/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.portlet;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.EventRequest;
import javax.portlet.EventResponse;
import javax.portlet.MimeResponse;
import javax.portlet.PortletException;
import javax.portlet.PortletRequest;
import javax.portlet.PortletRequestDispatcher;
import javax.portlet.PortletResponse;
import javax.portlet.PortletSession;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import javax.portlet.ResourceRequest;
import javax.portlet.ResourceResponse;
import javax.portlet.StateAwareResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.core.annotation.AnnotationAwareOrderComparator;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.core.style.StylerUtils;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.multipart.MultipartException;
import org.springframework.web.portlet.multipart.MultipartActionRequest;
import org.springframework.web.portlet.multipart.PortletMultipartResolver;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.ViewRendererServlet;
import org.springframework.web.servlet.ViewResolver;

/**
 * Central dispatcher for use within the Portlet MVC framework, e.g. for web UI
 * controllers. Dispatches to registered handlers for processing a portlet request.
 *
 * <p>This portlet is very flexible: It can be used with just about any workflow,
 * with the installation of the appropriate adapter classes. It offers the following
 * functionality that distinguishes it from other request-driven Portlet MVC frameworks:
 *
 * <ul>
 * <li>It is based around a JavaBeans configuration mechanism.
 *
 * <li>It can use any {@link HandlerMapping} implementation - pre-built or provided
 * as part of an application - to control the routing of requests to handler objects.
 * Default is a {@link org.springframework.web.portlet.mvc.annotation.DefaultAnnotationHandlerMapping}.
 * HandlerMapping objects can be defined as beans in the portlet's application context,
 * implementing the HandlerMapping interface, overriding the default HandlerMapping
 * if present. HandlerMappings can be given any bean name (they are tested by type).
 *
 * <li>It can use any {@link HandlerAdapter}; this allows for using any handler interface.
 * The default adapter is {@link org.springframework.web.portlet.mvc.SimpleControllerHandlerAdapter}
 * for Spring's {@link org.springframework.web.portlet.mvc.Controller} interface.
 * A default {@link org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter}
 * will be registered as well. HandlerAdapter objects can be added as beans in the
 * application context, overriding the default HandlerAdapter. Like HandlerMappings,
 * HandlerAdapters can be given any bean name (they are tested by type).
 *
 * <li>The dispatcher's exception resolution strategy can be specified via a
 * {@link HandlerExceptionResolver}, for example mapping certain exceptions to
 * error pages. Default is none. Additional HandlerExceptionResolvers can be added
 * through the application context. HandlerExceptionResolver can be given any
 * bean name (they are tested by type).
 *
 * <li>Its view resolution strategy can be specified via a {@link ViewResolver}
 * implementation, resolving symbolic view names into View objects. Default is
 * {@link org.springframework.web.servlet.view.InternalResourceViewResolver}.
 * ViewResolver objects can be added as beans in the application context,
 * overriding the default ViewResolver. ViewResolvers can be given any bean name
 * (they are tested by type).
 *
 * <li>The dispatcher's strategy for resolving multipart requests is determined by a
 * {@link org.springframework.web.portlet.multipart.PortletMultipartResolver}
 * implementation. An implementations for Apache Commons FileUpload is included:
 * {@link org.springframework.web.portlet.multipart.CommonsPortletMultipartResolver}.
 * The MultipartResolver bean name is "portletMultipartResolver"; default is none.
 * </ul>
 *
 * <p><b>NOTE: The {@code @RequestMapping} annotation will only be processed if a
 * corresponding {@code HandlerMapping} (for type-level annotations) and/or
 * {@code HandlerAdapter} (for method-level annotations) is present in the dispatcher.</b>
 * This is the case by default. However, if you are defining custom {@code HandlerMappings}
 * or {@code HandlerAdapters}, then you need to make sure that a corresponding custom
 * {@code DefaultAnnotationHandlerMapping} and/or {@code AnnotationMethodHandlerAdapter}
 * is defined as well - provided that you intend to use {@code @RequestMapping}.
 *
 * <p><b>A web application can define any number of DispatcherPortlets.</b>
 * Each portlet will operate in its own namespace, loading its own application context
 * with mappings, handlers, etc. Only the root application context as loaded by
 * {@link org.springframework.web.context.ContextLoaderListener}, if any, will be shared.
 *
 * <p>Thanks to Rainer Schmitz, Nick Lothian and Eric Dalquist for their suggestions!
 *
 * @author William G. Thompson, Jr.
 * @author John A. Lewis
 * @author Juergen Hoeller
 * @since 2.0
 * @see org.springframework.web.portlet.mvc.Controller
 * @see org.springframework.web.servlet.ViewRendererServlet
 * @see org.springframework.web.context.ContextLoaderListener
 */
public class DispatcherPortlet extends FrameworkPortlet {

