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; import java.util.List; import java.util.concurrent.Callable; 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.Message; import org.apache.ode.bpel.iapi.MessageExchange; import org.apache.ode.bpel.iapi.PartnerRoleMessageExchange; import org.apache.ode.bpel.iapi.Scheduler; import org.apache.ode.utils.DOMUtils; import org.apache.tuscany.sca.assembly.ComponentReference; import org.apache.tuscany.sca.assembly.EndpointReference; import org.apache.tuscany.sca.interfacedef.Operation; import org.apache.tuscany.sca.interfacedef.wsdl.WSDLInterface; import org.apache.tuscany.sca.runtime.RuntimeComponent; import org.apache.tuscany.sca.runtime.RuntimeComponentReference; import org.apache.tuscany.sca.runtime.RuntimeEndpointReference; import org.w3c.dom.Document; import org.w3c.dom.Element; /** * Helper Class to handle invocation to Tuscany Component References * * @version $Rev: 881883 $ $Date: 2009-11-18 19:06:40 +0000 (Wed, 18 Nov 2009) $ */ public class ODEExternalService { protected final Log __log = LogFactory.getLog(getClass()); private EmbeddedODEServer _server; private Scheduler _sched; public ODEExternalService(EmbeddedODEServer server) { this._server = server; this._sched = _server.getScheduler(); } public void invoke(final PartnerRoleMessageExchange partnerRoleMessageExchange) { boolean isTwoWay = partnerRoleMessageExchange .getMessageExchangePattern() == org.apache.ode.bpel.iapi.MessageExchange.MessageExchangePattern.REQUEST_RESPONSE; if (isTwoWay) { // Defer the invoke until the transaction commits. _sched.registerSynchronizer(new Scheduler.Synchronizer() { public void beforeCompletion() { } public void afterCompletion(boolean success) { // If the TX is rolled back, then we don't send the request. if (!success) return; // The invocation must happen in a separate thread, holding on the afterCompletion // blocks other operations that could have been listed there as well. _server.getExecutor().submit(new Callable<Object>() { public Object call() throws Exception { try { // do execution if (!(partnerRoleMessageExchange.getChannel() instanceof TuscanyPRC)) { throw new IllegalArgumentException( "Channel should be an instance of TuscanyPRC"); } TuscanyPRC channel = (TuscanyPRC) partnerRoleMessageExchange.getChannel(); RuntimeComponent tuscanyRuntimeComponent = _server .getTuscanyRuntimeComponent(channel.getProcessName()); // Fetching the reference based on the data held in the PRC / Endpoint String refName = channel.getEndpoint().serviceName.getLocalPart(); RuntimeComponentReference runtimeComponentReference = getReferenceByName( tuscanyRuntimeComponent, refName); RuntimeEndpointReference epr = getEndpointReference(runtimeComponentReference, partnerRoleMessageExchange); // convert operations Operation operation = findOperation( partnerRoleMessageExchange.getOperation().getName(), epr); /* This is how a request looks like (payload is wrapped with extra info) <?xml version="1.0" encoding="UTF-8"?> <message> <parameters> <getGreetings xmlns="http://greetings"> <message xmlns="http://helloworld">Luciano</message> </getGreetings> </parameters> </message> */ Element msg = partnerRoleMessageExchange.getRequest().getMessage(); if (msg != null) { if (__log.isDebugEnabled()) { String xml = DOMUtils.domToString(msg); String payload = DOMUtils .domToString(getPayload(partnerRoleMessageExchange.getRequest())); __log.debug("Starting invocation of SCA Reference"); __log.debug(">>> Original message: " + xml); __log.debug(">>> Payload: " + payload); } // end if Object[] args = new Object[] { getPayload(partnerRoleMessageExchange.getRequest()) }; Object result = null; boolean success = false; try { result = epr.invoke(operation, args); success = true; } catch (Exception e) { e.printStackTrace(); partnerRoleMessageExchange.replyWithFailure( MessageExchange.FailureType.OTHER, e.getMessage(), null); } // end try if (__log.isDebugEnabled()) { __log.debug("SCA Reference invocation finished"); __log.debug(">>> Result : " + DOMUtils.domToString((Element) result)); } // end if if (!success) { return null; } // two way invocation // process results based on type of message invocation replyTwoWayInvocation(partnerRoleMessageExchange.getMessageExchangeId(), operation, (Element) result); } // end