springmvc原始碼解析MvcNamespaceHandler之<mvc:resources/>
阿新 • • 發佈：2019-03-16
說在前面
本次主要介紹springmvc配置解析。
springmvc配置解析
本次介紹MvcNamespaceHandler。
進入到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#parse
@Override
public BeanDefinition parse(Element element, ParserContext context) {
Object source = context.extractSource(element);
// 註冊url服務處理器 ->
registerUrlProvider(context, source);
// 註冊路徑匹配器bean定義 ->
RuntimeBeanReference pathMatcherRef = MvcNamespaceUtils.registerPathMatcher(null, context, source);
// 註冊url路徑匹配器bean定義 ->
RuntimeBeanReference pathHelperRef = MvcNamespaceUtils.registerUrlPathHelper(null, context, source);
// 註冊resourceHandler ->
String resourceHandlerName = registerResourceHandler(context, element, pathHelperRef, source);
if (resourceHandlerName == null) {
return null;
}
Map<String, String> urlMap = new ManagedMap<String, String>();
// 解析對映
String resourceRequestPath = element.getAttribute("mapping");
if (!StringUtils.hasText(resourceRequestPath)) {
context.getReaderContext().error("The 'mapping' attribute is required.", context.extractSource(element));
return null;
}
urlMap.put(resourceRequestPath, resourceHandlerName);
// 註冊SimpleUrlHandlerMapping bean定義
RootBeanDefinition handlerMappingDef = new RootBeanDefinition(SimpleUrlHandlerMapping.class);
handlerMappingDef.setSource(source);
handlerMappingDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
handlerMappingDef.getPropertyValues().add("urlMap", urlMap);
handlerMappingDef.getPropertyValues().add("pathMatcher", pathMatcherRef).add("urlPathHelper", pathHelperRef);
// 解析順序屬性
String orderValue = element.getAttribute("order");
// Use a default of near-lowest precedence, still allowing for even lower precedence in other mappings
Object order = StringUtils.hasText(orderValue) ? orderValue : Ordered.LOWEST_PRECEDENCE - 1;
handlerMappingDef.getPropertyValues().add("order", order);
// 註冊跨域bean支援bean定義 ->
RuntimeBeanReference corsRef = MvcNamespaceUtils.registerCorsConfigurations(null, context, source);
handlerMappingDef.getPropertyValues().add("corsConfigurations", corsRef);
String beanName = context.getReaderContext().generateBeanName(handlerMappingDef);
context.getRegistry().registerBeanDefinition(beanName, handlerMappingDef);
context.registerComponent(new BeanComponentDefinition(handlerMappingDef, beanName));
// Ensure BeanNameUrlHandlerMapping (SPR-8289) and default HandlerAdapters are not "turned off"
// Register HttpRequestHandlerAdapter 註冊預設元件 ->
MvcNamespaceUtils.registerDefaultComponents(context, source);
return null;
}進入到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#registerUrlProvider
private void registerUrlProvider(ParserContext context, Object source) {
if (!context.getRegistry().containsBeanDefinition(RESOURCE_URL_PROVIDER)) {
RootBeanDefinition urlProvider = new RootBeanDefinition(ResourceUrlProvider.class);
urlProvider.setSource(source);
urlProvider.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
context.getRegistry().registerBeanDefinition(RESOURCE_URL_PROVIDER, urlProvider);
// 註冊mvcResourceUrlProvider bean定義
context.registerComponent(new BeanComponentDefinition(urlProvider, RESOURCE_URL_PROVIDER));
// 註冊ResourceUrlProviderExposingInterceptor bean定義
RootBeanDefinition interceptor = new RootBeanDefinition(ResourceUrlProviderExposingInterceptor.class);
interceptor.setSource(source);
interceptor.getConstructorArgumentValues().addIndexedArgumentValue(0, urlProvider);
// 註冊MappedInterceptor bean定義
