Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.tuscany.sca.implementation.bpel.ode.provider; import java.lang.reflect.InvocationTargetException; import java.util.concurrent.Future; import java.util.concurrent.TimeUnit; import javax.transaction.SystemException; import javax.transaction.TransactionManager; import javax.wsdl.Part; import javax.xml.namespace.QName; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.ode.bpel.iapi.MyRoleMessageExchange; import org.apache.ode.bpel.iapi.MessageExchange.Status; import org.apache.ode.utils.DOMUtils; import org.apache.ode.utils.GUID; import org.apache.tuscany.sca.assembly.Base; import org.apache.tuscany.sca.assembly.EndpointReference; import org.apache.tuscany.sca.implementation.bpel.ode.EmbeddedODEServer; import org.apache.tuscany.sca.interfacedef.Interface; import org.apache.tuscany.sca.interfacedef.Operation; import org.apache.tuscany.sca.interfacedef.wsdl.WSDLInterface; import org.apache.tuscany.sca.invocation.Invoker; import org.apache.tuscany.sca.invocation.Message; import org.apache.tuscany.sca.runtime.RuntimeComponent; import org.apache.tuscany.sca.runtime.RuntimeComponentService; import org.w3c.dom.Document; import org.w3c.dom.Element; /** * Implements a target invoker for BPEL component implementations. * * The target invoker is responsible for dispatching invocations to the particular * component implementation logic. In this example we are simply delegating the * CRUD operation invocations to the corresponding methods on our fake * resource manager. * * @version $Rev: 910275 $ $Date: 2010-02-15 17:34:56 +0000 (Mon, 15 Feb 2010) $ */ public class BPELInvoker implements Invoker { private final static long TIME_OUT = 10000L; protected final Log __log = LogFactory.getLog(getClass()); private EmbeddedODEServer odeServer; private TransactionManager txMgr; private RuntimeComponentService service; private Operation operation; private QName bpelServiceName; private String bpelOperationName; private Part bpelOperationInputPart; private Part bpelOperationOutputPart; private RuntimeComponent component; // Marks if this service has a callback interface private Boolean isCallback = false; private EndpointReference callbackEPR; public BPELInvoker(RuntimeComponent component, RuntimeComponentService service, Operation operation, EmbeddedODEServer odeServer, TransactionManager txMgr) { this.service = service; this.component = component; this.operation = operation; this.bpelOperationName = operation.getName(); this.odeServer = odeServer; this.txMgr = txMgr; this.isCallback = serviceHasCallback(service); initializeInvocation(); } // end method BPELInvoker private boolean serviceHasCallback(RuntimeComponentService service) { if (service.getInterfaceContract().getCallbackInterface() != null) return true; return false; } // end method serviceHasCallback private void initializeInvocation() { __log.debug("Initializing BPELInvoker"); Interface interfaze = operation.getInterface(); if (interfaze instanceof WSDLInterface) { WSDLInterface wsdlInterface = null; wsdlInterface = (WSDLInterface) interfaze; // Fetch the service name from the service object - including the componentURI guarantees a unique service name String componentURI = component.getURI(); bpelServiceName = new QName(Base.SCA11_TUSCANY_NS, componentURI + service.getName()); bpelOperationInputPart = (Part) wsdlInterface.getPortType().getOperation(bpelOperationName, null, null) .getInput().getMessage().getParts().values().iterator().next(); bpelOperationOutputPart = (Part) wsdlInterface.getPortType().getOperation(bpelOperationName, null, null) .getOutput().getMessage().getParts().values().iterator().next(); } } // end method initializeInvocation public Message invoke(Message msg) { try { if (isCallback) { // Extract the callback endpoint metadata callbackEPR = msg.getFrom(); } // end if Object[] args = msg.getBody(); Object resp = doTheWork(args); msg.setBody(resp); } catch (InvocationTargetException e) { msg.setFaultBody(e.getCause()); } return msg; } public Object doTheWork(Object[] args) throws InvocationTargetException { Element response = null; if (!(operation.getInterface() instanceof WSDLInterface)) { throw new InvocationTargetException(null, "Unsupported service contract"); } org.apache.ode.bpel.iapi.MyRoleMessageExchange mex = null; Future<?