	/**
	 * Well-known name for the PortletMultipartResolver object in the bean factory for this namespace.
	 */
	public static final String MULTIPART_RESOLVER_BEAN_NAME = "portletMultipartResolver";

	/**
	 * Well-known name for the HandlerMapping object in the bean factory for this namespace.
	 * Only used when "detectAllHandlerMappings" is turned off.
	 * @see #setDetectAllViewResolvers
	 */
	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 #setDetectAllViewResolvers
	 */
	public static final String HANDLER_EXCEPTION_RESOLVER_BEAN_NAME = "handlerExceptionResolver";

	/**
	 * Well-known name for the ViewResolver object in the bean factory for this namespace.
	 */
	public static final String VIEW_RESOLVER_BEAN_NAME = "viewResolver";

	/**
	 * Default URL to ViewRendererServlet. This bridge servlet is used to convert
	 * portlet render requests to servlet requests in order to leverage the view support
	 * in the {@code org.springframework.web.view} package.
	 */
	public static final String DEFAULT_VIEW_RENDERER_URL = "/WEB-INF/servlet/view";

	/**
	 * Unlike the Servlet version of this class, we have to deal with the
	 * two-phase nature of the portlet request. To do this, we need to pass
	 * forward any exception that occurs during the action phase, so that
	 * it can be displayed in the render phase. The only direct way to pass
	 * things forward and preserve them for each render request is through
	 * render parameters, but these are limited to String objects and we need
	 * to pass the Exception itself. The only other way to do this is in the
	 * session. The bad thing about using the session is that we have no way
	 * of knowing when we are done re-rendering the request and so we don't
	 * know when we can remove the objects from the session. So we will end
	 * up polluting the session with an old exception when we finally leave
	 * the render phase of one request and move on to something else.
	 */
	public static final String ACTION_EXCEPTION_SESSION_ATTRIBUTE =
			DispatcherPortlet.class.getName() + ".ACTION_EXCEPTION";

	/**
	 * This render parameter is used to indicate forward to the render phase
	 * that an exception occurred during the action phase.
	 */
	public static final String ACTION_EXCEPTION_RENDER_PARAMETER = "actionException";

	/**
	 * Log category to use when no mapped handler is found for a request.
	 */
	public static final String PAGE_NOT_FOUND_LOG_CATEGORY = "org.springframework.web.portlet.PageNotFound";

	/**
	 * Name of the class path resource (relative to the DispatcherPortlet class)
	 * that defines DispatcherPortet's default strategy names.
	 */
	private static final String DEFAULT_STRATEGIES_PATH = "DispatcherPortlet.properties";


	/**
	 * Additional logger to use when no mapped handler is found for a request.
	 */
	protected static final Log pageNotFoundLogger = LogFactory.getLog(PAGE_NOT_FOUND_LOG_CATEGORY);

	private static final Properties defaultStrategies;

