springMVC的九大组件组件初始化介绍

springMVC的九大组件组件

/** * 多组件解析器,文件上传 */ /** MultipartResolver used by this servlet. */ @Nullable private MultipartResolver multipartResolver; /** * 区域解析,国际化 */ /** LocaleResolver used by this servlet. */ @Nullable private LocaleResolver localeResolver; /** * 主题解析器,换皮肤之类的 */ /** ThemeResolver used by this servlet. */ @Nullable private ThemeResolver themeResolver; /** * 处理器映射器 url与哪个Handler对应 */ /** List of HandlerMappings used by this servlet. */ @Nullable private List<HandlerMapping> handlerMappings; /** * 处理器适配器 */ /** List of HandlerAdapters used by this servlet. */ @Nullable private List<HandlerAdapter> handlerAdapters; /** * 异常解析器,处理异常 */ /** List of HandlerExceptionResolvers used by this servlet. */ @Nullable private List<HandlerExceptionResolver> handlerExceptionResolvers; /** * 默认视图名转换器组牛 */ /** RequestToViewNameTranslator used by this servlet. */ @Nullable private RequestToViewNameTranslator viewNameTranslator; /** * 管理Flash属性的 */ /** FlashMapManager used by this servlet. */ @Nullable private FlashMapManager flashMapManager; /** * 视图解析器 */ /** List of ViewResolvers used by this servlet. */ @Nullable private List<ViewResolver> viewResolvers;

九大组件都是接口,

在哪初始化

在容器启动时…hehe

org.springframework.web.servlet.DispatcherServlet#onRefresh

@Override protected void onRefresh(ApplicationContext context) { initStrategies(context); }

org.springframework.web.servlet.DispatcherServlet#initStrategies

protected void initStrategies(ApplicationContext context) { /** * 初始化多组件,上传组件 */ initMultipartResolver(context); /** * 本地语言,国际化 */ initLocaleResolver(context); /** * 主题 */ initThemeResolver(context); /** * HandlerMapping */ initHandlerMappings(context); /** * HandlerAdapter */ initHandlerAdapters(context); /** * 异常 */ initHandlerExceptionResolvers(context); /** * 默认视图处理器 */ initRequestToViewNameTranslator(context); /** * 视图解析器 */ initViewResolvers(context); /** * FlashMapManager,主要用于重定向 */ initFlashMapManager(context); }

调用链onRefresh

spring有自己的默认实现

private static final String DEFAULT_STRATEGIES_PATH = "DispatcherServlet.properties"; static { // Load default strategy implementations from properties file. // This is currently strictly internal and not meant to be customized // by application developers. try { ClassPathResource resource = new ClassPathResource(DEFAULT_STRATEGIES_PATH, DispatcherServlet.class); defaultStrategies = PropertiesLoaderUtils.loadProperties(resource); } catch (IOException ex) { throw new IllegalStateException("Could not load '" + DEFAULT_STRATEGIES_PATH + "': " + ex.getMessage()); } }

org.springframework.web.servlet.LocaleResolver=org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver org.springframework.web.servlet.ThemeResolver=org.springframework.web.servlet.theme.FixedThemeResolver org.springframework.web.servlet.HandlerMapping=org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,\ org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping org.springframework.web.servlet.HandlerAdapter=org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,\ org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,\ org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter org.springframework.web.servlet.HandlerExceptionResolver=org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver,\ org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver,\ org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver org.springframework.web.servlet.RequestToViewNameTranslator=org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator org.springframework.web.servlet.ViewResolver=org.springframework.web.servlet.view.InternalResourceViewResolver org.springframework.web.servlet.FlashMapManager=org.springframework.web.servlet.support.SessionFlashMapManager

