/*
* Copyright 2004-2012 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.webflow.mvc.portlet;
import java.util.Map;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.EventRequest;
import javax.portlet.EventResponse;
import javax.portlet.PortletModeException;
import javax.portlet.PortletRequest;
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 org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;
import org.springframework.web.portlet.HandlerAdapter;
import org.springframework.web.portlet.ModelAndView;
import org.springframework.web.portlet.handler.PortletContentGenerator;
import org.springframework.webflow.context.portlet.DefaultFlowUrlHandler;
import org.springframework.webflow.context.portlet.FlowUrlHandler;
import org.springframework.webflow.context.portlet.PortletExternalContext;
import org.springframework.webflow.core.FlowException;
import org.springframework.webflow.core.collection.LocalAttributeMap;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.execution.FlowExecutionOutcome;
import org.springframework.webflow.execution.repository.NoSuchFlowExecutionException;
import org.springframework.webflow.executor.FlowExecutionResult;
import org.springframework.webflow.executor.FlowExecutor;
/**
* A custom MVC HandlerAdapter that encapsulates the generic workflow associated with executing flows in a Portlet
* environment. Delegates to mapped {@link FlowHandler flow handlers} to manage the interaction with executions of
* specific flow definitions.
*
* @author Keith Donald
* @author Scott Andrews
* @author Rossen Stoyanchev
*/
public class FlowHandlerAdapter extends PortletContentGenerator implements HandlerAdapter, InitializingBean {
private static final String ACTION_REQUEST_FLOW_EXCEPTION_ATTRIBUTE = "actionRequestFlowException";
private FlowExecutor flowExecutor;
private FlowUrlHandler flowUrlHandler;
/**
* Creates a new flow handler adapter.
* @see #setFlowExecutor(FlowExecutor)
* @see #setFlowUrlHandler(FlowUrlHandler)
* @see #afterPropertiesSet()
*/
public FlowHandlerAdapter() {
// prevent caching of flow pages by default
setCacheSeconds(0);
}
/**
* Returns the central service for executing flows. Required.
*/
public FlowExecutor getFlowExecutor() {
return flowExecutor;
}
/**
* Sets the central service for executing flows. Required.
* @param flowExecutor
*/
public void setFlowExecutor(FlowExecutor flowExecutor) {
this.flowExecutor = flowExecutor;
}
/**
* Returns the flow url handler.
*/
public FlowUrlHandler getFlowUrlHandler() {
return flowUrlHandler;
}
/**
* Sets the flow url handler
* @param urlHandler the flow url handler
*/
public void setFlowUrlHandler(FlowUrlHandler urlHandler) {
this.flowUrlHandler = urlHandler;
}
public void afterPropertiesSet() throws Exception {
Assert.notNull(flowExecutor, "The FlowExecutor to execute flows is required");
if (flowUrlHandler == null) {
flowUrlHandler = new DefaultFlowUrlHandler();
}
}
public boolean supports(Object handler) {
return handler instanceof FlowHandler;
}
public ModelAndView handleRender(RenderRequest request, RenderResponse response, Object handler) throws Exception {
FlowHandler flowHandler = (FlowHandler) handler;
checkAndPrepare(request, response);
populateConveniencePortletProperties(request);
FlowException e = clearActionRequestFlowException(request, response, flowHandler);
if (e != null) {
return handleException(e, flowHandler, request, response);
}
String flowExecutionKey = flowUrlHandler.getFlowExecutionKey(request);
if (flowExecutionKey != null) {
return resumeFlowRender(request, response, flowHandler, flowExecutionKey);
} else {
MutableAttributeMap<Object> input = flowHandler.createExecutionInputMap(request);
if (input == null) {
input = defaultCreateFlowExecutionInputMap(request);
}
return startFlowRender(flowHandler, input, request, response);
}
}
public ModelAndView handleResource(ResourceRequest request, ResourceResponse response, Object handler)
throws Exception {
FlowHandler flowHandler = (FlowHandler) handler;
checkAndPrepare(request, response);
populateConveniencePortletProperties(request);
String flowExecutionKey = flowUrlHandler.getFlowExecutionKey(request);
if (flowExecutionKey != null) {
return resumeFlowResource(request, response, flowHandler, flowExecutionKey);
} else {
MutableAttributeMap<Object> input = flowHandler.createResourceExecutionInputMap(request);
if (input == null) {
input = defaultCreateFlowExecutionInputMap(request);
}
return startFlowResource(flowHandler, request, response);
}
}
public void handleAction(ActionRequest request, ActionResponse response, Object handler) throws Exception {
FlowHandler flowHandler = (FlowHandler) handler;
populateConveniencePortletProperties(request);
String flowExecutionKey = flowUrlHandler.getFlowExecutionKey(request);
PortletExternalContext context = createPortletExternalContext(request, response);
try {
FlowExecutionResult result = flowExecutor.resumeExecution(flowExecutionKey, context);
if (result.isPaused()) {
flowUrlHandler.setFlowExecutionRenderParameter(result.getPausedKey(), response);
} else if (result.isEnded()) {
handleFlowExecutionOutcome(result.getOutcome(), flowHandler, request, response);
} else {
throw new IllegalStateException("Execution result should have been one of [paused] or [ended]");
}
} catch (FlowException e) {
request.getPortletSession().setAttribute(ACTION_REQUEST_FLOW_EXCEPTION_ATTRIBUTE, e);
}
}
public void handleEvent(EventRequest request, EventResponse response, Object handler) throws Exception {
// keep render params