	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, DispatcherPortlet.class);
			defaultStrategies = PropertiesLoaderUtils.loadProperties(resource);
		}
		catch (IOException ex) {
			throw new IllegalStateException("Could not load 'DispatcherPortlet.properties': " + ex.getMessage());
		}
	}


	/** 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;

	/** Whether exceptions thrown during doAction should be forwarded to doRender */
	private boolean forwardActionException = true;

	/** Whether exceptions thrown during doEvent should be forwarded to doRender */
	private boolean forwardEventException = false;

	/** URL that points to the ViewRendererServlet */
	private String viewRendererUrl = DEFAULT_VIEW_RENDERER_URL;


	/** MultipartResolver used by this portlet */
	private PortletMultipartResolver multipartResolver;

	/** List of HandlerMappings used by this portlet */
	private List<HandlerMapping> handlerMappings;

	/** List of HandlerAdapters used by this portlet */
	private List<HandlerAdapter> handlerAdapters;

	/** List of HandlerExceptionResolvers used by this portlet */
	private List<HandlerExceptionResolver> handlerExceptionResolvers;

	/** List of ViewResolvers used by this portlet */
	private List<ViewResolver> viewResolvers;


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

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

	/**
	 * 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 whether to forward exceptions thrown during the action phase
	 * to the render phase via a session attribute.
	 * <p>Default is true. Turn this off if you want the portlet container
	 * to provide immediate exception handling for action requests.
	 * @see #exposeActionException(javax.portlet.PortletRequest, javax.portlet.StateAwareResponse, Exception)
	 */
	public void setForwardActionException(boolean forwardActionException) {
		this.forwardActionException = forwardActionException;
	}

	/**
	 * Set whether to forward exceptions thrown during the event phase
	 * to the render phase via a session attribute.
	 * <p>Default is false. Turn this on if you want the {@link DispatcherPortlet}
	 * to forward the exception to the render phase, similar to what it does
	 * for {@link #setForwardActionException action exceptions} by default.
	 */
	public void setForwardEventException(boolean forwardEventException) {
		this.forwardEventException = forwardEventException;
	}

	/**
	 * 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;
	}


	/**
	 * This implementation calls {@link #initStrategies}.
	 */
	@Override
	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 = 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<String, HandlerMapping> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerMapping.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerMappings = new ArrayList<HandlerMapping>(matchingBeans.values());
				// We keep HandlerMappings in sorted order.
				AnnotationAwareOrderComparator.sort(this.handlerMappings);
			}
		}
		else {
			try {
				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.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<String, HandlerAdapter> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerAdapter.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerAdapters = new ArrayList<HandlerAdapter>(matchingBeans.values());
				// We keep HandlerAdapters in sorted order.
				AnnotationAwareOrderComparator.sort(this.handlerAdapters);
			}
		}
		else {
			try {
				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.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<String, HandlerExceptionResolver> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, HandlerExceptionResolver.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerExceptionResolvers = new ArrayList<HandlerExceptionResolver>(matchingBeans.values());
				// We keep HandlerExceptionResolvers in sorted order.
				AnnotationAwareOrderComparator.sort(this.handlerExceptionResolvers);
			}
		}
		else {
			try {
				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.
			}
		}

		// 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<String, ViewResolver> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(
					context, ViewResolver.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.viewResolvers = new ArrayList<ViewResolver>(matchingBeans.values());
				// We keep ViewResolvers in sorted order.
				AnnotationAwareOrderComparator.sort(this.viewResolvers);
			}
		}
		else {
			try {
				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.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
	 * @see #getDefaultStrategies
	 */
	protected <T> T getDefaultStrategy(ApplicationContext context, Class<T> strategyInterface) {
		List<T> 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
	 */
	@SuppressWarnings("unchecked")
	protected <T> List<T> getDefaultStrategies(ApplicationContext context, Class<T> strategyInterface) {
		String key = strategyInterface.getName();
		String value = defaultStrategies.getProperty(key);
		if (value != null) {
			String[] classNames = StringUtils.commaDelimitedListToStringArray(value);
			List<T> strategies = new ArrayList<T>(classNames.length);
			for (String className : classNames) {
				try {
					Class<?> clazz = ClassUtils.forName(className, DispatcherPortlet.class.getClassLoader());
					Object strategy = createDefaultStrategy(context, clazz);
					strategies.add((T) 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);
				}
			}
			return strategies;
		}
		else {
			return new LinkedList<T>();
		}
	}

