Java tutorial
/** * Copyright (C) 2008 Maurice Zeijen <maurice@zeijen.net> * * 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.milyn.smooks.mule.core; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.commons.lang.StringUtils; import org.milyn.SmooksException; import org.milyn.cdr.Parameter; import org.milyn.cdr.SmooksConfigurationException; import org.milyn.cdr.SmooksResourceConfiguration; import org.milyn.cdr.annotation.AnnotationConstants; import org.milyn.cdr.annotation.AppContext; import org.milyn.cdr.annotation.Config; import org.milyn.cdr.annotation.ConfigParam; import org.milyn.cdr.annotation.ConfigParam.Use; import org.milyn.container.ApplicationContext; import org.milyn.container.ExecutionContext; import org.milyn.delivery.annotation.Initialize; import org.milyn.delivery.annotation.VisitAfterIf; import org.milyn.delivery.annotation.VisitBeforeIf; import org.milyn.delivery.dom.DOMElementVisitor; import org.milyn.delivery.ordering.Consumer; import org.milyn.delivery.ordering.Producer; import org.milyn.delivery.sax.SAXElement; import org.milyn.delivery.sax.SAXVisitAfter; import org.milyn.delivery.sax.SAXVisitBefore; import org.milyn.event.report.annotation.VisitAfterReport; import org.milyn.event.report.annotation.VisitBeforeReport; import org.milyn.expression.MVELExpressionEvaluator; import org.milyn.javabean.DataDecodeException; import org.milyn.javabean.DataDecoder; import org.milyn.javabean.context.BeanContext; import org.milyn.javabean.context.BeanIdStore; import org.milyn.javabean.repository.BeanId; import org.milyn.smooks.mule.core.message.MVELEvaluatingMessagePropertyValue; import org.milyn.smooks.mule.core.message.MessageProperty; import org.milyn.smooks.mule.core.message.MessagePropertyValue; import org.milyn.smooks.mule.core.message.StaticMessagePropertyValue; import org.milyn.util.CollectionsUtil; import org.milyn.xml.DomUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.w3c.dom.Element; import org.w3c.dom.NodeList; /** * The MuleDispatcher is a Smooks Resource visitor to dispatch message * parts to endpoints in Mule. * <p/> * <h3>Usage:</h3> * A MuleDispatcher is defined as follows: * <pre> * <resource-config selector="order"> * <resource>org.milyn.smooks.mule.MuleDispatcher</resource> * <param name="endpointName">order</param> * <param name="beanId">order</param> * </resource-config> * </pre> * * <b>Required parameters:</b> * <property name="endpointName" value="someEndpoint" /> * * <b>Optional parameters:</b> * <param name="beanId">someBeanId</param> * <param name="resultBeanId">someBeanIdToBindTheResultTo</param> * <param name="messagePropertiesBeanId">someBeanIdToGetTheMessagePropertiesFrom</param> * <param name="messageProperties" > * <property name="somePropertyName" value="somePropertyValue" type="someType" /> * </param> * </pre> * * <h3>Description of configuration parameters</h3> * <ul> * <li><i>endpointName</i> - The name of the endpoint which will be used when routing the message. If no endpoint can be found under that name then an exception is thrown. * <li><i>expression</i> - A MVEL script. The result of the script is used as the message payload. This overrides the beanId property. * <li><i>beanId</i> - The bean id of the bean which will be used as the message payload. The context of the MVEL script contains all the beans of the bean map. * <li><i>resultBeanId</i> - If the endpoint returns a result then the payload of that result is bounded to the resultBeanId. * When the resultBeanId isn't set then the result is discarded. If the resultBeanId is set then the * endpoint is forced to distpatch synchronous. * <li><i>messagePropertiesBeanId</i> - * <li><i>messageProperties</i> - Properties that will be set on the message before dispatching. * The MuleDispatcher messageProperties attribute section explains how to set the message properties * </ul> * * <h3>MuleDispatcher messageProperties attribute</h3> * Message properties are defined as folows: * <pre> * <resource-config selector="order"> * <resource>org.milyn.smooks.mule.MuleDispatcher</resource> * <param name="endpointName">testEndpoint</param> * <param name="messageBeanId">test</param> * <param name="messageProperties"> * <property name="prop1" value="prop1Value" /> * <property name="prop2">"prop2Value"</property> * <property name="intProp" value="10" type="Integer" /> * <property name="dateProp" value="2008-07-11 12:30:56" type="DateTime" /> * </param> * </resource-config> * * <resource-config selector="decoder:DateTime"> * <resource>org.milyn.javabean.decoders.DateDecoder</resource> * <param name="format">yyyy-MM-dd HH:mm:ss</param> * </resource-config> * </pre> * * The