dispatcherportlet.java

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

	/**
	 * Set whether to detect all HandlerExceptionResolver beans in this portlet's context.
	 * Else, just a single bean with name "handlerExceptionResolver" will be expected.
	 * <p>Default is true. Turn this off if you want this portlet to use a
	 * single HandlerExceptionResolver, despite multiple HandlerExceptionResolver
	 * beans being defined in the context.
	 */
	public void setDetectAllHandlerExceptionResolvers(boolean detectAllHandlerExceptionResolvers) {
		this.detectAllHandlerExceptionResolvers = detectAllHandlerExceptionResolvers;
	}

	/**
	 * Set whether to detect all ViewResolver beans in this portlet's context.
	 * Else, just a single bean with name "viewResolver" will be expected.
	 * <p>Default is true. Turn this off if you want this portlet to use a
	 * single ViewResolver, despite multiple ViewResolver beans being
	 * defined in the context.
	 */
	public void setDetectAllViewResolvers(boolean detectAllViewResolvers) {
		this.detectAllViewResolvers = detectAllViewResolvers;
	}

	/**
	 * Set the URL to the ViewRendererServlet. That servlet is used to
	 * ultimately render all views in the portlet application.
	 */
	public void setViewRendererUrl(String viewRendererUrl) {
		this.viewRendererUrl = viewRendererUrl;
	}

	/**
	 * Set whether to expose the LocaleContext and RequestAttributes as inheritable
	 * for child threads (using an {@link java.lang.InheritableThreadLocal}).
	 * <p>Default is "false", to avoid side effects on spawned background threads.
	 * Switch this to "true" to enable inheritance for custom child threads which
	 * are spawned during request processing and only used for this request
	 * (that is, ending after their initial task, without reuse of the thread).
	 * <p><b>WARNING:</b> Do not use inheritance for child threads if you are
	 * accessing a thread pool which is configured to potentially add new threads
	 * on demand (e.g. a JDK {@link java.util.concurrent.ThreadPoolExecutor}),
	 * since this will expose the inherited context to such a pooled thread.
	 */
	public void setThreadContextInheritable(boolean threadContextInheritable) {
		this.threadContextInheritable = threadContextInheritable;
	}


	/**
	 * This implementation calls {@link #initStrategies}.
	 */
	public void onRefresh(ApplicationContext context) {
		initStrategies(context);
	}

	/**
	 * Refresh the strategy objects that this portlet uses.
	 * <p>May be overridden in subclasses in order to initialize
	 * further strategy objects.
	 */
	protected void initStrategies(ApplicationContext context) {
		initMultipartResolver(context);
		initHandlerMappings(context);
		initHandlerAdapters(context);
		initHandlerExceptionResolvers(context);
		initViewResolvers(context);
	}

	/**
	 * Initialize the PortletMultipartResolver used by this class.
	 * <p>If no valid bean is defined with the given name in the BeanFactory
	 * for this namespace, no multipart handling is provided.
	 */
	private void initMultipartResolver(ApplicationContext context) {
		try {
			this.multipartResolver = (PortletMultipartResolver)
					context.getBean(MULTIPART_RESOLVER_BEAN_NAME, PortletMultipartResolver.class);
			if (logger.isDebugEnabled()) {
				logger.debug("Using MultipartResolver [" + this.multipartResolver + "]");
			}
		}
		catch (NoSuchBeanDefinitionException ex) {
			// Default is no multipart resolver.
			this.multipartResolver = null;
			if (logger.isDebugEnabled()) {
				logger.debug("Unable to locate PortletMultipartResolver with name '"	+ MULTIPART_RESOLVER_BEAN_NAME +
						"': no multipart request handling provided");
			}
		}
	}

	/**
	 * Initialize the HandlerMappings used by this class.
	 * <p>If no HandlerMapping beans are defined in the BeanFactory
	 * for this namespace, we default to PortletModeHandlerMapping.
	 */
	private void initHandlerMappings(ApplicationContext context) {
		this.handlerMappings = null;

		if (this.detectAllHandlerMappings) {
			// Find all HandlerMappings in the ApplicationContext,
			// including ancestor contexts.
			Map matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerMapping.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerMappings = new ArrayList(matchingBeans.values());
				// We keep HandlerMappings in sorted order.
				Collections.sort(this.handlerMappings, new OrderComparator());
			}
		}
		else {
			try {
				Object 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.isDebugEnabled()) {
				logger.debug("No HandlerMappings found in portlet '" + getPortletName() + "': using default");
			}
		}
	}