	/**
	 * 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
	 * @see org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory()
	 */
	protected Object createDefaultStrategy(ApplicationContext context, Class<?> clazz) {
		return context.getAutowireCapableBeanFactory().createBean(clazz);
	}


	/**
	 * Obtain this portlet's PortletMultipartResolver, if any.
	 * @return the PortletMultipartResolver used by this portlet, or {@code null}
	 * 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
	 */
	@Override
	protected void doActionService(ActionRequest request, ActionResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received action request");
		}

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

		try {
			processedRequest = checkMultipart(request);

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

			// Apply preHandle methods of registered interceptors.
			HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();
			if (interceptors != null) {
				for (int i = 0; i < interceptors.length; i++) {
					HandlerInterceptor interceptor = interceptors[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.
			if (this.forwardActionException) {
				try {
					exposeActionException(request, response, ex);
					logger.debug("Caught exception during action phase - forwarding to render phase", ex);
				}
				catch (IllegalStateException ex2) {
					// Probably sendRedirect called... need to rethrow exception immediately.
					throw ex;
				}
			}
			else {
				throw ex;
			}
		}
		catch (Throwable 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);
			}
		}
	}

	/**
	 * 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
	 */
	@Override
	protected void doRenderService(RenderRequest request, RenderResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received render request");
		}

		HandlerExecutionChain mappedHandler = null;
		int interceptorIndex = -1;

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

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

				// 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);
					}
				}

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

				// Apply postHandle methods of registered interceptors.
				if (interceptors != null) {
					for (int i = interceptors.length - 1; i >= 0; i--) {
						HandlerInterceptor interceptor = interceptors[i];
						interceptor.postHandleRender(request, 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, request, 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, request, response, null);
		}

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

	/**
	 * Processes the actual dispatching to the handler for resource 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
	 */
	@Override
	protected void doResourceService(ResourceRequest request, ResourceResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received resource request");
		}

		HandlerExecutionChain mappedHandler = null;
		int interceptorIndex = -1;

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

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

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

				// Apply postHandle methods of registered interceptors.
				if (interceptors != null) {
					for (int i = interceptors.length - 1; i >= 0; i--) {
						HandlerInterceptor interceptor = interceptors[i];
						interceptor.postHandleResource(request, 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, request, 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.
			triggerAfterResourceCompletion(mappedHandler, interceptorIndex, request, response, null);
		}

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

	/**
	 * Processes the actual dispatching to the handler for event 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
	 */
	@Override
	protected void doEventService(EventRequest request, EventResponse response) throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("DispatcherPortlet with name '" + getPortletName() + "' received action request");
		}

		HandlerExecutionChain mappedHandler = null;
		int interceptorIndex = -1;

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

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

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

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

		catch (Exception ex) {
			// Trigger after-completion for thrown exception.
			triggerAfterEventCompletion(mappedHandler, interceptorIndex, request, response, ex);
			// Forward the exception to the render phase to be displayed.
			if (this.forwardEventException) {
				try {
					exposeActionException(request, response, ex);
					logger.debug("Caught exception during event phase - forwarding to render phase", ex);
				}
				catch (IllegalStateException ex2) {
					// Probably sendRedirect called... need to rethrow exception immediately.
					throw ex;
				}
			}
			else {
				throw ex;
			}
		}
		catch (Throwable err) {
			PortletException ex =
					new PortletException("Error occured during request processing: " + err.getMessage(), err);
			// Trigger after-completion for thrown exception.
			triggerAfterEventCompletion(mappedHandler, interceptorIndex, request, response, ex);
			throw ex;
		}
	}