following points explain the four properties: * <ol> * <li>The first property uses a attribute to set the value. * <li>The second property takes the property element content and parses it as a MVEL expression. * <li>The third property uses the type attribute to define a Integer type. This will convert the value into an Integer. This uses the standard DataDecoder feature from Smooks. * <li>The fourth property uses the type attribute to define a custom configured Date type. This will convert the value into a Date. The configuration is set in the resource-config with the "decoder:DateTime" selector. This uses the standard DataDecoder feature from Smooks. * </ol> * * <h3>Description of property attributes</h3> * <ul> * <li><i>name</i> - The message property name (required) * <li><i>value</i> - The value of the property. The property element content can also be set. If both are set then the value attribute is used. * <li><i>type</i> - The type of the property value. This uses the standard DataDecoder feature from Smooks. DataDecoders can be configured using * a "decoder:decoderName" resource-config selector. The decoderName must be set as type then. (Default: String) * </ul> * * <h3>Description of the property element content</h3> * The property element content is parsed as a MVEL expression. This gives * great flexibility. The MVEL context contains all the beans from the bean map. * The type and value attribute are ignored when the element content is set. * * @author <a href="mailto:maurice@zeijen.net">Maurice Zeijen</a> */ @VisitBeforeIf(condition = "parameters.containsKey('executeBefore') && parameters.executeBefore.value == 'true'") @VisitAfterIf(condition = "!parameters.containsKey('executeBefore') || parameters.executeBefore.value != 'true'") @VisitBeforeReport(summary = "Dispatch to endpoint '${resource.parameters.endpointName}'.", detailTemplate = "reporting/MuleDispatcher.html") @VisitAfterReport(summary = "Dispatch to endpoint '${resource.parameters.endpointName}'.", detailTemplate = "reporting/MuleDispatcher.html") public class MuleDispatcher implements DOMElementVisitor, SAXVisitBefore, SAXVisitAfter, Consumer, Producer { private static final String MESSAGE_PROPERTIES_PARAMETER_TYPE = "type"; private static final String MESSAGE_PROPERTIES_PARAMETER_VALUE = "value"; private static final String MESSAGE_PROPERTIES_PARAMETER_DECODER = "decoder"; private static final String MESSAGE_PROPERTIES_ATTRIBUTE_NAME = "name"; private static final String MESSAGE_PROPERTIES_NODE_NAME = "property"; private static final String MESSAGE_EXPRESSION_NODE_NAME = "expression"; public static final String PARAMETER_MESSAGE_PROPERTIES = "messageProperties"; private static final Logger log = LoggerFactory.getLogger(MuleDispatcher.class); @ConfigParam(use = Use.REQUIRED) private String endpointName; @ConfigParam(name = "beanId", use = Use.OPTIONAL) private String beanIdName; private BeanId beanId; @ConfigParam(name = "resultBeanId", use = Use.OPTIONAL) private String resultBeanIdName; private BeanId resultBeanId; @ConfigParam(name = "messagePropertiesBeanId", use = Use.OPTIONAL) private String messagePropertiesBeanIdName; private BeanId messagePropertiesBeanId; @ConfigParam(defaultVal = AnnotationConstants.NULL_STRING) private MVELExpressionEvaluator expression; private List<MessageProperty> staticMessageProperties; @ConfigParam(defaultVal = "false") private boolean copyOriginalMessageProperties; @ConfigParam(defaultVal = "true") private boolean overrideOriginalMessageProperties; @ConfigParam(defaultVal = "true") private boolean ignorePropertiesWithNullValues; @ConfigParam(defaultVal = "false") private boolean copyOriginalMessageAttachments; @Config private SmooksResourceConfiguration config; @AppContext private ApplicationContext appContext; @Initialize public void initialize() { BeanIdStore beanIdStore = appContext.getBeanIdStore(); if (beanIdName != null) { beanId = beanIdStore.register(beanIdName); } if (resultBeanIdName != null) { resultBeanId = beanIdStore.register(resultBeanIdName); } if (messagePropertiesBeanIdName != null) { messagePropertiesBeanId = beanIdStore.register(messagePropertiesBeanIdName); } } /** * {@inheritDoc} */ public void visitBefore(Element element, ExecutionContext executionContext) throws SmooksException { dispatch(executionContext); } /** * {@inheritDoc} */ public void visitBefore(SAXElement element, ExecutionContext executionContext) throws SmooksException, IOException { dispatch(executionContext); } /** * {@inheritDoc} */ public void visitAfter(Element element, ExecutionContext executionContext) throws SmooksException { dispatch(executionContext); } /** * {@inheritDoc} */ public void visitAfter(SAXElement element, ExecutionContext executionContext) throws SmooksException, IOException { dispatch(executionContext); } /** * Dispatches a message to an endpoint * * @param executionContext */ private void dispatch(ExecutionContext executionContext) { Object payload = null; BeanContext beanRepository = executionContext.getBeanContext(); if (expression != null) { Map<?, ?