // 此处获取xml文件的document对象，这个解析过程是由documentLoader完成的,从String[] -string-Resource[]- resource,最终开始将resource读取成一个document文档，根据文档的节点信息封装成一个个的BeanDefinition对象 Document doc = doLoadDocument(inputSource, resource); int count = registerBeanDefinitions(doc, resource); if (logger.isDebugEnabled()) { logger.debug("Loaded " + count + " bean definitions from " + resource); } return count; } catch (BeanDefinitionStoreException ex) { throw ex; } catch (SAXParseException ex) { throw new XmlBeanDefinitionStoreException(resource.getDescription(), "Line " + ex.getLineNumber() + " in XML document from " + resource + " is invalid", ex); } catch (SAXException ex) { throw new XmlBeanDefinitionStoreException(resource.getDescription(), "XML document from " + resource + " is invalid", ex); } catch (ParserConfigurationException ex) { throw new BeanDefinitionStoreException(resource.getDescription(), "Parser configuration exception parsing XML from " + resource, ex); } catch (IOException ex) { throw new BeanDefinitionStoreException(resource.getDescription(), "IOException parsing XML document from " + resource, ex); } catch (Throwable ex) { throw new BeanDefinitionStoreException(resource.getDescription(), "Unexpected exception parsing XML document from " + resource, ex); } }

protected Document doLoadDocument(InputSource inputSource, Resource resource) throws Exception { return this.documentLoader.loadDocument(inputSource, getEntityResolver(), this.errorHandler, getValidationModeForResource(resource), isNamespaceAware()); } public int registerBeanDefinitions(Document doc, Resource resource) throws BeanDefinitionStoreException { // 对xml的beanDefinition进行解析 BeanDefinitionDocumentReader documentReader = createBeanDefinitionDocumentReader(); int countBefore = getRegistry().getBeanDefinitionCount(); // 完成具体的解析过程 documentReader.registerBeanDefinitions(doc, createReaderContext(resource)); return getRegistry().getBeanDefinitionCount() - countBefore; }

protected void doRegisterBeanDefinitions(Element root) { // Any nested <beans> elements will cause recursion in this method. In // order to propagate and preserve <beans> default-* attributes correctly, // keep track of the current (parent) delegate, which may be null. Create // the new (child) delegate with a reference to the parent for fallback purposes, // then ultimately reset this.delegate back to its original (parent) reference. // this behavior emulates a stack of delegates without actually necessitating one. BeanDefinitionParserDelegate parent = this.delegate; this.delegate = createDelegate(getReaderContext(), root, parent); if (this.delegate.isDefaultNamespace(root)) { String profileSpec = root.getAttribute(PROFILE_ATTRIBUTE); if (StringUtils.hasText(profileSpec)) { String[] specifiedProfiles = StringUtils.tokenizeToStringArray( profileSpec, BeanDefinitionParserDelegate.MULTI_VALUE_ATTRIBUTE_DELIMITERS); // We cannot use Profiles.of(...) since profile expressions are not supported // in XML config. See SPR-12458 for details. if (!getReaderContext().getEnvironment().acceptsProfiles(specifiedProfiles)) { if (logger.isDebugEnabled()) { logger.debug("Skipped XML bean definition file due to specified profiles [" + profileSpec + "] not matching: " + getReaderContext().getResource()); } return; } } } preProcessXml(root); //解析标签 parseBeanDefinitions(root, this.delegate); postProcessXml(root); this.delegate = parent; }

protected void parseBeanDefinitions(Element root, BeanDefinitionParserDelegate delegate) { if (delegate.isDefaultNamespace(root)) { NodeList nl = root.getChildNodes(); for (int i = 0; i < nl.getLength(); i++) { Node node = nl.item(i); if (node instanceof Element) { Element ele = (Element) node; if (delegate.isDefaultNamespace(ele)) { //解析默认标签 parseDefaultElement(ele, delegate); } else { //解析自定义标签 delegate.parseCustomElement(ele); } } } } else { delegate.parseCustomElement(root); } }

6、以String的形式获得配置文件的位置：loadBeanDefinitions(String... locations)

@Override public int loadBeanDefinitions(String... locations) throws BeanDefinitionStoreException { Assert.notNull(locations, "Location array must not be null"); int count = 0; for (String location : locations) { count += loadBeanDefinitions(location); } return count; }

public int loadBeanDefinitions(String location, @Nullable Set<Resource> actualResources) throws BeanDefinitionStoreException { //此处获取resourceLoader对象 ResourceLoader resourceLoader = getResourceLoader(); if (resourceLoader == null) { throw new BeanDefinitionStoreException( "Cannot load bean definitions from location [" + location + "]: no ResourceLoader available"); } if (resourceLoader instanceof ResourcePatternResolver) { // Resource pattern matching available. try { // 调用DefaultResourceLoader的getResource完成具体的Resource定位 Resource[] resources = ((ResourcePatternResolver) resourceLoader).getResources(location); int count = loadBeanDefinitions(resources); if (actualResources != null) { Collections.addAll(actualResources, resources); } if (logger.isTraceEnabled()) { logger.trace("Loaded " + count + " bean definitions from location pattern [" + location + "]"); } return count; } 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 count = loadBeanDefinitions(resource); if (actualResources != null) { actualResources.add(resource); } if (logger.isTraceEnabled()) { logger.trace("Loaded " + count + " bean definitions from location [" + location + "]"); } return count; } }

全文以debug的角度追踪源码，整理出大部分核心代码，还有些细节之处还需要自己去debug加深理解。

今天的分享到此就结束了，感谢您的阅读，如果确实帮到您，您可以动动手指转发给其他人。