	/**
	 * Convert the request into a multipart request, and make multipart resolver available.
	 * If no multipart resolver is set, simply use the existing request.
	 * @param request current HTTP request
	 * @return the processed request (multipart wrapper if necessary)
	 */
	protected ActionRequest checkMultipart(ActionRequest request) throws MultipartException {
		if (this.multipartResolver != null && this.multipartResolver.isMultipart(request)) {
			if (request instanceof MultipartActionRequest) {
				logger.debug("Request is already a MultipartActionRequest - probably in a forward");
			}
			else {
				return this.multipartResolver.resolveMultipart(request);
			}
		}
		// If not returned before: return original request.
		return request;
	}

	/**
	 * Return the HandlerExecutionChain for this request.
	 * Try all handler mappings in order.
	 * @param request current portlet request
	 * @return the HandlerExecutionChain, or null if no handler could be found
	 */
	protected HandlerExecutionChain getHandler(PortletRequest request) throws Exception {
		for (HandlerMapping hm : this.handlerMappings) {
			if (logger.isDebugEnabled()) {
				logger.debug(
						"Testing handler map [" + hm + "] in DispatcherPortlet with name '" + getPortletName() + "'");
			}
			HandlerExecutionChain handler = hm.getHandler(request);
			if (handler != null) {
				return handler;
			}
		}
		return null;
	}

	/**
	 * No handler found -> throw appropriate exception.
	 * @param request current portlet request
	 * @param response current portlet response
	 * @throws Exception if preparing the response failed
	 */
	protected void noHandlerFound(PortletRequest request, PortletResponse response) throws Exception {
		if (pageNotFoundLogger.isWarnEnabled()) {
			pageNotFoundLogger.warn("No handler found for current request " +
					"in DispatcherPortlet with name '" + getPortletName() +
					"', mode '" + request.getPortletMode() +
					"', phase '" + request.getAttribute(PortletRequest.LIFECYCLE_PHASE) +
					"', parameters " + StylerUtils.style(request.getParameterMap()));
		}
		throw new NoHandlerFoundException("No handler found for portlet request", request);
	}

	/**
	 * Return the HandlerAdapter for this handler object.
	 * @param handler the handler object to find an adapter for
	 * @throws PortletException if no HandlerAdapter can be found for the handler.
	 * This is a fatal error.
	 */
	protected HandlerAdapter getHandlerAdapter(Object handler) throws PortletException {
		for (HandlerAdapter ha : this.handlerAdapters) {
			if (logger.isDebugEnabled()) {
				logger.debug("Testing handler adapter [" + ha + "]");
			}
			if (ha.supports(handler)) {
				return ha;
			}
		}
		throw new PortletException("No adapter for handler [" + handler +
				"]: Does your handler implement a supported interface like Controller?");
	}

	/**
	 * Expose the given action exception to the given response.
	 * @param request current portlet request
	 * @param response current portlet response
	 * @param ex the action exception (may also come from an event phase)
	 */
	protected void exposeActionException(PortletRequest request, StateAwareResponse response, Exception ex) {
		// Copy all parameters unless overridden in the action handler.
		Enumeration<String> paramNames = request.getParameterNames();
		while (paramNames.hasMoreElements()) {
			String paramName = paramNames.nextElement();
			String[] paramValues = request.getParameterValues(paramName);
			if (paramValues != null && !response.getRenderParameterMap().containsKey(paramName)) {
				response.setRenderParameter(paramName, paramValues);
			}
		}
		response.setRenderParameter(ACTION_EXCEPTION_RENDER_PARAMETER, ex.toString());
		request.getPortletSession().setAttribute(ACTION_EXCEPTION_SESSION_ATTRIBUTE, ex);
	}