RootBeanDefinition mappedInterceptor = new RootBeanDefinition(MappedInterceptor.class);
mappedInterceptor.setSource(source);
mappedInterceptor.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
mappedInterceptor.getConstructorArgumentValues().addIndexedArgumentValue(0, (Object) null);
mappedInterceptor.getConstructorArgumentValues().addIndexedArgumentValue(1, interceptor);
String mappedInterceptorName = context.getReaderContext().registerWithGeneratedName(mappedInterceptor);
context.registerComponent(new BeanComponentDefinition(mappedInterceptor, mappedInterceptorName));
}
}往上返回到這個方法org.springframework.web.servlet.config.MvcNamespaceUtils#registerPathMatcher
public static RuntimeBeanReference registerPathMatcher(
RuntimeBeanReference pathMatcherRef, ParserContext parserContext, Object source) {
if (pathMatcherRef != null) {
if (parserContext.getRegistry().isAlias(PATH_MATCHER_BEAN_NAME)) {
parserContext.getRegistry().removeAlias(PATH_MATCHER_BEAN_NAME);
}
// 註冊別名mvcPathMatcher
parserContext.getRegistry().registerAlias(pathMatcherRef.getBeanName(), PATH_MATCHER_BEAN_NAME);
}
else if (!parserContext.getRegistry().isAlias(PATH_MATCHER_BEAN_NAME)
&& !parserContext.getRegistry().containsBeanDefinition(PATH_MATCHER_BEAN_NAME)) {
RootBeanDefinition pathMatcherDef = new RootBeanDefinition(AntPathMatcher.class);
pathMatcherDef.setSource(source);
pathMatcherDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
// 註冊mvcPathMatcher bean定義
parserContext.getRegistry().registerBeanDefinition(PATH_MATCHER_BEAN_NAME, pathMatcherDef);
parserContext.registerComponent(new BeanComponentDefinition(pathMatcherDef, PATH_MATCHER_BEAN_NAME));
}
return new RuntimeBeanReference(PATH_MATCHER_BEAN_NAME);
}往上返回到這個方法org.springframework.web.servlet.config.MvcNamespaceUtils#registerUrlPathHelper
public static RuntimeBeanReference registerUrlPathHelper(
RuntimeBeanReference urlPathHelperRef, ParserContext parserContext, Object source) {
if (urlPathHelperRef != null) {
if (parserContext.getRegistry().isAlias(URL_PATH_HELPER_BEAN_NAME)) {
parserContext.getRegistry().removeAlias(URL_PATH_HELPER_BEAN_NAME);
}
// 註冊mvcUrlPathHelper別名
parserContext.getRegistry().registerAlias(urlPathHelperRef.getBeanName(), URL_PATH_HELPER_BEAN_NAME);
}
else if (!parserContext.getRegistry().isAlias(URL_PATH_HELPER_BEAN_NAME)
&& !parserContext.getRegistry().containsBeanDefinition(URL_PATH_HELPER_BEAN_NAME)) {
RootBeanDefinition urlPathHelperDef = new RootBeanDefinition(UrlPathHelper.class);
urlPathHelperDef.setSource(source);
urlPathHelperDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
// 註冊mvcUrlPathHelper bean定義
parserContext.getRegistry().registerBeanDefinition(URL_PATH_HELPER_BEAN_NAME, urlPathHelperDef);
parserContext.registerComponent(new BeanComponentDefinition(urlPathHelperDef, URL_PATH_HELPER_BEAN_NAME));
}
return new RuntimeBeanReference(URL_PATH_HELPER_BEAN_NAME);
}
往上返回到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#registerResourceHandler
private String registerResourceHandler(
ParserContext context, Element element, RuntimeBeanReference pathHelperRef, Object source) {
// 解析location屬性值
String locationAttr = element.getAttribute("location");
if (!StringUtils.hasText(locationAttr)) {
context.getReaderContext().error("The 'location' attribute is required.", context.extractSource(element));
return null;
}
// 註冊ResourceHttpRequestHandler bean定義
RootBeanDefinition resourceHandlerDef = new RootBeanDefinition(ResourceHttpRequestHandler.class);
resourceHandlerDef.setSource(source);
resourceHandlerDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
MutablePropertyValues values = resourceHandlerDef.getPropertyValues();
// 解析url路徑解析器
values.add("urlPathHelper", pathHelperRef);
// 解析路徑值
values.add("locationValues", StringUtils.commaDelimitedListToStringArray(locationAttr));
// 獲取快取週期
String cacheSeconds = element.getAttribute("cache-period");
if (StringUtils.hasText(cacheSeconds)) {
values.add("cacheSeconds", cacheSeconds);
}
// 獲取快取配置
Element cacheControlElement = DomUtils.getChildElementByTagName(element, "cache-control");
if (cacheControlElement != null) {
// 解析快取配置 ->
CacheControl cacheControl = parseCacheControl(cacheControlElement);
values.add("cacheControl", cacheControl);
}
// 獲取資源域屬性
Element resourceChainElement = DomUtils.getChildElementByTagName(element, "resource-chain");
if (resourceChainElement != null) {
// 解析資源域 ->
parseResourceChain(resourceHandlerDef, context, resourceChainElement, source);
}
// 獲取媒體型別管理器 ->
Object manager = MvcNamespaceUtils.getContentNegotiationManager(context);
if (manager != null) {
values.add("contentNegotiationManager", manager);
}
String beanName = context.getReaderContext().generateBeanName(resourceHandlerDef);
context.getRegistry().registerBeanDefinition(beanName, resourceHandlerDef);
context.registerComponent(new BeanComponentDefinition(resourceHandlerDef, beanName));
return beanName;
}
進入到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#parseResourceChain
private void parseResourceChain(
RootBeanDefinition resourceHandlerDef, ParserContext context, Element element, Object source) {
String autoRegistration = element.getAttribute("auto-registration");
boolean isAutoRegistration = !(StringUtils.hasText(autoRegistration) && "false".equals(autoRegistration));
ManagedList<Object> resourceResolvers = new ManagedList<Object>();
resourceResolvers.setSource(source);
ManagedList<Object> resourceTransformers = new ManagedList<Object>();
resourceTransformers.setSource(source);
// 解析資源快取 ->
parseResourceCache(resourceResolvers, resourceTransformers, element, source);
// 解析資源解析轉換器
parseResourceResolversTransformers(
isAutoRegistration, resourceResolvers, resourceTransformers, context, element, source);
if (!resourceResolvers.isEmpty()) {
resourceHandlerDef.getPropertyValues().add("resourceResolvers", resourceResolvers);
}
if (!resourceTransformers.isEmpty()) {
resourceHandlerDef.getPropertyValues().add("resourceTransformers", resourceTransformers);
}
}
進入到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#parseResourceCache
private void parseResourceCache(ManagedList<Object> resourceResolvers,
ManagedList<Object> resourceTransformers, Element element, Object source) {
String resourceCache = element.getAttribute("resource-cache");
if ("true".equals(resourceCache)) {
ConstructorArgumentValues cargs = new ConstructorArgumentValues();
// 註冊CachingResourceResolver bean定義
RootBeanDefinition cachingResolverDef = new RootBeanDefinition(CachingResourceResolver.class);
cachingResolverDef.setSource(source);
cachingResolverDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
cachingResolverDef.setConstructorArgumentValues(cargs);
// 註冊CachingResourceTransformer bean定義
RootBeanDefinition cachingTransformerDef = new RootBeanDefinition(CachingResourceTransformer.class);
cachingTransformerDef.setSource(source);
cachingTransformerDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
cachingTransformerDef.setConstructorArgumentValues(cargs);
// 獲取快取管理器配置