> onhold = null; //Process the BPEL process invocation Long processID = 0L; try { txMgr.begin(); mex = odeServer.getBpelServer().getEngine().createMessageExchange(new GUID().toString(), bpelServiceName, bpelOperationName); //TODO - this will not be true for OneWay operations - need to handle those mex.setProperty("isTwoWay", "true"); onhold = mex.invoke(createInvocationMessage(mex, args)); txMgr.commit(); // Deal with callback cases - store the callback metadata by process instance ID if (isCallback) { processID = odeServer.getProcessIDFromMex(mex.getMessageExchangeId()); // Store the callback metadata for this invocation odeServer.saveCallbackMetadata(processID, service.getName(), callbackEPR); } // end if } catch (Exception e) { try { txMgr.rollback(); } catch (SystemException se) { } throw new InvocationTargetException(e, "Error invoking BPEL process : " + e.getMessage()); } // end try // Waiting until the reply is ready in case the engine needs to continue in a different thread if (onhold != null) { try { //add timeout to avoid blocking when there is a exception/failure onhold.get(TIME_OUT, TimeUnit.MILLISECONDS); } catch (Exception e) { throw new InvocationTargetException(e, "Error invoking BPEL process : " + e.getMessage()); } // end try } // end if //Process the BPEL invocation response try { txMgr.begin(); // Reloading the mex in the current transaction, otherwise we can't // be sure we have the "freshest" one. mex = (MyRoleMessageExchange) odeServer.getBpelServer().getEngine() .getMessageExchange(mex.getMessageExchangeId()); Status status = mex.getStatus(); switch (status) { case FAULT: if (__log.isDebugEnabled()) __log.debug("Fault response message: " + mex.getFault()); throw new ODEInvocationException( "FAULT received from BPEL process : " + mex.getFault() + " " + mex.getFaultExplanation()); case ASYNC: case RESPONSE: //process the method invocation result response = processResponse(mex.getResponse().getMessage()); if (__log.isDebugEnabled()) __log.debug("Response message " + response); break; case FAILURE: if (__log.isDebugEnabled()) __log.debug("Failure response message: " + mex.getFault()); break; default: throw new ODEInvocationException( "FAILURE received from BPEL process : " + mex.getStatus() + " - " + mex.getFault()); } // end switch txMgr.commit(); // end of transaction two } catch (Exception e) { try { txMgr.rollback(); } catch (SystemException se) { } throw new InvocationTargetException(e, "Error retrieving BPEL process invocation status : " + e.getMessage()); } // end try // Cleanup the ODE MessageExchange object //mex.release(); return response; } /** * Create BPEL Invocation message * * BPEL invocation message like : * <message> * <TestPart> * <hello xmlns="http://tuscany.apache.org/implementation/bpel/example/helloworld.wsdl">Hello</hello> * </TestPart> * </message> * @param args * @return */ private org.apache.ode.bpel.iapi.Message createInvocationMessage( org.apache.ode.bpel.iapi.MyRoleMessageExchange mex, Object[] args) { Document dom = DOMUtils.newDocument(); Element contentMessage = dom.createElement("message"); Element contentPart = dom.createElement(bpelOperationInputPart.getName()); Element payload = null; // TODO handle WSDL input messages with multiple Parts... //TUSCANY-2321 - Properly handling Document or Element types if (args[0] instanceof Document) { payload = (Element) ((Document) args[0]).getFirstChild(); } else { payload = (Element) args[0]; } contentPart.appendChild(dom.importNode(payload, true)); contentMessage.appendChild(contentPart); dom.appendChild(contentMessage); if (__log.isDebugEnabled()) { __log.debug("Creating invocation message:"); __log.debug(">> args.....: " + DOMUtils.domToString(payload)); __log.debug(">> message..:" + DOMUtils.domToString(dom.getDocumentElement())); } org.apache.ode.bpel.iapi.Message request = mex.createMessage(new QName("", "")); request.setMessage(dom.getDocumentElement()); return request; } /** * Process BPEL response * * <message> * <TestPart> * <hello xmlns="http://tuscany.apache.org/implementation/bpel/example/helloworld.wsdl">World</hello> * </TestPart> * </message> * * @param response * @return */ private Element processResponse(Element response) { return (Element) DOMUtils.findChildByName(response, new QName("", bpelOperationOutputPart.getName())) .getFirstChild(); // MJE, 12/06/2009 - changed to return the message without the PART wrapper element, since this element is not // transmitted in the SOAP messages on the wire } // end method processResponse } // end class BPELInvoker