initMultipartResolver

private void initMultipartResolver(ApplicationContext context) { try { // public static final String MULTIPART_RESOLVER_BEAN_NAME = "multipartResolver"; /* 去IOC容器中找multipartResolver Bean ->id */ this.multipartResolver = context.getBean(MULTIPART_RESOLVER_BEAN_NAME, MultipartResolver.class); if (logger.isTraceEnabled()) { logger.trace("Detected " + this.multipartResolver); } else if (logger.isDebugEnabled()) { logger.debug("Detected " + this.multipartResolver.getClass().getSimpleName()); } } catch (NoSuchBeanDefinitionException ex) { // Default is no multipart resolver. this.multipartResolver = null; if (logger.isTraceEnabled()) { logger.trace("No MultipartResolver '" + MULTIPART_RESOLVER_BEAN_NAME + "' declared"); } } }

bean id是固定,在xml中配置类似,其他组件也都是上面的获取方式

<!--文件上传--> <!-- servlet3内置文件上传 --> <bean id="multipartResolver" class="org.springframework.web.multipart.support.StandardServletMultipartResolver"> </bean> <!--org.springframework.web.multipart.commons.CommonsMultipartResolver--> <!-- <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="5000000"/> </bean>-->

initHandlerMappings

private void initHandlerMappings(ApplicationContext context) { this.handlerMappings = null; // private boolean detectAllHandlerMappings = true; if (this.detectAllHandlerMappings) { /** * 当前的上下文和父上下文去找所有的 HandlerMapping类型的处理器,默认实现会被先加载 */ // Find all HandlerMappings in the ApplicationContext, including ancestor contexts. Map<String, HandlerMapping> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerMapping.class, true, false); if (!matchingBeans.isEmpty()) { this.handlerMappings = new ArrayList<>(matchingBeans.values()); // We keep HandlerMappings in sorted order. AnnotationAwareOrderComparator.sort(this.handlerMappings); } } else { try { // public static final String HANDLER_MAPPING_BEAN_NAME = "handlerMapping"; HandlerMapping hm = context.getBean(HANDLER_MAPPING_BEAN_NAME, HandlerMapping.class); this.handlerMappings = Collections.singletonList(hm); } catch (NoSuchBeanDefinitionException ex) { // Ignore, we'll add a default HandlerMapping later. } } // Ensure we have at least one HandlerMapping, by registering // a default HandlerMapping if no other mappings are found. if (this.handlerMappings == null) { this.handlerMappings = getDefaultStrategies(context, HandlerMapping.class); if (logger.isTraceEnabled()) { logger.trace("No HandlerMappings declared for servlet '" + getServletName() + "': using default strategies from DispatcherServlet.properties"); } } }

initHandlerAdapters

private void initHandlerAdapters(ApplicationContext context) { this.handlerAdapters = null; //private boolean detectAllHandlerAdapters = true; if (this.detectAllHandlerAdapters) { /** * 当前 人上下文与父上下文中找到所有 */ // Find all HandlerAdapters in the ApplicationContext, including ancestor contexts. Map<String, HandlerAdapter> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerAdapter.class, true, false); if (!matchingBeans.isEmpty()) { this.handlerAdapters = new ArrayList<>(matchingBeans.values()); // We keep HandlerAdapters in sorted order. AnnotationAwareOrderComparator.sort(this.handlerAdapters); } } else { try { // public static final String HANDLER_ADAPTER_BEAN_NAME = "handlerAdapter"; HandlerAdapter ha = context.getBean(HANDLER_ADAPTER_BEAN_NAME, HandlerAdapter.class); this.handlerAdapters = Collections.singletonList(ha); } catch (NoSuchBeanDefinitionException ex) { // Ignore, we'll add a default HandlerAdapter later. } } // Ensure we have at least some HandlerAdapters, by registering // default HandlerAdapters if no other adapters are found. if (this.handlerAdapters == null) { this.handlerAdapters = getDefaultStrategies(context, HandlerAdapter.class); if (logger.isTraceEnabled()) { logger.trace("No HandlerAdapters declared for servlet '" + getServletName() + "': using default strategies from DispatcherServlet.properties"); } } }

