dispatcherportlet.java

Spring API核心源代码 Spring API核心源代码 Spring API核心源代码

			String[] classNames = StringUtils.commaDelimitedListToStringArray(value);
			strategies = new ArrayList(classNames.length);
			for (int i = 0; i < classNames.length; i++) {
				String className = classNames[i];
				try {
					Class clazz = ClassUtils.forName(className, getClass().getClassLoader());
					Object strategy = createDefaultStrategy(context, clazz);
					strategies.add(strategy);
				}
				catch (ClassNotFoundException ex) {
					throw new BeanInitializationException(
							"Could not find DispatcherPortlet's default strategy class [" + className +
							"] for interface [" + key + "]", ex);
				}
				catch (LinkageError err) {
					throw new BeanInitializationException(
							"Error loading DispatcherPortlet's default strategy class [" + className +
							"] for interface [" + key + "]: problem with class file or dependent class", err);
				}
			}
		}
		else {
			strategies = Collections.EMPTY_LIST;
		}
		return strategies;
	}

	/**
	 * Create a default strategy.
	 * <p>The default implementation uses
	 * {@link org.springframework.beans.factory.config.AutowireCapableBeanFactory#createBean}.
	 * @param context the current Portlet ApplicationContext
	 * @param clazz the strategy implementation class to instantiate
	 * @return the fully configured strategy instance
	 * @throws BeansException if initialization failed
	 * @see org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory()
	 */
	protected Object createDefaultStrategy(ApplicationContext context, Class clazz) throws BeansException {
		return context.getAutowireCapableBeanFactory().createBean(
				clazz, AutowireCapableBeanFactory.AUTOWIRE_NO, false);
	}


	/**
	 * Obtain this portlet's PortletMultipartResolver, if any.
	 * @return the PortletMultipartResolver used by this portlet, or <code>null</code>
	 * if none (indicating that no multipart support is available)
	 */
	public PortletMultipartResolver getMultipartResolver() {
		return this.multipartResolver;
	}


	/**
	 * Processes the actual dispatching to the handler for action requests.
	 * <p>The handler will be obtained by applying the portlet's HandlerMappings in order.
	 * The HandlerAdapter will be obtained by querying the portlet's installed
	 * HandlerAdapters to find the first that supports the handler class.
	 * @param request current portlet action request
	 * @param response current portlet Action response
	 * @throws Exception in case of any kind of processing failure
	 */
	protected void doActionService(ActionRequest request, ActionResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received action request");
		}

		// Expose current LocaleResolver and request as LocaleContext.
		LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();
		LocaleContextHolder.setLocaleContext(buildLocaleContext(request), this.threadContextInheritable);

		// Expose current RequestAttributes to current thread.
		RequestAttributes previousRequestAttributes = RequestContextHolder.getRequestAttributes();
		PortletRequestAttributes requestAttributes = new PortletRequestAttributes(request);
		RequestContextHolder.setRequestAttributes(requestAttributes, this.threadContextInheritable);

		if (logger.isDebugEnabled()) {
			logger.debug("Bound action request context to thread: " + request);
		}

		ActionRequest processedRequest = request;
		HandlerExecutionChain mappedHandler = null;
		int interceptorIndex = -1;

		try {
			processedRequest = checkMultipart(request);

			// Determine handler for the current request.
			mappedHandler = getHandler(processedRequest, false);
			if (mappedHandler == null || mappedHandler.getHandler() == null) {
				noHandlerFound(processedRequest, response);
				return;
			}

			// Apply preHandle methods of registered interceptors.
			if (mappedHandler.getInterceptors() != null) {
				for (int i = 0; i < mappedHandler.getInterceptors().length; i++) {
					HandlerInterceptor interceptor = mappedHandler.getInterceptors()[i];
					if (!interceptor.preHandleAction(processedRequest, response, mappedHandler.getHandler())) {
						triggerAfterActionCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);
						return;
					}
					interceptorIndex = i;
				}
			}

			// Actually invoke the handler.
			HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
			ha.handleAction(processedRequest, response, mappedHandler.getHandler());

			// Trigger after-completion for successful outcome.
			triggerAfterActionCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);
		}

		catch (Exception ex) {
			// Trigger after-completion for thrown exception.
			triggerAfterActionCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
			// Forward the exception to the render phase to be displayed.
			logger.debug("Caught exception during action phase - forwarding to render phase", ex);
			PortletSession session = request.getPortletSession();
			session.setAttribute(ACTION_EXCEPTION_SESSION_ATTRIBUTE, ex);
			response.setRenderParameter(ACTION_EXCEPTION_RENDER_PARAMETER, ex.toString());
		}
		catch (Error err) {
			PortletException ex =
					new PortletException("Error occured during request processing: " + err.getMessage(), err);
			// Trigger after-completion for thrown exception.
			triggerAfterActionCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
			throw ex;
		}

		finally {
			// Clean up any resources used by a multipart request.
			if (processedRequest instanceof MultipartActionRequest && processedRequest != request) {
				this.multipartResolver.cleanupMultipart((MultipartActionRequest) processedRequest);
			}