> beanMap = beanRepository.getBeanMap(); payload = expression.getValue(beanMap); } else if (beanIdName != null) { payload = beanRepository.getBean(beanId); } if (log.isInfoEnabled()) { String payloadMsg; if (payload == null) { payloadMsg = " with no payload"; } else { payloadMsg = " with a " + payload.getClass().getName() + " payload"; if (expression != null) { payloadMsg += " from an expression"; } else { payloadMsg += " from beanId '" + beanIdName + "'"; } } log.info("Dispatching Mule message to endpoint '" + endpointName + "'" + payloadMsg); } NamedEndpointMuleDispatcher dispatcher = (NamedEndpointMuleDispatcher) executionContext .getAttribute(NamedEndpointMuleDispatcher.SMOOKS_CONTEXT); if (dispatcher == null) { throw new IllegalStateException( "The executionContext doesn't have the MuleDispatcher object as the attribute with the key '" + NamedEndpointMuleDispatcher.SMOOKS_CONTEXT + "'"); } boolean forceSynchronous = resultBeanId != null; Map<String, Object> messageProperties = createMessagePropertiesMap(executionContext); Object result = dispatcher.dispatch(endpointName, payload, messageProperties, forceSynchronous, copyOriginalMessageProperties, overrideOriginalMessageProperties, ignorePropertiesWithNullValues, copyOriginalMessageAttachments); if (result != null && resultBeanId != null) { if (log.isInfoEnabled()) { log.info("Received result from endpoint '" + endpointName + "'. Adding it to the bean map under beanId '" + resultBeanId.getName() + "'"); } beanRepository.addBean(resultBeanId, result); } } /** * Creates the message properties map from the static message properties and the possible * properties from the Map found under the messageProperties bean Id. * * @param executionContext * @return */ @SuppressWarnings("unchecked") private Map<String, Object> createMessagePropertiesMap(ExecutionContext executionContext) { HashMap<String, Object> props = evaluateStaticMessageProperties(executionContext); if (messagePropertiesBeanId != null) { BeanContext beanContext = executionContext.getBeanContext(); Map<String, Object> bProperties = (Map<String, Object>) beanContext.getBean(messagePropertiesBeanId); if (bProperties == null) { throw new SmooksConfigurationException("No properties map could be found under the beanId '" + messagePropertiesBeanId.getName() + "'"); } props.putAll(bProperties); } return props; } private HashMap<String, Object> evaluateStaticMessageProperties(ExecutionContext executionContext) { HashMap<String, Object> props = new HashMap<String, Object>(); for (MessageProperty messageProperty : getStaticMessageProperties(executionContext)) { props.put(messageProperty.getName(), messageProperty.getValue(executionContext)); } return props; } /** * Processes the static message properties. * Because these are static it is only done the first time. From that point on * a cached result is used. * * @param executionContext * @return */ private List<MessageProperty> getStaticMessageProperties(ExecutionContext executionContext) { if (staticMessageProperties == null) { List<MessageProperty> lMessageProperties = new ArrayList<MessageProperty>(); Parameter messagePropertiesParam = config.getParameter(PARAMETER_MESSAGE_PROPERTIES); if (messagePropertiesParam != null) { Element messagePropertiesParamElement = messagePropertiesParam.getXml(); if (messagePropertiesParamElement != null) { boolean extendedConfig = messagePropertiesParamElement.getNamespaceURI() .equals(Constants.MULE_SMOOKS_NAMESPACE); if (extendedConfig) { resolvePropertiesExtendedConfig(executionContext, lMessageProperties, messagePropertiesParamElement); } else { resolvePropertiesNormalConfig(executionContext, lMessageProperties, messagePropertiesParamElement); } } else { log.error( "Sorry, the Javabean populator bindings must be available as XML DOM. Please configure using XML."); } } staticMessageProperties = lMessageProperties; } return staticMessageProperties; } /** * @param executionContext * @param lMessageProperties * @param messagePropertiesParamElement */ private void resolvePropertiesNormalConfig(ExecutionContext executionContext, List<MessageProperty> lMessageProperties, Element messagePropertiesParamElement) { NodeList