<context:component-scan base-package="com.zhuguang.jack" <!-- 扫描的基本包路径 -->
annotation-config="true" <!-- 是否激活属性注入注解 -->
name-generator="org.springframework.context.annotation.AnnotationBeanNameGenerator" <!-- Bean的ID策略生成器 -->
resource-pattern="**/*.class" <!-- 对资源进行筛选的正则表达式，这边是个大的范畴，具体细分在include-filter与exclude-filter中进行 -->
scope-resolver="org.springframework.context.annotation.AnnotationScopeMetadataResolver" <!-- scope解析器 ，与scoped-proxy只能同时配置一个 -->
scoped-proxy="no" <!-- scope代理，与scope-resolver只能同时配置一个 -->
use-default-filters="false" <!-- 是否使用默认的过滤器，默认值true -->
>
<!-- 注意：若使用include-filter去定制扫描内容，要在use-default-filters="false"的情况下，不然会“失效”，被默认的过滤机制所覆盖 -->
<!-- annotation是对注解进行扫描 ，有这个注解的才会扫描实例化-->
<context:include-filter type="annotation" expression="org.springframework.stereotype.Component"/>
<!-- assignable是对类或接口进行扫描 ，实现这个接口的才会扫描实例化-->
<context:include-filter type="assignable" expression="com.wjx.betalot.performer.Performer"/>
<context:include-filter type="assignable" expression="com.wjx.betalot.performer.impl.Sonnet"/>
<context:exclude-filter type="regex" expression=".controller.*"/>
<!-- 注意：在use-default-filters="false"的情况下，exclude-filter是针对include-filter里的内容进行排除，
有Controller注解的排除， -->
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
<context:exclude-filter type="assignable" expression="com.wjx.betalot.performer.impl.RainPoem"/>
<context:exclude-filter type="regex" expression=".service.*"/>
</context:component-scan>
public BeanDefinition parse(Element element, ParserContext parserContext) {
String[] basePackages = StringUtils.tokenizeToStringArray(element.getAttribute(BASE_PACKAGE_ATTRIBUTE),
ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS); //[com.zhuguang.jack]
ClassPathBeanDefinitionScanner scanner = configureScanner(parserContext, element); //扫描器
Set<BeanDefinitionHolder> beanDefinitions = scanner.doScan(basePackages);
registerComponents(parserContext.getReaderContext(), beanDefinitions, element);
return null;
}
protected ClassPathBeanDefinitionScanner configureScanner(ParserContext parserContext, Element element) {
XmlReaderContext readerContext = parserContext.getReaderContext(); //XmlReaderContext@704deff2
boolean useDefaultFilters = true;
if (element.hasAttribute(USE_DEFAULT_FILTERS_ATTRIBUTE)) {
useDefaultFilters = Boolean.valueOf(element.getAttribute(USE_DEFAULT_FILTERS_ATTRIBUTE)); //默认过滤器
}
ClassPathBeanDefinitionScanner scanner = createScanner(readerContext, useDefaultFilters); //扫描器
return scanner;
}
protected Set<BeanDefinitionHolder> doScan(String... basePackages) {
for (String basePackage : basePackages) {
Set<BeanDefinition> candidates = findCandidateComponents(basePackage); // [[AnnotationServiceImpl];], [CommonController]; ]]，
for (BeanDefinition candidate : candidates) {
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); //往bean定义里面设置属性，setLazyInit，setAutowireMode，setDependencyCheck，setInitMethodName，setEnforceInitMethod，setDestroyMethodName，setEnforceDestroyMethod都设置默认值，
}
if (candidate instanceof AnnotatedBeanDefinition) {
AnnotationConfigUtils.processCommonDefinitionAnnotations((AnnotatedBeanDefinition) candidate); //往bean定义里面设置属性，是否有Lazy，Primary，DependsOn，Role，Description注解，如果有就设置到bean定义中去。
}
if (checkCandidate(beanName, candidate)) {
BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(candidate, beanName); //把BeanDefinition 变成BeanDefinitionHolder，
definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry); //
beanDefinitions.add(definitionHolder);
registerBeanDefinition(definitionHolder, this.registry); //注册到spring容器中，
}
}
}
return beanDefinitions;
}
public Set<BeanDefinition> findCandidateComponents(String basePackage) {
try {
String packageSearchPath = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX +
resolveBasePackage(basePackage) + "/" + this.resourcePattern; //classpath*:com/zhuguang/jack/**/*.class找到所有的。class文件，
Resource[] resources = this.resourcePatternResolver.getResources(packageSearchPath); //[file [E:AnnotationServiceImpl.class], file [E:CommonController.class], file [E:CommonMapper.class], file [E:ConsultConfigArea.class], file [E:ConsultContent.class], file [E:MyService.class], file [E:Test2.class], file [E:User.class]]
for (Resource resource : resources) {
if (isCandidateComponent(metadataReader) && resource.isReadable()) { //没有条件注解，就进来，没有注解的不进来。有@Component注解的才进来，
try {
MetadataReader metadataReader = this.metadataReaderFactory.getMetadataReader(resource); //AnnotationMetadata里面封装了这个类的一些基本信息，类里面有哪些方法，方法上面有哪些注解，类上面有哪些注解，
if (isCandidateComponent(metadataReader)) {//!(this.isInterface || this.isAbstract) && (this.enclosingClassName == null || this.independentInnerClass); 不是接口不是抽象类就进来，CommonMapper是一个接口不进来，