			// Reset thread-bound context.
			RequestContextHolder.setRequestAttributes(previousRequestAttributes, this.threadContextInheritable);
			LocaleContextHolder.setLocaleContext(previousLocaleContext, this.threadContextInheritable);

			// Clear request attributes.
			requestAttributes.requestCompleted();
			if (logger.isDebugEnabled()) {
				logger.debug("Cleared thread-bound action request context: " + request);
			}
		}
	}

	/**
	 * Processes the actual dispatching to the handler for render requests.
	 * <p>The handler will be obtained by applying the portlet's HandlerMappings in order.
	 * The HandlerAdapter will be obtained by querying the portlet's installed
	 * HandlerAdapters to find the first that supports the handler class.
	 * @param request current portlet render request
	 * @param response current portlet render response
	 * @throws Exception in case of any kind of processing failure
	 */
	protected void doRenderService(RenderRequest request, RenderResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received render request");
		}

		// Expose current LocaleResolver and request as LocaleContext.
		LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();
		LocaleContextHolder.setLocaleContext(buildLocaleContext(request), this.threadContextInheritable);

		// Expose current RequestAttributes to current thread.
		RequestAttributes previousRequestAttributes = RequestContextHolder.getRequestAttributes();
		PortletRequestAttributes requestAttributes = new PortletRequestAttributes(request);
		RequestContextHolder.setRequestAttributes(requestAttributes, this.threadContextInheritable);

		if (logger.isDebugEnabled()) {
			logger.debug("Bound render request context to thread: " + request);
		}

		RenderRequest processedRequest = request;
		HandlerExecutionChain mappedHandler = null;
		int interceptorIndex = -1;

		try {
			ModelAndView mv = null;
			try {
				// Check for forwarded exception from the action phase
				PortletSession session = request.getPortletSession(false);
				if (session != null) {
					if (request.getParameter(ACTION_EXCEPTION_RENDER_PARAMETER) != null) {
						Exception ex = (Exception) session.getAttribute(ACTION_EXCEPTION_SESSION_ATTRIBUTE);
						if (ex != null) {
							logger.debug("Render phase found exception caught during action phase - rethrowing it");
							throw ex;
						}
					}
					else {
						session.removeAttribute(ACTION_EXCEPTION_SESSION_ATTRIBUTE);
					}
				}
				
				// Determine handler for the current request.
				mappedHandler = getHandler(processedRequest, false);
				if (mappedHandler == null || mappedHandler.getHandler() == null) {
					noHandlerFound(processedRequest, response);
					return;
				}

				// Apply preHandle methods of registered interceptors.
				if (mappedHandler.getInterceptors() != null) {
					for (int i = 0; i < mappedHandler.getInterceptors().length; i++) {
						HandlerInterceptor interceptor = mappedHandler.getInterceptors()[i];
						if (!interceptor.preHandleRender(processedRequest, response, mappedHandler.getHandler())) {
							triggerAfterRenderCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);
							return;
						}
						interceptorIndex = i;
					}
				}

				// Actually invoke the handler.
				HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
				mv = ha.handleRender(processedRequest, response, mappedHandler.getHandler());

				// Apply postHandle methods of registered interceptors.
				if (mappedHandler.getInterceptors() != null) {
					for (int i = mappedHandler.getInterceptors().length - 1; i >= 0; i--) {
						HandlerInterceptor interceptor = mappedHandler.getInterceptors()[i];
						interceptor.postHandleRender(processedRequest, response, mappedHandler.getHandler(), mv);
					}
				}
			}
			catch (ModelAndViewDefiningException ex) {
				logger.debug("ModelAndViewDefiningException encountered", ex);
				mv = ex.getModelAndView();
			}
			catch (Exception ex) {
				Object handler = (mappedHandler != null ? mappedHandler.getHandler() : null);
				mv = processHandlerException(request, response, handler, ex);
			}

			// Did the handler return a view to render?
			if (mv != null && !mv.isEmpty()) {
				render(mv, processedRequest, response);
			}
			else {
				if (logger.isDebugEnabled()) {
					logger.debug("Null ModelAndView returned to DispatcherPortlet with name '" +
							getPortletName() + "': assuming HandlerAdapter completed request handling");
				}
			}

			// Trigger after-completion for successful outcome.
			triggerAfterRenderCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);
		}

		catch (Exception ex) {
			// Trigger after-completion for thrown exception.
			triggerAfterRenderCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
			throw ex;
		}
		catch (Error err) {
			PortletException ex =
					new PortletException("Error occured during request processing: " + err.getMessage(), err);
			// Trigger after-completion for thrown exception.
			triggerAfterRenderCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);
			throw ex;
		}

		finally {
			// Reset thread-bound context.
			RequestContextHolder.setRequestAttributes(previousRequestAttributes, this.threadContextInheritable);
			LocaleContextHolder.setLocaleContext(previousLocaleContext, this.threadContextInheritable);

			// Clear request attributes.
			requestAttributes.requestCompleted();
			if (logger.isDebugEnabled()) {
				logger.debug("Cleared thread-bound render request context: " + request);
			}
		}
	}


	/**
	 * Build a LocaleContext for the given request, exposing the request's
	 * primary locale as current locale.
	 * @param request current HTTP request