properties = messagePropertiesParamElement.getElementsByTagName(MESSAGE_PROPERTIES_NODE_NAME); for (int i = 0; properties != null && i < properties.getLength(); i++) { Element node = (Element) properties.item(i); String name = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_ATTRIBUTE_NAME); if (StringUtils.isBlank(name)) { throw new SmooksConfigurationException( "The 'name' attribute isn't a defined or empty for the message property: " + node); } name = name.trim(); MessagePropertyValue messageValue = null; String rawValue = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_PARAMETER_VALUE); if (rawValue == null) { String expression = DomUtils.getAllText(node, true); if (StringUtils.isNotBlank(expression)) { MVELExpressionEvaluator evaluator = new MVELExpressionEvaluator(); try { evaluator.setExpression(expression); } catch (RuntimeException e) { throw new RuntimeException( "Exception while setting the expression on the MVELExpressionEvaluator", e); } messageValue = new MVELEvaluatingMessagePropertyValue(evaluator); } } else { rawValue = rawValue.trim(); Object value = null; String type = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_PARAMETER_TYPE); if (type != null) { type = type.trim(); value = getDecoder(executionContext, type).decode(rawValue); } else { value = rawValue; } messageValue = new StaticMessagePropertyValue(value); } lMessageProperties.add(new MessageProperty(name, messageValue)); } } /** * @param executionContext * @param lMessageProperties * @param messagePropertiesParamElement */ private void resolvePropertiesExtendedConfig(ExecutionContext executionContext, List<MessageProperty> lMessageProperties, Element messagePropertiesParamElement) { NodeList properties = messagePropertiesParamElement.getElementsByTagNameNS(Constants.MULE_SMOOKS_NAMESPACE, MESSAGE_PROPERTIES_NODE_NAME); for (int i = 0; properties != null && i < properties.getLength(); i++) { Element node = (Element) properties.item(i); String name = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_ATTRIBUTE_NAME); if (StringUtils.isBlank(name)) { throw new SmooksConfigurationException( "The 'name' attribute isn't a defined or empty for the message property: " + node); } name = name.trim(); MessagePropertyValue messageValue = null; String rawValue = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_PARAMETER_VALUE); if (rawValue == null) { Element expressionElement = (Element) DomUtils.getElement(node, MESSAGE_EXPRESSION_NODE_NAME, 1, Constants.MULE_SMOOKS_NAMESPACE); String expression = DomUtils.getAllText(expressionElement, true); if (StringUtils.isNotBlank(expression)) { MVELExpressionEvaluator evaluator = new MVELExpressionEvaluator(); try { evaluator.setExpression(expression); } catch (RuntimeException e) { throw new RuntimeException( "Exception while setting the expression on the MVELExpressionEvaluator", e); } messageValue = new MVELEvaluatingMessagePropertyValue(evaluator); } } else { rawValue = rawValue.trim(); Object value = null; String decoder = DomUtils.getAttributeValue(node, MESSAGE_PROPERTIES_PARAMETER_DECODER); if (decoder != null) { decoder = decoder.trim(); value = getDecoder(executionContext, decoder).decode(rawValue); } else { value = rawValue; } messageValue = new StaticMessagePropertyValue(value); } lMessageProperties.add(new MessageProperty(name, messageValue)); } } /** * Retrieves the decoder of a certain type. * * @param executionContext * @param type * @return * @throws DataDecodeException */ private DataDecoder getDecoder(ExecutionContext executionContext, String type) throws DataDecodeException { @SuppressWarnings("unchecked") List<DataDecoder> decoders = executionContext.getDeliveryConfig().getObjects("decoder:" + type); DataDecoder decoder; if (decoders == null || decoders.isEmpty()) { decoder = DataDecoder.Factory.create(type); } else if (!(decoders.get(0) instanceof DataDecoder)) { throw new DataDecodeException("Configured decoder '" + type + ":" + decoders.get(0).getClass().getName() + "' is not an instance of " + DataDecoder.class.getName()); } else { decoder = decoders.get(0); } return decoder; } /* (non-Javadoc) * @see org.milyn.delivery.ordering.Consumer#consumes(java.lang.Object) */ public boolean consumes(Object object) { if (object.toString().equals(beanIdName)) { return true; } if (object.toString().equals(messagePropertiesBeanIdName)) { return true; } return false; } /* (non-Javadoc) * @see org.milyn.delivery.ordering.Producer#getProducts() */ public Set<? extends Object> getProducts() { if (resultBeanIdName == null) { return Collections.emptySet(); } return CollectionsUtil.toSet(resultBeanIdName); } }