initRequestToViewNameTranslator

private void initHandlerExceptionResolvers(ApplicationContext context) { this.handlerExceptionResolvers = null; //private boolean detectAllHandlerExceptionResolvers = true; if (this.detectAllHandlerExceptionResolvers) { // Find all HandlerExceptionResolvers in the ApplicationContext, including ancestor contexts. Map<String, HandlerExceptionResolver> matchingBeans = BeanFactoryUtils .beansOfTypeIncludingAncestors(context, HandlerExceptionResolver.class, true, false); if (!matchingBeans.isEmpty()) { this.handlerExceptionResolvers = new ArrayList<>(matchingBeans.values()); // We keep HandlerExceptionResolvers in sorted order. AnnotationAwareOrderComparator.sort(this.handlerExceptionResolvers); } } else { try { // public static final String HANDLER_EXCEPTION_RESOLVER_BEAN_NAME = "handlerExceptionResolver"; HandlerExceptionResolver her = context.getBean(HANDLER_EXCEPTION_RESOLVER_BEAN_NAME, HandlerExceptionResolver.class); this.handlerExceptionResolvers = Collections.singletonList(her); } catch (NoSuchBeanDefinitionException ex) { // Ignore, no HandlerExceptionResolver is fine too. } } // Ensure we have at least some HandlerExceptionResolvers, by registering // default HandlerExceptionResolvers if no other resolvers are found. if (this.handlerExceptionResolvers == null) { this.handlerExceptionResolvers = getDefaultStrategies(context, HandlerExceptionResolver.class); if (logger.isTraceEnabled()) { logger.trace("No HandlerExceptionResolvers declared in servlet '" + getServletName() + "': using default strategies from DispatcherServlet.properties"); } } }

initRequestToViewNameTranslator

private void initRequestToViewNameTranslator(ApplicationContext context) { try { //public static final String THEME_RESOLVER_BEAN_NAME = "themeResolver"; this.viewNameTranslator = context.getBean(REQUEST_TO_VIEW_NAME_TRANSLATOR_BEAN_NAME, RequestToViewNameTranslator.class); if (logger.isTraceEnabled()) { logger.trace("Detected " + this.viewNameTranslator.getClass().getSimpleName()); } else if (logger.isDebugEnabled()) { logger.debug("Detected " + this.viewNameTranslator); } } catch (NoSuchBeanDefinitionException ex) { // We need to use the default. this.viewNameTranslator = getDefaultStrategy(context, RequestToViewNameTranslator.class); if (logger.isTraceEnabled()) { logger.trace("No RequestToViewNameTranslator '" + REQUEST_TO_VIEW_NAME_TRANSLATOR_BEAN_NAME + "': using default [" + this.viewNameTranslator.getClass().getSimpleName() + "]"); } } }

initViewResolvers

private void initViewResolvers(ApplicationContext context) { this.viewResolvers = null; if (this.detectAllViewResolvers) { // Find all ViewResolvers in the ApplicationContext, including ancestor contexts. Map<String, ViewResolver> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(context, ViewResolver.class, true, false); if (!matchingBeans.isEmpty()) { this.viewResolvers = new ArrayList<>(matchingBeans.values()); // We keep ViewResolvers in sorted order. AnnotationAwareOrderComparator.sort(this.viewResolvers); } } else { try { //public static final String VIEW_RESOLVER_BEAN_NAME = "viewResolver"; ViewResolver vr = context.getBean(VIEW_RESOLVER_BEAN_NAME, ViewResolver.class); this.viewResolvers = Collections.singletonList(vr); } catch (NoSuchBeanDefinitionException ex) { // Ignore, we'll add a default ViewResolver later. } } // Ensure we have at least one ViewResolver, by registering // a default ViewResolver if no other resolvers are found. if (this.viewResolvers == null) { this.viewResolvers = getDefaultStrategies(context, ViewResolver.class); if (logger.isTraceEnabled()) { logger.trace("No ViewResolvers declared for servlet '" + getServletName() + "': using default strategies from DispatcherServlet.properties"); } } }

