1. ComponentScanAnnotationParser属性解析

	private final Environment environment;// 用于获取当前应用运行时的配置信息，包括但不限于系统属性、环境变量以及通过PropertySource添加// 的各种属性源。在处理@ComponentScan时，可能需要根据环境来决定哪些包或类应该被扫描。private final ResourceLoader resourceLoader;// spring资源加载器，用于加载不同类型的资源(如文件、类路径资源等)。在执行组件扫描时，可能需要// 加载指定包下面的所有类，这就需要用到ResourceLoader。private final BeanNameGenerator beanNameGenerator;// 一个策略接口实现，用于生成那些未明确提供名称的bean的默认名称。在扫描并创建bean的过程中，如//果没有未某个@Component或者@Service等注解的类显式设置beanName，则会用到此接口来生成唯一且有意	// 义的bean名称。private final BeanDefinitionRegistry registry;// SpringIOC容器的核心组件之一，它是所有BeanDefinition的注册表。ComponentScanAnnotationParser在// 解析过程中发现符合组件条件的类后，会将对应的BeanDefinition注册到这个BeanDefinitionRegistry中，// 使得这些类实例化后可以作为spring容器管理的bean进行依赖注入和生命周期管理。

2. 一个重要方法—parse

public Set<BeanDefinitionHolder> parse(AnnotationAttributes componentScan, String declaringClass) {// 创建类路径bean定义扫描ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(this.registry,componentScan.getBoolean("useDefaultFilters"), this.environment, this.resourceLoader);// 获取nameGeneratorClass<? extends BeanNameGenerator> generatorClass = componentScan.getClass("nameGenerator");boolean useInheritedGenerator = (BeanNameGenerator.class == generatorClass);scanner.setBeanNameGenerator(useInheritedGenerator ? this.beanNameGenerator :BeanUtils.instantiateClass(generatorClass));ScopedProxyMode scopedProxyMode = componentScan.getEnum("scopedProxy");if (scopedProxyMode != ScopedProxyMode.DEFAULT) {scanner.setScopedProxyMode(scopedProxyMode);}else {// 获取scope解决器Class<? extends ScopeMetadataResolver> resolverClass = componentScan.getClass("scopeResolver");// 设置scope解决器scanner.setScopeMetadataResolver(BeanUtils.instantiateClass(resolverClass));}// 设置资源模式scanner.setResourcePattern(componentScan.getString("resourcePattern"));// 添加用户自定义的incluedeFilterfor (AnnotationAttributes includeFilterAttributes : componentScan.getAnnotationArray("includeFilters")) {List<TypeFilter> typeFilters = TypeFilterUtils.createTypeFiltersFor(includeFilterAttributes, this.environment,this.resourceLoader, this.registry);for (TypeFilter typeFilter : typeFilters) {scanner.addIncludeFilter(typeFilter);}}// 添加用户自定义的excludeFilterfor (AnnotationAttributes excludeFilterAttributes : componentScan.getAnnotationArray("excludeFilters")) {List<TypeFilter> typeFilters = TypeFilterUtils.createTypeFiltersFor(excludeFilterAttributes, this.environment,this.resourceLoader, this.registry);for (TypeFilter typeFilter : typeFilters) {scanner.addExcludeFilter(typeFilter);}}// 设置懒initboolean lazyInit = componentScan.getBoolean("lazyInit");if (lazyInit) {scanner.getBeanDefinitionDefaults().setLazyInit(true);}Set<String> basePackages = new LinkedHashSet<>();// 获取basePackagesString[] 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));}// 如果为空, 则指定当前的配置类为基础包if (basePackages.isEmpty()) {basePackages.add(ClassUtils.getPackageName(declaringClass));}// 为了确保声明了@ComponentScan注解的类自身不会被扫描并注册为Bean。因为在大多数情况下，// 我们并不希望扫描器将包含@ComponentScan注解的类当作一个组件来处理。scanner.addExcludeFilter(new AbstractTypeHierarchyTraversingFilter(false, false) {@Overrideprotected boolean matchClassName(String className) {return declaringClass.equals(className);}});// 调用ClassPathBeanDefinitionScanner#doScan方法,返回Set<BeanDefinitionHolder>return scanner.doScan(StringUtils.toStringArray(basePackages));}