ScannedGenericBeanDefinition sbd = new ScannedGenericBeanDefinition(metadataReader);
sbd.setResource(resource);
sbd.setSource(resource);
if (isCandidateComponent(sbd)) {
candidates.add(sbd);
}
else {
}
}
}
}
}
}
return candidates;
}
public MetadataReader getMetadataReader(Resource resource) throws IOException {
return new SimpleMetadataReader(resource, this.resourceLoader.getClassLoader());
}
SimpleMetadataReader(Resource resource, ClassLoader classLoader) throws IOException {
InputStream is = new BufferedInputStream(resource.getInputStream());//文件流，
ClassReader classReader;
classReader = new ClassReader(is);
AnnotationMetadataReadingVisitor visitor = new AnnotationMetadataReadingVisitor(classLoader);
classReader.accept(visitor, ClassReader.SKIP_DEBUG);
this.annotationMetadata = visitor;
this.classMetadata = visitor;
this.resource = resource;
}
protected boolean isCandidateComponent(MetadataReader metadataReader) throws IOException { //metadataReader是类的元数据信息，
for (TypeFilter tf : this.excludeFilters) {
if (tf.match(metadataReader, this.metadataReaderFactory)) {
return false;
}
}
for (TypeFilter tf : this.includeFilters) {//interface org.springframework.stereotype.Component，interface javax.inject.Named。有@Component注解的才进来，
if (tf.match(metadataReader, this.metadataReaderFactory)) {
return isConditionMatch(metadataReader);
}
}
return false;
}
public Resource[] getResources(String locationPattern) throws IOException {
if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) {
if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()))) {
return findPathMatchingResources(locationPattern);
}
}
}
protected Resource[] findPathMatchingResources(String locationPattern) throws IOException {
String rootDirPath = determineRootDir(locationPattern); //classpath*:com/zhuguang/jack/
String subPattern = locationPattern.substring(rootDirPath.length()); //**/*.class
Resource[] rootDirResources = getResources(rootDirPath); //返回[URL [file:/E:/Code/AAAAA/AAAAA/2019326/2/spring-source-web-master-aop/target/classes/com/zhuguang/jack/]]
Set<Resource> result = new LinkedHashSet<Resource>(16);
for (Resource rootDirResource : rootDirResources) {
rootDirResource = resolveRootDirResource(rootDirResource); //返回[URL [file:/E:/Code/AAAAA/AAAAA/2019326/2/spring-source-web-master-aop/target/classes/com/zhuguang/jack/]]
if (isJarResource(rootDirResource)) {
result.addAll(doFindPathMatchingJarResources(rootDirResource, subPattern));
}
else if (rootDirResource.getURL().getProtocol().startsWith(ResourceUtils.URL_PROTOCOL_VFS)) {
result.addAll(VfsResourceMatchingDelegate.findMatchingResources(rootDirResource, subPattern, getPathMatcher()));
}
else {
result.addAll(doFindPathMatchingFileResources(rootDirResource, subPattern));
}
}
return result.toArray(new Resource[result.size()]); //[file [E:AnnotationServiceImpl.class], file [E:CommonController.class], file [E:CommonMapper.class], file [E:ConsultConfigArea.class], file [E:ConsultContent.class], file [E:MyService.class], file [E:Test2.class], file [E:User.class]]
}
public Resource[] getResources(String locationPattern) throws IOException {
else {
return findAllClassPathResources(locationPattern.substring(CLASSPATH_ALL_URL_PREFIX.length()));
}
}
}
protected Resource[] findAllClassPathResources(String location) throws IOException {
Enumeration<URL> resourceUrls = getClassLoader().getResources(path); //AppClassLoader，返回[sun.misc.CompoundEnumeration@b83a9be, java.net.URLClassLoader$3@2609b277]
Set<Resource> result = new LinkedHashSet<Resource>(16);
while (resourceUrls.hasMoreElements()) {
URL url = resourceUrls.nextElement();
result.add(convertClassLoaderURL(url));
}
return result.toArray(new Resource[result.size()]); //返回[URL [file:/E:/Code/AAAAA/AAAAA/2019326/2/spring-source-web-master-aop/target/classes/com/zhuguang/jack/]]
}
public Enumeration<URL> getResources(String name) throws IOException {
@SuppressWarnings("unchecked")
Enumeration<URL>[] tmp = (Enumeration<URL>[]) new Enumeration<?>[2];
if (parent != null) {
tmp[0] = parent.getResources(name); //ExtClassLoader
} else {
tmp[0] = getBootstrapResources(name);
}
tmp[1] = findResources(name);
return new CompoundEnumeration<>(tmp);
}
private static Enumeration<URL> getBootstrapResources(String name) {
final Enumeration<Resource> e = getBootstrapClassPath().getResources(name); //sun.misc.URLClassPath@28d18df5
return new Enumeration<URL> () {
public URL nextElement() {
return e.nextElement().getURL();
}
public boolean hasMoreElements() {
return e.hasMoreElements();
}
}
}