	/**
	 * Render the given ModelAndView. This is the last stage in handling a request.
	 * It may involve resolving the view by name.
	 * @param mv the ModelAndView to render
	 * @param request current portlet render request
	 * @param response current portlet render response
	 * @throws Exception if there's a problem rendering the view
	 */
	protected void render(ModelAndView mv, PortletRequest request, MimeResponse response) throws Exception {
		View view;
		if (mv.isReference()) {
			// We need to resolve the view name.
			view = resolveViewName(mv.getViewName(), mv.getModelInternal(), request);
			if (view == null) {
				throw new PortletException("Could not resolve view with name '" + mv.getViewName() +
						"' in portlet with name '" + getPortletName() + "'");
			}
		}
		else {
			// No need to lookup: the ModelAndView object contains the actual View object.
			Object viewObject = mv.getView();
			if (viewObject == null) {
				throw new PortletException("ModelAndView [" + mv + "] neither contains a view name nor a " +
						"View object in portlet with name '" + getPortletName() + "'");
			}
			if (!(viewObject instanceof View)) {
				throw new PortletException(
						"View object [" + viewObject + "] is not an instance of [org.springframework.web.servlet.View] - " +
						"DispatcherPortlet does not support any other view types");
			}
			view = (View) viewObject;
		}

		// Set the content type on the response if needed and if possible.
		// The Portlet spec requires the content type to be set on the RenderResponse;
		// it's not sufficient to let the View set it on the ServletResponse.
		if (response.getContentType() != null) {
			if (logger.isDebugEnabled()) {
				logger.debug("Portlet response content type already set to [" + response.getContentType() + "]");
			}
		}
		else {
			// No Portlet content type specified yet -> use the view-determined type.
			String contentType = view.getContentType();
			if (contentType != null) {
				if (logger.isDebugEnabled()) {
					logger.debug("Setting portlet response content type to view-determined type [" + contentType + "]");
				}
				response.setContentType(contentType);
			}
		}

		doRender(view, mv.getModelInternal(), request, response);
	}

	/**
	 * Resolve the given view name into a View object (to be rendered).
	 * <p>Default implementations asks all ViewResolvers of this dispatcher.
	 * Can be overridden for custom resolution strategies, potentially based
	 * on specific model attributes or request parameters.
	 * @param viewName the name of the view to resolve
	 * @param model the model to be passed to the view
	 * @param request current portlet render request
	 * @return the View object, or null if none found
	 * @throws Exception if the view cannot be resolved
	 * (typically in case of problems creating an actual View object)
	 * @see ViewResolver#resolveViewName
	 */
	protected View resolveViewName(String viewName, Map<String, ?> model, PortletRequest request) throws Exception {
		for (ViewResolver viewResolver : this.viewResolvers) {
			View view = viewResolver.resolveViewName(viewName, request.getLocale());
			if (view != null) {
				return view;
			}
		}
		return null;
	}

	/**
	 * Actually render the given view.
	 * <p>The default implementation delegates to
	 * {@link org.springframework.web.servlet.ViewRendererServlet}.
	 * @param view the View to render
	 * @param model the associated model
	 * @param request current portlet render/resource request
	 * @param response current portlet render/resource response
	 * @throws Exception if there's a problem rendering the view
	 */
	protected void doRender(View view, Map<String, ?> model, PortletRequest request, MimeResponse response) throws Exception {
		// Expose Portlet ApplicationContext to view objects.
		request.setAttribute(ViewRendererServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE, getPortletApplicationContext());

		// These attributes are required by the ViewRendererServlet.
		request.setAttribute(ViewRendererServlet.VIEW_ATTRIBUTE, view);
		request.setAttribute(ViewRendererServlet.MODEL_ATTRIBUTE, model);

		// Include the content of the view in the render/resource response.
		doDispatch(getPortletContext().getRequestDispatcher(this.viewRendererUrl), request, response);
	}

