org.springframework.web.servlet.DispatcherServlet-doDispatch-processDispatchResult執行介紹

org.springframework.web.servlet.DispatcherServlet-doDispatch

	/**
			 * 8對頁面渲染
			 */
			processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);

org.springframework.web.servlet.DispatcherServlet#processDispatchResult

private void processDispatchResult(HttpServletRequest request, HttpServletResponse response,
			@Nullable HandlerExecutionChain mappedHandler, @Nullable ModelAndView mv,
			@Nullable Exception exception) throws Exception {

		boolean errorView = false;
		//判斷 是否異常
		if (exception != null) {
			if (exception instanceof ModelAndViewDefiningException) {
				logger.debug("ModelAndViewDefiningException encountered", exception);
				mv = ((ModelAndViewDefiningException) exception).getModelAndView();
			}
			else {
				Object handler = (mappedHandler != null ? mappedHandler.getHandler() : null);
				mv = processHandlerException(request, response, handler, exception);
				errorView = (mv != null);
			}
		}
		/**
		 * mv是否爲空,json就爲空
		 */
		// Did the handler return a view to render?
		if (mv != null && !mv.wasCleared()) {
		//渲染視圖
			render(mv, request, response);
			if (errorView) {
				WebUtils.clearErrorRequestAttributes(request);
			}
		}

org.springframework.web.servlet.DispatcherServlet#render

protected void render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response) throws Exception {
		/**
		 * 國際化設置
		 */
		// Determine locale for request and apply it to the response.
		Locale locale =
				(this.localeResolver != null ? this.localeResolver.resolveLocale(request) : request.getLocale());
		response.setLocale(locale);
		/**
		 * 獲取ViewName
		 */
		View view;
		//success
		String viewName = mv.getViewName();
		if (viewName != null) {
			/**
			 * 使用視圖解析器獲取完整的名稱
			 */
			// We need to resolve the view name.
			view = resolveViewName(viewName, mv.getModelInternal(), locale, request);
			if (view == null) {
				throw new ServletException("Could not resolve view with name '" + mv.getViewName() +
						"' in servlet with name '" + getServletName() + "'");
			}
		}
		else {
			// No need to lookup: the ModelAndView object contains the actual View object.
			view = mv.getView();
			if (view == null) {
				throw new ServletException("ModelAndView [" + mv + "] neither contains a view name nor a " +
						"View object in servlet with name '" + getServletName() + "'");
			}
		}

		// Delegate to the View object for rendering.
		if (logger.isTraceEnabled()) {
			logger.trace("Rendering view [" + view + "] ");
		}
		try {
			if (mv.getStatus() != null) {
				response.setStatus(mv.getStatus().value());
			}
			/**
			 * 渲染使用視圖解析器
			 */
			view.render(mv.getModelInternal(), request, response);
		}
		catch (Exception ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("Error rendering view [" + view + "]", ex);
			}
			throw ex;
		}
	}

• resolveViewName
  

• createView
  

org.springframework.web.servlet.view.AbstractCachingViewResolver#createView

org.springframework.web.servlet.view.UrlBasedViewResolver#loadView

org.springframework.web.servlet.view.InternalResourceViewResolver#buildView

org.springframework.web.servlet.view.UrlBasedViewResolver#buildView

org.springframework.web.servlet.view.AbstractView#render

public void render(@Nullable Map<String, ?> model, HttpServletRequest request,
			HttpServletResponse response) throws Exception {

		if (logger.isDebugEnabled()) {
			logger.debug("View " + formatViewName() +
					", model " + (model != null ? model : Collections.emptyMap()) +
					(this.staticAttributes.isEmpty() ? "" : ", static attributes " + this.staticAttributes));
		}
		/**
		 * 得到數據Map信合
		 */
		Map<String, Object> mergedModel = createMergedOutputModel(model, request, response);
		/**
		 * 設置響應頭
		 */
		prepareResponse(request, response);
		/**
		 * 數據渲染
		 */
		renderMergedOutputModel(mergedModel, getRequestToExpose(request), response);
	}

org.springframework.web.servlet.view.InternalResourceView#renderMergedOutputModel

protected void renderMergedOutputModel(
			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
		//循環將數據放入Request域中 request.setAttribute(name, value); jsp中${}取值
		// Expose the model object as request attributes.
		exposeModelAsRequestAttributes(model, request);

		// Expose helpers as request attributes, if any.
		exposeHelpers(request);

		// Determine the path for the request dispatcher.
		String dispatcherPath = prepareForRendering(request, response);

		// Obtain a RequestDispatcher for the target resource (typically a JSP).
		RequestDispatcher rd = getRequestDispatcher(request, dispatcherPath);
		if (rd == null) {
			throw new ServletException("Could not get RequestDispatcher for [" + getUrl() +
					"]: Check that the corresponding file exists within your web application archive!");
		}

		// If already included or response already committed, perform include, else forward.
		if (useInclude(request, response)) {
			response.setContentType(getContentType());
			if (logger.isDebugEnabled()) {
				logger.debug("Including [" + getUrl() + "]");
			}
			rd.include(request, response);
		}

		else {
			// Note: The forwarded resource is supposed to determine the content type itself.
			if (logger.isDebugEnabled()) {
				logger.debug("Forwarding to [" + getUrl() + "]");
			}
			//跳轉頁面
			rd.forward(request, response);
		}
	}

org.springframework.web.servlet.view.AbstractView#exposeModelAsRequestAttributes