/*
* 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.config;
import java.util.Set;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.binding.convert.ConversionExecutor;
import org.springframework.binding.convert.ConversionService;
import org.springframework.binding.convert.service.DefaultConversionService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.webflow.conversation.ConversationManager;
import org.springframework.webflow.conversation.impl.SessionBindingConversationManager;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.core.collection.LocalAttributeMap;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.definition.registry.FlowDefinitionLocator;
import org.springframework.webflow.definition.registry.FlowDefinitionRegistry;
import org.springframework.webflow.engine.impl.FlowExecutionImplFactory;
import org.springframework.webflow.execution.FlowExecutionFactory;
import org.springframework.webflow.execution.factory.FlowExecutionListenerLoader;
import org.springframework.webflow.execution.repository.FlowExecutionRepository;
import org.springframework.webflow.execution.repository.impl.DefaultFlowExecutionRepository;
import org.springframework.webflow.execution.repository.snapshot.FlowExecutionSnapshotFactory;
import org.springframework.webflow.execution.repository.snapshot.SerializedFlowExecutionSnapshotFactory;
import org.springframework.webflow.execution.repository.snapshot.SimpleFlowExecutionSnapshotFactory;
import org.springframework.webflow.executor.FlowExecutor;
import org.springframework.webflow.executor.FlowExecutorImpl;
import org.springframework.webflow.mvc.builder.MvcEnvironment;
/**
* This factory encapsulates the construction and assembly of a {@link FlowExecutor}, including the provision of its
* {@link FlowExecutionRepository} strategy. As a <code>FactoryBean</code>, this class has been designed for use as a
* Spring managed bean.
* <p>
* The definition locator property is required, all other properties are optional.
*
* @author Keith Donald
* @author Erwin Vervaet
*/
class FlowExecutorFactoryBean implements FactoryBean<FlowExecutor>, ApplicationContextAware, BeanClassLoaderAware,
InitializingBean {
private static final String ALWAYS_REDIRECT_ON_PAUSE = "alwaysRedirectOnPause";
private static final String REDIRECT_IN_SAME_STATE = "redirectInSameState";
private FlowDefinitionLocator flowDefinitionLocator;
private Integer maxFlowExecutions;
private Integer maxFlowExecutionSnapshots;
private Set<FlowElementAttribute> flowExecutionAttributes;
private FlowExecutionListenerLoader flowExecutionListenerLoader;
private ConversationManager conversationManager;
private ConversionService conversionService;
private FlowExecutor flowExecutor;
private MvcEnvironment environment;
private ClassLoader classLoader;
/**
* Sets the flow definition locator that will locate flow definitions needed for execution. Typically also a
* {@link FlowDefinitionRegistry}. Required.
* @param flowDefinitionLocator the flow definition locator (registry)
*/
public void setFlowDefinitionLocator(FlowDefinitionLocator flowDefinitionLocator) {
this.flowDefinitionLocator = flowDefinitionLocator;
}
/**
* Set the maximum number of allowed flow executions allowed per user.
*/
public void setMaxFlowExecutions(int maxFlowExecutions) {
this.maxFlowExecutions = maxFlowExecutions;
}
/**
* Set the maximum number of history snapshots allowed per flow execution.
*/
public void setMaxFlowExecutionSnapshots(int maxFlowExecutionSnapshots) {
this.maxFlowExecutionSnapshots = maxFlowExecutionSnapshots;
}
/**
* Sets the system attributes that apply to flow executions launched by the executor created by this factory.
* Execution attributes may affect flow execution behavior.
* @param flowExecutionAttributes the flow execution system attributes
*/
public void setFlowExecutionAttributes(Set<FlowElementAttribute> flowExecutionAttributes) {
this.flowExecutionAttributes = flowExecutionAttributes;
}
/**
* Sets the strategy for loading the listeners that will observe executions of a flow definition. Allows full
* control over what listeners should apply to executions of a flow definition launched by the executor created by
* this factory.
*/
public void setFlowExecutionListenerLoader(FlowExecutionListenerLoader flowExecutionListenerLoader) {
this.flowExecutionListenerLoader = flowExecutionListenerLoader;
}
/**
* Sets the service type that manages conversations and effectively controls how state is stored physically when a
* flow execution is paused.
