网站建设叁金手指花总7,网站设计就业怎么样,网络营销类型有哪些,南宁seo网络推广文章目录 一、Spring生命周期核心底层源码剖析—扫描1.1、Spring底层扫描机制doScan方法源码剖析 一、Spring生命周期核心底层源码剖析—扫描
1.1、Spring底层扫描机制doScan方法源码剖析
其源代码如下#xff1a;
protected SetBeanDefinitionHolder doScan(Strin… 文章目录 一、Spring生命周期核心底层源码剖析—扫描1.1、Spring底层扫描机制doScan方法源码剖析 一、Spring生命周期核心底层源码剖析—扫描
1.1、Spring底层扫描机制doScan方法源码剖析
其源代码如下
protected SetBeanDefinitionHolder doScan(String... basePackages) {Assert.notEmpty(basePackages, At least one base package must be specified);SetBeanDefinitionHolder beanDefinitions new LinkedHashSet();for (String basePackage : basePackages) {SetBeanDefinition candidates findCandidateComponents(basePackage);//遍历其获取到的BeanDefinition对象for (BeanDefinition candidate : candidates) {//为其BeanDefinition对象进行属性赋值例如scopebeanName等ScopeMetadata scopeMetadata this.scopeMetadataResolver.resolveScopeMetadata(candidate);candidate.setScope(scopeMetadata.getScopeName());String beanName this.beanNameGenerator.generateBeanName(candidate, this.registry);if (candidate instanceof AbstractBeanDefinition) {postProcessBeanDefinition((AbstractBeanDefinition) candidate, beanName);}if (candidate instanceof AnnotatedBeanDefinition) {AnnotationConfigUtils.processCommonDefinitionAnnotations((AnnotatedBeanDefinition) candidate);}//判断当前的bean是否已经在Spring容器中存在存在需封装为BeanDefinitionHolder对象if (checkCandidate(beanName, candidate)) {BeanDefinitionHolder definitionHolder new BeanDefinitionHolder(candidate, beanName);definitionHolder AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);beanDefinitions.add(definitionHolder);registerBeanDefinition(definitionHolder, this.registry);}}}return beanDefinitions;}1、其主要是通过传入的包路径进行资源加载加载时方法为上诉代码的for循环下的第一行代码的findCandidateComponents()方法可以详细看此方法是如何加载资源的其方法代码如下具体说明以及解析过程可参考注释
public SetBeanDefinition findCandidateComponents(String basePackage) {//此处主要是判断项目是否配置了相关的bean文件若有就不需要再逐个类进行扫描判断是否为Beanif (this.componentsIndex ! null indexSupportsIncludeFilters()) {return addCandidateComponentsFromIndex(this.componentsIndex, basePackage);}//大部分的业务都会走如下方法else {return scanCandidateComponents(basePackage);}}//scanCandidateComponents方法具体实现为
private SetBeanDefinition scanCandidateComponents(String basePackage) {SetBeanDefinition candidates new LinkedHashSet();try {//1、资源路径组装解析String packageSearchPath ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX resolveBasePackage(basePackage) / this.resourcePattern;//2、利用类元数据读取器读取器路径下包含的资源数据Resource[] resources getResourcePatternResolver().getResources(packageSearchPath);boolean traceEnabled logger.isTraceEnabled();boolean debugEnabled logger.isDebugEnabled();//3、遍历类元数据读取器获取到的资源数据class资源文件数据for (Resource resource : resources) {if (traceEnabled) {logger.trace(Scanning resource);}try {//4、获取当前类元数据(calss)具体资源信息MetadataReader metadataReader getMetadataReaderFactory().getMetadataReader(resource);//5、判断当前的类class上包含的是否包含排除注解excludeFilters以及非排除注解includeFilters以及是否包含相关的条件注解Conditionalif (isCandidateComponent(metadataReader)) {//6、创建一个BeanDefinition对象用于封装其类特征信息例如beanClass、scope、lazyInit等属性ScannedGenericBeanDefinition sbd new ScannedGenericBeanDefinition(metadataReader);//7、将类资源数据加入到BeanDefinition中sbd.setSource(resource);//8、判断当前的类资源是否是独立的例如是否是内部类等除此歪需要判断其是否为接口或者抽象类如果是抽象类那类中必须有被Lookup注解的方法否则不会被当做beanif (isCandidateComponent(sbd)) {if (debugEnabled) {logger.debug(Identified candidate component class: resource);}//9、将封装好的BeanDefinition对象加入到返回的集合Set中candidates.add(sbd);}else {if (debugEnabled) {logger.debug(Ignored because not a concrete top-level class: resource);}}}else {if (traceEnabled) {logger.trace(Ignored because not matching any filter: resource);}}}catch (FileNotFoundException ex) {if (traceEnabled) {logger.trace(Ignored non-readable resource : ex.getMessage());}}catch (Throwable ex) {throw new BeanDefinitionStoreException(Failed to read candidate component class: resource, ex);}}}catch (IOException ex) {throw new BeanDefinitionStoreException(I/O failure during classpath scanning, ex);}return candidates;}