response.setRenderParameters(request);
}
// subclassing hooks
protected void populateConveniencePortletProperties(PortletRequest request) {
request.setAttribute("portletMode", request.getPortletMode().toString());
request.setAttribute("portletWindowState", request.getWindowState().toString());
}
protected PortletExternalContext createPortletExternalContext(PortletRequest request, PortletResponse response) {
return new PortletExternalContext(getPortletContext(), request, response);
}
protected MutableAttributeMap<Object> defaultCreateFlowExecutionInputMap(PortletRequest request) {
Map<String, String[]> parameterMap = request.getParameterMap();
if (parameterMap.size() == 0) {
return null;
}
LocalAttributeMap<Object> inputMap = new LocalAttributeMap<Object>();
for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
String[] values = entry.getValue();
inputMap.put(entry.getKey(), values.length == 1 ? values[0] : values);
}
return inputMap;
}
protected void defaultHandleExecutionOutcome(FlowExecutionOutcome outcome, FlowHandler flowHandler,
ActionRequest request, ActionResponse response) throws PortletModeException {
}
protected ModelAndView defaultHandleException(FlowHandler flowHandler, FlowException e, RenderRequest request,
RenderResponse response) {
if (e instanceof NoSuchFlowExecutionException) {
if (logger.isDebugEnabled()) {
logger.debug("Starting a new execution of previously ended flow '" + flowHandler.getFlowId() + "'");
}
// by default, attempt to restart the flow
try {
startFlowRender(flowHandler, null, request, response);
return null;
} catch (FlowException flowException) {
return handleException(flowException, flowHandler, request, response);
}
} else {
throw e;
}
}
protected ModelAndView defaultHandleResourceException(FlowHandler flowHandler, FlowException e,
ResourceRequest request, ResourceResponse response) {
if (e instanceof NoSuchFlowExecutionException) {
if (logger.isDebugEnabled()) {
logger.debug("Starting a new execution of previously ended flow '" + flowHandler.getFlowId() + "'");
}
// by default, attempt to restart the flow
return startFlowResource(flowHandler, request, response);
} else {
throw e;
}
}
// helpers
private ModelAndView handleException(FlowException e, FlowHandler flowHandler, RenderRequest request,
RenderResponse response) {
String view = flowHandler.handleException(e, request, response);
if (view != null) {
return new ModelAndView(view);
} else {
return defaultHandleException(flowHandler, e, request, response);
}
}
private ModelAndView handleResourceException(FlowException e, FlowHandler flowHandler, ResourceRequest request,
ResourceResponse response) {
String view = flowHandler.handleResourceException(e, request, response);
if (view != null) {
return new ModelAndView(view);
} else {
return defaultHandleResourceException(flowHandler, e, request, response);
}
}
private void handleFlowExecutionOutcome(FlowExecutionOutcome outcome, FlowHandler flowHandler,
ActionRequest request, ActionResponse response) throws PortletModeException {
boolean handled = flowHandler.handleExecutionOutcome(outcome, request, response);
if (!handled) {
defaultHandleExecutionOutcome(outcome, flowHandler, request, response);
}
}
private ModelAndView startFlowRender(FlowHandler flowHandler, MutableAttributeMap<Object> input,
RenderRequest request, RenderResponse response) {
PortletExternalContext context = createPortletExternalContext(request, response);
try {
FlowExecutionResult result = flowExecutor.launchExecution(flowHandler.getFlowId(), input, context);
if (result.isPaused()) {
flowUrlHandler.setFlowExecutionInSession(result.getPausedKey(), request);
}
return null;
} catch (FlowException flowEx) {
return handleException(flowEx, flowHandler, request, response);
}
}
private ModelAndView startFlowResource(FlowHandler flowHandler, ResourceRequest request, ResourceResponse response) {
PortletExternalContext context = createPortletExternalContext(request, response);
try {
FlowExecutionResult result = flowExecutor.launchExecution(flowHandler.getFlowId(), null, context);
if (result.isPaused()) {
flowUrlHandler.setFlowExecutionInSession(result.getPausedKey(), request);
}
return null;
} catch (FlowException flowEx) {
return handleResourceException(flowEx, flowHandler, request, response);
}
}
private ModelAndView resumeFlowRender(RenderRequest request, RenderResponse response, FlowHandler flowHandler,
String flowExecutionKey) {
PortletExternalContext context = createPortletExternalContext(request, response);
try {
flowExecutor.resumeExecution(flowExecutionKey, context);
return null;
} catch (FlowException e) {
return handleException(e, flowHandler, request, response);
}
}
private ModelAndView resumeFlowResource(ResourceRequest request, ResourceResponse response,
FlowHandler flowHandler, String flowExecutionKey) {
PortletExternalContext context = createPortletExternalContext(request, response);
try {
flowExecutor.resumeExecution(flowExecutionKey, context);
return null;
} catch (FlowException e) {
return handleResourceException(e, flowHandler, request, response);
}
}
private FlowException clearActionRequestFlowException(RenderRequest request, RenderResponse response,
FlowHandler flowHandler) {
PortletSession session = request.getPortletSession(false);
if (session != null) {
FlowException e = (FlowException) session.getAttribute(ACTION_REQUEST_FLOW_EXCEPTION_ATTRIBUTE);
if (e != null) {
session.removeAttribute(ACTION_REQUEST_FLOW_EXCEPTION_ATTRIBUTE);
return e;
}
}
return null;
}
}