	/**
	 * Perform a dispatch on the given PortletRequestDispatcher.
	 * <p>The default implementation uses a forward for resource requests
	 * and an include for render requests.
	 * @param dispatcher the PortletRequestDispatcher to use
	 * @param request current portlet render/resource request
	 * @param response current portlet render/resource response
	 * @throws Exception if there's a problem performing the dispatch
	 */
	protected void doDispatch(PortletRequestDispatcher dispatcher, PortletRequest request, MimeResponse response)
			throws Exception {

		// In general, we prefer a forward for resource responses, in order to have full Servlet API
		// support in the target resource (e.g. on uPortal). However, on Liferay, a resource forward
		// displays an empty page, so we have to resort to an include there...
		if (PortletRequest.RESOURCE_PHASE.equals(request.getAttribute(PortletRequest.LIFECYCLE_PHASE)) &&
				!dispatcher.getClass().getName().startsWith("com.liferay")) {
			dispatcher.forward(request, response);
		}
		else {
			dispatcher.include(request, response);
		}
	}


	/**
	 * Determine an error ModelAndView via the registered HandlerExceptionResolvers.
	 * @param request current portlet request
	 * @param response current portlet response
	 * @param handler the executed handler, or null if none chosen at the time of
	 * the exception (for example, if multipart resolution failed)
	 * @param ex the exception that got thrown during handler execution
	 * @return a corresponding ModelAndView to forward to
	 * @throws Exception if no error ModelAndView found
	 */
	protected ModelAndView processHandlerException(
			RenderRequest request, RenderResponse response, Object handler, Exception ex)
			throws Exception {

		ModelAndView exMv = null;
		for (Iterator<HandlerExceptionResolver> it = this.handlerExceptionResolvers.iterator(); exMv == null && it.hasNext();) {
			HandlerExceptionResolver resolver = it.next();
			exMv = resolver.resolveException(request, response, handler, ex);
		}
		if (exMv != null) {
			if (logger.isDebugEnabled()) {
				logger.debug("HandlerExceptionResolver returned ModelAndView [" + exMv + "] for exception");
			}
			logger.warn("Handler execution resulted in exception - forwarding to resolved error view", ex);
			return exMv;
		}
		else {
			throw ex;
		}
	}

	/**
	 * Determine an error ModelAndView via the registered HandlerExceptionResolvers.
	 * @param request current portlet request
	 * @param response current portlet response
	 * @param handler the executed handler, or null if none chosen at the time of
	 * the exception (for example, if multipart resolution failed)
	 * @param ex the exception that got thrown during handler execution
	 * @return a corresponding ModelAndView to forward to
	 * @throws Exception if no error ModelAndView found
	 */
	protected ModelAndView processHandlerException(
			ResourceRequest request, ResourceResponse response, Object handler, Exception ex)
			throws Exception {

		ModelAndView exMv = null;
		for (Iterator<HandlerExceptionResolver> it = this.handlerExceptionResolvers.iterator(); exMv == null && it.hasNext();) {
			HandlerExceptionResolver resolver = it.next();
			exMv = resolver.resolveException(request, response, handler, ex);
		}
		if (exMv != null) {
			if (logger.isDebugEnabled()) {
				logger.debug("HandlerExceptionResolver returned ModelAndView [" + exMv + "] for exception");
			}
			logger.warn("Handler execution resulted in exception - forwarding to resolved error view", ex);
			return exMv;
		}
		else {
			throw ex;
		}
	}

	/**
	 * Trigger afterCompletion callbacks on the mapped HandlerInterceptors.
	 * Will just invoke afterCompletion for all interceptors whose preHandle
	 * invocation has successfully completed and returned true.
	 * @param mappedHandler the mapped HandlerExecutionChain
	 * @param interceptorIndex index of last interceptor that successfully completed
	 * @param ex Exception thrown on handler execution, or null if none
	 * @see HandlerInterceptor#afterRenderCompletion
	 */
	private void triggerAfterActionCompletion(HandlerExecutionChain mappedHandler, int interceptorIndex,
			ActionRequest request, ActionResponse response, Exception ex)
			throws Exception {