String cacheManagerName = element.getAttribute("cache-manager");
String cacheName = element.getAttribute("cache-name");
if (StringUtils.hasText(cacheManagerName) && StringUtils.hasText(cacheName)) {
RuntimeBeanReference cacheManagerRef = new RuntimeBeanReference(cacheManagerName);
cargs.addIndexedArgumentValue(0, cacheManagerRef);
cargs.addIndexedArgumentValue(1, cacheName);
}
else {
ConstructorArgumentValues cacheCavs = new ConstructorArgumentValues();
cacheCavs.addIndexedArgumentValue(0, RESOURCE_CHAIN_CACHE);
// 註冊ConcurrentMapCache bean定義
RootBeanDefinition cacheDef = new RootBeanDefinition(ConcurrentMapCache.class);
cacheDef.setSource(source);
cacheDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
cacheDef.setConstructorArgumentValues(cacheCavs);
cargs.addIndexedArgumentValue(0, cacheDef);
}
resourceResolvers.add(cachingResolverDef);
resourceTransformers.add(cachingTransformerDef);
}
}
往上返回到這個方法org.springframework.web.servlet.config.MvcNamespaceUtils#getContentNegotiationManager
public static Object getContentNegotiationManager(ParserContext context) {
String name = AnnotationDrivenBeanDefinitionParser.HANDLER_MAPPING_BEAN_NAME;
if (context.getRegistry().containsBeanDefinition(name)) {
BeanDefinition handlerMappingBeanDef = context.getRegistry().getBeanDefinition(name);
// 從RequestMappingHandlerMapping bean定義中獲取
return handlerMappingBeanDef.getPropertyValues().get("contentNegotiationManager");
}
name = AnnotationDrivenBeanDefinitionParser.CONTENT_NEGOTIATION_MANAGER_BEAN_NAME;
if (context.getRegistry().containsBeanDefinition(name)) {
return new RuntimeBeanReference(name);
}
return null;
}
往上返回到這個方法org.springframework.web.servlet.config.MvcNamespaceUtils#registerCorsConfigurations
public static RuntimeBeanReference registerCorsConfigurations(
Map<String, CorsConfiguration> corsConfigurations, ParserContext context, Object source) {
// mvcCorsConfigurations 跨域支援bean定義解析
if (!context.getRegistry().containsBeanDefinition(CORS_CONFIGURATION_BEAN_NAME)) {
RootBeanDefinition corsDef = new RootBeanDefinition(LinkedHashMap.class);
corsDef.setSource(source);
corsDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
if (corsConfigurations != null) {
corsDef.getConstructorArgumentValues().addIndexedArgumentValue(0, corsConfigurations);
}
// 註冊mvcCorsConfigurations bean定義
context.getReaderContext().getRegistry().registerBeanDefinition(CORS_CONFIGURATION_BEAN_NAME, corsDef);
context.registerComponent(new BeanComponentDefinition(corsDef, CORS_CONFIGURATION_BEAN_NAME));
}
else if (corsConfigurations != null) {
BeanDefinition corsDef = context.getRegistry().getBeanDefinition(CORS_CONFIGURATION_BEAN_NAME);
corsDef.getConstructorArgumentValues().addIndexedArgumentValue(0, corsConfigurations);
}
return new RuntimeBeanReference(CORS_CONFIGURATION_BEAN_NAME);
}
往上返回到這個方法org.springframework.web.servlet.config.MvcNamespaceUtils#registerDefaultComponents
public static void registerDefaultComponents(ParserContext parserContext, Object source) {
// 註冊BeanNameUrlHandlerMapping bean定義 ->
registerBeanNameUrlHandlerMapping(parserContext, source);
// 註冊HttpRequestHandlerAdapter bean定義 ->
registerHttpRequestHandlerAdapter(parserContext, source);
// 註冊SimpleControllerHandlerAdapter bean定義 ->
registerSimpleControllerHandlerAdapter(parserContext, source);
// 註冊HandlerMappingIntrospector bean定義 ->
registerHandlerMappingIntrospector(parserContext, source);
}
這裡前面解析過了。
往上返回到這個方法org.springframework.web.servlet.config.ResourcesBeanDefinitionParser#parse
說到最後
本次原始碼解析僅代表個人觀點，僅供參