处理到这一步，仅仅是获取到了所有的@ComponentScan注解，接下来还需要解析注解里面配置的包路径
// ConfigurationClassParser.class 284行 for (AnnotationAttributes componentScan : componentScans) { // 解析当前注解配置的包路径下的类 // The config class is annotated with @ComponentScan -> perform the scan immediately Set<BeanDefinitionHolder> scannedBeanDefinitions = this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName()); // 检查返回的BeanDefinition里面是否有其他的配置类，如果需要的话会递归进行解析 // Check the set of scanned definitions for any further config classes and parse recursively if needed for (BeanDefinitionHolder holder : scannedBeanDefinitions) { BeanDefinition bdCand = holder.getBeanDefinition().getOriginatingBeanDefinition(); if (bdCand == null) { bdCand = holder.getBeanDefinition(); } // 若是配置类，执行配置类的解析操作 if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) { parse(bdCand.getBeanClassName(), holder.getBeanName()); } } } // 以下代码为获取BeanDefinition的具体流程 // ComponentScanAnnotationParser.class public Set<BeanDefinitionHolder> parse(AnnotationAttributes componentScan, final String declaringClass) { // 构建扫描器 ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(this.registry, componentScan.getBoolean("useDefaultFilters"), this.environment, this.resourceLoader); // 构建类名生成器 Class<? extends BeanNameGenerator> generatorClass = componentScan.getClass("nameGenerator"); boolean useInheritedGenerator = (BeanNameGenerator.class == generatorClass); scanner.setBeanNameGenerator(useInheritedGenerator ? this.beanNameGenerator : BeanUtils.instantiateClass(generatorClass)); // 获取类的作用域模型 ScopedProxyMode scopedProxyMode = componentScan.getEnum("scopedProxy"); if (scopedProxyMode != ScopedProxyMode.DEFAULT) { scanner.setScopedProxyMode(scopedProxyMode); } else { Class<? extends ScopeMetadataResolver> resolverClass = componentScan.getClass("scopeResolver"); scanner.setScopeMetadataResolver(BeanUtils.instantiateClass(resolverClass)); } // 获取资源模式（注解配置扫描包都是扫描class因此此处为：**/*.class） scanner.setResourcePattern(componentScan.getString("resourcePattern")); // 获取@ComponentScan注解里面配置的include过滤器 for (AnnotationAttributes filter : componentScan.getAnnotationArray("includeFilters")) { for (TypeFilter typeFilter : typeFiltersFor(filter)) { scanner.addIncludeFilter(typeFilter); } } // 获取@ComponentScan注解里面配置的exclude过滤器 for (AnnotationAttributes filter : componentScan.getAnnotationArray("excludeFilters")) { for (TypeFilter typeFilter : typeFiltersFor(filter)) { scanner.addExcludeFilter(typeFilter); } } // 获取@ComponentScan注解里面配置的lazyInit值 boolean lazyInit = componentScan.getBoolean("lazyInit"); if (lazyInit) { scanner.getBeanDefinitionDefaults().setLazyInit(true); } // 获取需要扫描的路径集合 Set<String> basePackages = new LinkedHashSet<>(); String[] basePackagesArray = componentScan.getStringArray("basePackages"); for (String pkg : basePackagesArray) { String[] tokenized = StringUtils.tokenizeToStringArray(this.environment.resolvePlaceholders(pkg), ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS); Collections.addAll(basePackages, tokenized); } for (Class<?> clazz : componentScan.getClassArray("basePackageClasses")) { basePackages.add(ClassUtils.getPackageName(clazz)); } if (basePackages.isEmpty()) { basePackages.add(ClassUtils.getPackageName(declaringClass)); } scanner.addExcludeFilter(new AbstractTypeHierarchyTraversingFilter(false, false) { @Override protected boolean matchClassName(String className) { return declaringClass.equals(className); } }); // 通过扫描器扫描指定路径下的具有@Component注解的类 return scanner.doScan(StringUtils.toStringArray(basePackages)); } // ClassPathBeanDefinitionScanner.class protected Set<BeanDefinitionHolder> doScan(String... basePackages) { Assert.notEmpty(basePackages, "At least one base package must be specified"); Set<BeanDefinitionHolder> beanDefinitions = new LinkedHashSet<>(); for (String basePackage : basePackages) { // 查找所有@Component注解标识的类 Set<BeanDefinition> candidates = findCandidateComponents(basePackage); for (BeanDefinition candidate : candidates) { // 获取作用域元数据 ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(candidate); candidate.setScope(scopeMetadata.getScopeName()); // 生成类名 String beanName = this.beanNameGenerator.generateBeanName(candidate, this.registry); // 对普通的Bean 进行处理 if (candidate instanceof AbstractBeanDefinition) { postProcessBeanDefinition((AbstractBeanDefinition) candidate, beanName); } // 对包含有注解的Bean进行处理，比如@Lazy、@Primary if (candidate instanceof AnnotatedBeanDefinition) { AnnotationConfigUtils.processCommonDefinitionAnnotations((AnnotatedBeanDefinition) candidate); } // 检查当前加载的Bean名称是否有冲突 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; } // ClassPathScanningCandidateComponentProvider.class public Set<BeanDefinition> findCandidateComponents(String basePackage) { if (this.componentsIndex != null && indexSupportsIncludeFilters()) { return addCandidateComponentsFromIndex(this.componentsIndex, basePackage); } else { // 真正开始搜索类的方法 return scanCandidateComponents(basePackage); } } private Set<BeanDefinition> scanCandidateComponents(String basePackage) { Set<BeanDefinition> candidates = new LinkedHashSet<>(); try { // 获取资源的路径 String packageSearchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + resolveBasePackage(basePackage) + 'http://www.likecs.com/' + this.resourcePattern; // 获取所有资源 Resource[] resources = getResourcePatternResolver().getResources(packageSearchPath); boolean traceEnabled = logger.isTraceEnabled(); boolean debugEnabled = logger.isDebugEnabled(); // 为每一个类生成BeanDefinition对象 for (Resource resource : resources) { if (traceEnabled) { logger.trace("Scanning " + resource); } if (resource.isReadable()) { try { MetadataReader metadataReader = getMetadataReaderFactory().getMetadataReader(resource); // 判断是否具有@Component注解 if (isCandidateComponent(metadataReader)) { ScannedGenericBeanDefinition sbd = new ScannedGenericBeanDefinition(metadataReader); sbd.setResource(resource); sbd.setSource(resource); if (isCandidateComponent(sbd)) { if (debugEnabled) { logger.debug("Identified candidate component class: " + resource); } 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 (Throwable ex) { throw new BeanDefinitionStoreException( "Failed to read candidate component class: " + resource, ex); } } else { if (traceEnabled) { logger.trace("Ignored because not readable: " + resource); } } } } catch (IOException ex) { throw new BeanDefinitionStoreException("I/O failure during classpath scanning", ex); } return candidates; }至此，通过@ComponentScan注解配置扫描指定的包，到获取到具体的带有@Component注解的类已经全部获取完毕。
处理@Import注解