	/**
	 * Initialize the HandlerAdapters used by this class.
	 * <p>If no HandlerAdapter beans are defined in the BeanFactory
	 * for this namespace, we default to SimpleControllerHandlerAdapter.
	 */
	private void initHandlerAdapters(ApplicationContext context) {
		this.handlerAdapters = null;

		if (this.detectAllHandlerAdapters) {
			// Find all HandlerAdapters in the ApplicationContext,
			// including ancestor contexts.
			Map matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerAdapter.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerAdapters = new ArrayList(matchingBeans.values());
				// We keep HandlerAdapters in sorted order.
				Collections.sort(this.handlerAdapters, new OrderComparator());
			}
		}
		else {
			try {
				Object 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.isDebugEnabled()) {
				logger.debug("No HandlerAdapters found in portlet '" + getPortletName() + "': using default");
			}
		}
	}

	/**
	 * Initialize the HandlerExceptionResolver used by this class.
	 * <p>If no bean is defined with the given name in the BeanFactory
	 * for this namespace, we default to no exception resolver.
	 */
	private void initHandlerExceptionResolvers(ApplicationContext context) {
		this.handlerExceptionResolvers = null;

		if (this.detectAllHandlerExceptionResolvers) {
			// Find all HandlerExceptionResolvers in the ApplicationContext,
			// including ancestor contexts.
			Map matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerExceptionResolver.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerExceptionResolvers = new ArrayList(matchingBeans.values());
				// We keep HandlerExceptionResolvers in sorted order.
				Collections.sort(this.handlerExceptionResolvers, new OrderComparator());
			}
		}
		else {
			try {
				Object her = context.getBean(
						HANDLER_EXCEPTION_RESOLVER_BEAN_NAME, HandlerExceptionResolver.class);
				this.handlerExceptionResolvers = Collections.singletonList(her);
			}
			catch (NoSuchBeanDefinitionException ex) {
				// Ignore, no HandlerExceptionResolver is fine too.
			}
		}

		// Just for consistency, check for default HandlerExceptionResolvers...
		// There aren't any in usual scenarios.
		if (this.handlerExceptionResolvers == null) {
			this.handlerExceptionResolvers = getDefaultStrategies(context, HandlerExceptionResolver.class);
			if (logger.isDebugEnabled()) {
				logger.debug("No HandlerExceptionResolvers found in portlet '" + getPortletName() + "': using default");
			}
		}
	}

	/**
	 * Initialize the ViewResolvers used by this class.
	 * <p>If no ViewResolver beans are defined in the BeanFactory
	 * for this namespace, we default to InternalResourceViewResolver.
	 */
	private void initViewResolvers(ApplicationContext context) {
		this.viewResolvers = null;

		if (this.detectAllViewResolvers) {
			// Find all ViewResolvers in the ApplicationContext,
			// including ancestor contexts.
			Map matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, ViewResolver.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.viewResolvers = new ArrayList(matchingBeans.values());
				// We keep ViewResolvers in sorted order.
				Collections.sort(this.viewResolvers, new OrderComparator());
			}
		}
		else {
			try {
				Object 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.isDebugEnabled()) {
				logger.debug("No ViewResolvers found in portlet '" + getPortletName() + "': using default");
			}
		}
	}


	/**
	 * Return the default strategy object for the given strategy interface.
	 * <p>The default implementation delegates to {@link #getDefaultStrategies},
	 * expecting a single object in the list.
	 * @param context the current Portlet ApplicationContext
	 * @param strategyInterface the strategy interface
	 * @return the corresponding strategy object
	 * @throws BeansException if initialization failed
	 * @see #getDefaultStrategies
	 */
	protected Object getDefaultStrategy(ApplicationContext context, Class strategyInterface) throws BeansException {
		List strategies = getDefaultStrategies(context, strategyInterface);
		if (strategies.size() != 1) {
			throw new BeanInitializationException(
					"DispatcherPortlet needs exactly 1 strategy for interface [" + strategyInterface.getName() + "]");
		}
		return strategies.get(0);
	}

	/**
	 * Create a List of default strategy objects for the given strategy interface.
	 * <p>The default implementation uses the "DispatcherPortlet.properties" file
	 * (in the same package as the DispatcherPortlet class) to determine the class names.
	 * It instantiates the strategy objects and satisifies ApplicationContextAware
	 * if necessary.
	 * @param context the current Portlet ApplicationContext
	 * @param strategyInterface the strategy interface
	 * @return the List of corresponding strategy objects
	 * @throws BeansException if initialization failed
	 */
	protected List getDefaultStrategies(ApplicationContext context, Class strategyInterface) throws BeansException {
		String key = strategyInterface.getName();
		List strategies = null;
		String value = defaultStrategies.getProperty(key);
		if (value != null) {