*/
public void setConversationManager(ConversationManager conversationManager) {
this.conversationManager = conversationManager;
}
// implementing ApplicationContextAware
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
environment = MvcEnvironment.environmentFor(applicationContext);
}
// implement BeanClassLoaderAware
public void setBeanClassLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}
// implementing InitializingBean
public void afterPropertiesSet() throws Exception {
Assert.notNull(flowDefinitionLocator, "The flow definition locator property is required");
if (conversionService == null) {
conversionService = new DefaultConversionService();
}
MutableAttributeMap<Object> executionAttributes = createFlowExecutionAttributes();
FlowExecutionImplFactory executionFactory = createFlowExecutionFactory(executionAttributes);
DefaultFlowExecutionRepository executionRepository = createFlowExecutionRepository(executionFactory);
executionFactory.setExecutionKeyFactory(executionRepository);
flowExecutor = new FlowExecutorImpl(flowDefinitionLocator, executionFactory, executionRepository);
}
// implementing FactoryBean
public Class<?> getObjectType() {
return FlowExecutor.class;
}
public boolean isSingleton() {
return true;
}
public FlowExecutor getObject() throws Exception {
return flowExecutor;
}
private MutableAttributeMap<Object> createFlowExecutionAttributes() {
LocalAttributeMap<Object> executionAttributes = new LocalAttributeMap<Object>();
if (flowExecutionAttributes != null) {
for (FlowElementAttribute attribute : flowExecutionAttributes) {
executionAttributes.put(attribute.getName(), getConvertedValue(attribute));
}
}
putDefaultFlowExecutionAttributes(executionAttributes);
return executionAttributes;
}
private void putDefaultFlowExecutionAttributes(LocalAttributeMap<Object> executionAttributes) {
if (!executionAttributes.contains(ALWAYS_REDIRECT_ON_PAUSE)) {
Boolean redirect = (environment != MvcEnvironment.PORTLET);
executionAttributes.put(ALWAYS_REDIRECT_ON_PAUSE, redirect);
}
if (!executionAttributes.contains(REDIRECT_IN_SAME_STATE)) {
Boolean redirect = (environment != MvcEnvironment.PORTLET);
executionAttributes.put(REDIRECT_IN_SAME_STATE, redirect);
}
}
private DefaultFlowExecutionRepository createFlowExecutionRepository(FlowExecutionFactory executionFactory) {
ConversationManager conversationManager = createConversationManager();
FlowExecutionSnapshotFactory snapshotFactory = createFlowExecutionSnapshotFactory(executionFactory);
DefaultFlowExecutionRepository rep = new DefaultFlowExecutionRepository(conversationManager, snapshotFactory);
if (maxFlowExecutionSnapshots != null) {
rep.setMaxSnapshots(maxFlowExecutionSnapshots);
}
return rep;
}
private ConversationManager createConversationManager() {
if (conversationManager == null) {
conversationManager = new SessionBindingConversationManager();
if (maxFlowExecutions != null) {
((SessionBindingConversationManager) conversationManager).setMaxConversations(maxFlowExecutions);
}
}
return this.conversationManager;
}
private FlowExecutionSnapshotFactory createFlowExecutionSnapshotFactory(FlowExecutionFactory executionFactory) {
if (maxFlowExecutionSnapshots != null && maxFlowExecutionSnapshots == 0) {
maxFlowExecutionSnapshots = 1;
return new SimpleFlowExecutionSnapshotFactory(executionFactory, flowDefinitionLocator);
} else {
return new SerializedFlowExecutionSnapshotFactory(executionFactory, flowDefinitionLocator);
}
}
private FlowExecutionImplFactory createFlowExecutionFactory(AttributeMap<Object> executionAttributes) {
FlowExecutionImplFactory executionFactory = new FlowExecutionImplFactory();
executionFactory.setExecutionAttributes(executionAttributes);
if (flowExecutionListenerLoader != null) {
executionFactory.setExecutionListenerLoader(flowExecutionListenerLoader);
}
return executionFactory;
}
// utility methods
private Object getConvertedValue(FlowElementAttribute attribute) {
if (attribute.needsTypeConversion()) {
Class<?> targetType = fromStringToClass(attribute.getType());
ConversionExecutor converter = conversionService.getConversionExecutor(String.class, targetType);
return converter.execute(attribute.getValue());
} else {
return attribute.getValue();
}
}
private Class<?> fromStringToClass(String name) {
Class<?> clazz = conversionService.getClassForAlias(name);
if (clazz != null) {
return clazz;
} else {
try {
return ClassUtils.forName(name, classLoader);
} catch (ClassNotFoundException e) {
throw new IllegalArgumentException("Unable to load class '" + name + "'");
}
}
}
}