springMVC的九大組件組件初始化介紹

springMVC的九大組件組件

/**
	 * 多組件解析器,文件上傳
	 */
	/** MultipartResolver used by this servlet. */
	@Nullable
	private MultipartResolver multipartResolver;
	/**
	 * 區域解析,國際化
	 */
	/** LocaleResolver used by this servlet. */
	@Nullable
	private LocaleResolver localeResolver;

	/**
	 * 主題解析器,換皮膚之類的
	 */
	/** ThemeResolver used by this servlet. */
	@Nullable
	private ThemeResolver themeResolver;

	/**
	 * 處理器映射器 url與哪個Handler對應
	 */
	/** List of HandlerMappings used by this servlet. */
	@Nullable
	private List<HandlerMapping> handlerMappings;

	/**
	 * 處理器適配器 
	 */
	/** List of HandlerAdapters used by this servlet. */
	@Nullable
	private List<HandlerAdapter> handlerAdapters;

	/**
	 * 異常解析器,處理異常
	 */
	/** List of HandlerExceptionResolvers used by this servlet. */
	@Nullable
	private List<HandlerExceptionResolver> handlerExceptionResolvers;

	/**
	 * 默認視圖名轉換器組牛
	 */
	/** RequestToViewNameTranslator used by this servlet. */
	@Nullable
	private RequestToViewNameTranslator viewNameTranslator;

	/**
	 * 管理Flash屬性的
	 */
	/** FlashMapManager used by this servlet. */
	@Nullable
	private FlashMapManager flashMapManager;
	/**
	 * 視圖解析器
	 */
	/** List of ViewResolvers used by this servlet. */
	@Nullable
	private List<ViewResolver> viewResolvers;

九大組件都是接口,

在哪初始化

在容器啓動時…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) {
		/**
		 * 初始化多組件,上傳組件
		 */
		initMultipartResolver(context);
		/**
		 * 本地語言,國際化
		 */
		initLocaleResolver(context);
		/**
		 * 主題
		 */
		initThemeResolver(context);
		/**
		 * HandlerMapping
		 */
		initHandlerMappings(context);
		/**
		 * HandlerAdapter
		 */
		initHandlerAdapters(context);
		/**
		 * 異常
		 */
		initHandlerExceptionResolvers(context);
		/**
		 * 默認視圖處理器
		 */
		initRequestToViewNameTranslator(context);
		/**
		 * 視圖解析器
		 */
		initViewResolvers(context);
		/**
		 * FlashMapManager,主要用於重定向
		 */
		initFlashMapManager(context);
	}

調用鏈onRefresh

spring有自己的默認實現

	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中配置類似,其他組件也都是上面的獲取方式

	<!--文件上傳-->
	<!-- servlet3內置文件上傳 -->
	<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) {
			/**
			 * 當前的上下文和父上下文去找所有的 HandlerMapping類型的處理器,默認實現會被先加載
			 */
			// 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) {
			/**
			 * 當前 人上下文與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() + "]");
			}
		}

九大組件

配合下面的屬性

/** 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;

屬性都可以通過配置更改,但Bean的id是固定的,如果自定義只能下面這些名稱

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";