initFlashMapManager

private void initFlashMapManager(ApplicationContext context) { try { // public static final String FLASH_MAP_MANAGER_BEAN_NAME = "flashMapManager"; this.flashMapManager = context.getBean(FLASH_MAP_MANAGER_BEAN_NAME, FlashMapManager.class); if (logger.isTraceEnabled()) { logger.trace("Detected " + this.flashMapManager.getClass().getSimpleName()); } else if (logger.isDebugEnabled()) { logger.debug("Detected " + this.flashMapManager); } } catch (NoSuchBeanDefinitionException ex) { // We need to use the default. this.flashMapManager = getDefaultStrategy(context, FlashMapManager.class); if (logger.isTraceEnabled()) { logger.trace("No FlashMapManager '" + FLASH_MAP_MANAGER_BEAN_NAME + "': using default [" + this.flashMapManager.getClass().getSimpleName() + "]"); } }

九大组件

配合下面的属性

/** Detect all HandlerMappings or just expect "handlerMapping" bean?. */ private boolean detectAllHandlerMappings = true; /** Detect all HandlerAdapters or just expect "handlerAdapter" bean?. */ private boolean detectAllHandlerAdapters = true; /** Detect all HandlerExceptionResolvers or just expect "handlerExceptionResolver" bean?. */ private boolean detectAllHandlerExceptionResolvers = true; /** Detect all ViewResolvers or just expect "viewResolver" bean?. */ private boolean detectAllViewResolvers = true; /** Throw a NoHandlerFoundException if no Handler was found to process this request? *.*/ private boolean throwExceptionIfNoHandlerFound = false; /** Perform cleanup of request attributes after include request?. */ private boolean cleanupAfterInclude = true;

属性都可以通过配置更改,但Bean的id是固定的,如果自定义只能下面这些名称

public static final String MULTIPART_RESOLVER_BEAN_NAME = "multipartResolver"; /** Well-known name for the LocaleResolver object in the bean factory for this namespace. */ public static final String LOCALE_RESOLVER_BEAN_NAME = "localeResolver"; /** Well-known name for the ThemeResolver object in the bean factory for this namespace. */ public static final String THEME_RESOLVER_BEAN_NAME = "themeResolver"; /** * Well-known name for the HandlerMapping object in the bean factory for this namespace. * Only used when "detectAllHandlerMappings" is turned off. * @see #setDetectAllHandlerMappings */ public static final String HANDLER_MAPPING_BEAN_NAME = "handlerMapping"; /** * Well-known name for the HandlerAdapter object in the bean factory for this namespace. * Only used when "detectAllHandlerAdapters" is turned off. * @see #setDetectAllHandlerAdapters */ public static final String HANDLER_ADAPTER_BEAN_NAME = "handlerAdapter"; /** * Well-known name for the HandlerExceptionResolver object in the bean factory for this namespace. * Only used when "detectAllHandlerExceptionResolvers" is turned off. * @see #setDetectAllHandlerExceptionResolvers */ public static final String HANDLER_EXCEPTION_RESOLVER_BEAN_NAME = "handlerExceptionResolver"; /** * Well-known name for the RequestToViewNameTranslator object in the bean factory for this namespace. */ public static final String REQUEST_TO_VIEW_NAME_TRANSLATOR_BEAN_NAME = "viewNameTranslator"; /** * Well-known name for the ViewResolver object in the bean factory for this namespace. * Only used when "detectAllViewResolvers" is turned off. * @see #setDetectAllViewResolvers */ public static final String VIEW_RESOLVER_BEAN_NAME = "viewResolver"; /** * Well-known name for the FlashMapManager object in the bean factory for this namespace. */ public static final String FLASH_MAP_MANAGER_BEAN_NAME = "flashMapManager";