		// Apply afterCompletion methods of registered interceptors.
		if (mappedHandler != null) {
			HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();
			if (interceptors != null) {
				for (int i = interceptorIndex; i >= 0; i--) {
					HandlerInterceptor interceptor = interceptors[i];
					try {
						interceptor.afterActionCompletion(request, response, mappedHandler.getHandler(), ex);
					}
					catch (Throwable ex2) {
						logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
					}
				}
			}
		}
	}

	/**
	 * Trigger afterCompletion callbacks on the mapped HandlerInterceptors.
	 * Will just invoke afterCompletion for all interceptors whose preHandle
	 * invocation has successfully completed and returned true.
	 * @param mappedHandler the mapped HandlerExecutionChain
	 * @param interceptorIndex index of last interceptor that successfully completed
	 * @param ex Exception thrown on handler execution, or null if none
	 * @see HandlerInterceptor#afterRenderCompletion
	 */
	private void triggerAfterRenderCompletion(HandlerExecutionChain mappedHandler, int interceptorIndex,
			RenderRequest request, RenderResponse response, Exception ex)
			throws Exception {

		// Apply afterCompletion methods of registered interceptors.
		if (mappedHandler != null) {
			HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();
			if (interceptors != null) {
				for (int i = interceptorIndex; i >= 0; i--) {
					HandlerInterceptor interceptor = interceptors[i];
					try {
						interceptor.afterRenderCompletion(request, response, mappedHandler.getHandler(), ex);
					}
					catch (Throwable ex2) {
						logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
					}
				}
			}
		}
	}

	/**
	 * Trigger afterCompletion callbacks on the mapped HandlerInterceptors.
	 * Will just invoke afterCompletion for all interceptors whose preHandle
	 * invocation has successfully completed and returned true.
	 * @param mappedHandler the mapped HandlerExecutionChain
	 * @param interceptorIndex index of last interceptor that successfully completed
	 * @param ex Exception thrown on handler execution, or null if none
	 * @see HandlerInterceptor#afterRenderCompletion
	 */
	private void triggerAfterResourceCompletion(HandlerExecutionChain mappedHandler, int interceptorIndex,
			ResourceRequest request, ResourceResponse response, Exception ex)
			throws Exception {

		// Apply afterCompletion methods of registered interceptors.
		if (mappedHandler != null) {
			HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();
			if (interceptors != null) {
				for (int i = interceptorIndex; i >= 0; i--) {
					HandlerInterceptor interceptor = interceptors[i];
					try {
						interceptor.afterResourceCompletion(request, response, mappedHandler.getHandler(), ex);
					}
					catch (Throwable ex2) {
						logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
					}
				}
			}
		}
	}

	/**
	 * Trigger afterCompletion callbacks on the mapped HandlerInterceptors.
	 * Will just invoke afterCompletion for all interceptors whose preHandle
	 * invocation has successfully completed and returned true.
	 * @param mappedHandler the mapped HandlerExecutionChain
	 * @param interceptorIndex index of last interceptor that successfully completed
	 * @param ex Exception thrown on handler execution, or null if none
	 * @see HandlerInterceptor#afterRenderCompletion
	 */
	private void triggerAfterEventCompletion(HandlerExecutionChain mappedHandler, int interceptorIndex,
			EventRequest request, EventResponse response, Exception ex)
			throws Exception {

		// Apply afterCompletion methods of registered interceptors.
		if (mappedHandler != null) {
			HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();
			if (interceptors != null) {
				for (int i = interceptorIndex; i >= 0; i--) {
					HandlerInterceptor interceptor = interceptors[i];
					try {
						interceptor.afterEventCompletion(request, response, mappedHandler.getHandler(), ex);
					}
					catch (Throwable ex2) {
						logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
					}
				}
			}
		}
	}

}