if } catch (Throwable t) { // some error String errmsg = "Error sending message (mex=" + partnerRoleMessageExchange + "): " + t.getMessage(); __log.error(errmsg, t); /*replyWithFailure(partnerRoleMessageExchange.getMessageExchangeId(), MessageExchange.FailureType.COMMUNICATION_ERROR, errmsg, null);*/ } return null; } }); } }); partnerRoleMessageExchange.replyAsync(); } else { /** one-way case * */ _server.getExecutor().submit(new Callable<Object>() { public Object call() throws Exception { // do reply // operationClient.execute(false); return null; } }); partnerRoleMessageExchange.replyOneWayOk(); } } /** * Gets a RuntimeComponentReference of a supplied RuntimeComponent by name * @param tuscanyRuntimeComponent - the runtime component * @param name - the name of the reference * @return - the RuntimeComponentReference with the supplied name - null if there is no reference with that name */ private RuntimeComponentReference getReferenceByName(RuntimeComponent tuscanyRuntimeComponent, String name) { if (name == null) return null; for (ComponentReference reference : tuscanyRuntimeComponent.getReferences()) { if (name.equals(reference.getName())) return (RuntimeComponentReference) reference; } // end for return null; } // end method getReferenceByName /** * Get the Runtime Wire for the supplied reference * @param componentReference - the reference * @return - the RuntimeWire - null if it cannot be found */ private RuntimeEndpointReference getEndpointReference(RuntimeComponentReference componentReference, PartnerRoleMessageExchange mex) { if (componentReference.isForCallback()) { // Where there is a callback, it is necessary to create a specialized wire, based on callback information // present on the forward call // Get the callbackEPR for the callback using the BPEL Process ID and the Reference name // - which is the same name as the service name for a callback Long processID = _server.getProcessIDFromMex(mex.getMessageExchangeId()); org.apache.tuscany.sca.assembly.EndpointReference callbackEPR = _server.getCallbackMetadata(processID, componentReference.getName()); RuntimeEndpointReference wire = selectCallbackWire(callbackEPR.getTargetEndpoint(), componentReference); wire = clone_bind(componentReference, callbackEPR.getCallbackEndpoint()); return wire; } else { // No callback case... //TODO - fix the x..n multiplicity case, which needs to select the correct ONE of multiple // EndpointReferences here return (RuntimeEndpointReference) componentReference.getEndpointReferences().get(0); } // end if } // end method getEndpointReference private RuntimeEndpointReference selectCallbackWire(org.apache.tuscany.sca.assembly.Endpoint endpoint, RuntimeComponentReference componentReference) { // Look for callback binding with same name as service binding if (endpoint == null) { throw new RuntimeException("Destination for forward call is not available"); } for (EndpointReference epr : componentReference.getEndpointReferences()) { if (epr.getBinding().getName().equals(endpoint.getBinding().getName())) { return (RuntimeEndpointReference) epr; } } // if no match, look for callback binding with same type as service binding for (EndpointReference epr : componentReference.getEndpointReferences()) { if (epr.getBinding().getType().equals(endpoint.getBinding().getType())) { return (RuntimeEndpointReference) epr; } } // no suitable callback wire was found return null; } // end method selectCallbackWire private RuntimeEndpointReference clone_bind(RuntimeComponentReference reference, org.apache.tuscany.sca.assembly.Endpoint callbackEndpoint) { try { // clone the callback reference ready to configure it for this callback endpoint RuntimeComponentReference ref = (RuntimeComponentReference) reference.clone(); ref.getTargets().clear(); ref.getBindings().clear(); ref.getEndpointReferences().clear(); // clone epr EndpointReference callbackEndpointReference = (EndpointReference) reference.getEndpointReferences() .get(0).clone(); callbackEndpointReference.setReference(ref); callbackEndpointReference.setTargetEndpoint(callbackEndpoint); callbackEndpointReference.setUnresolved(true); // The callback endpoint will be resolved when the wire chains are created ref.getEndpointReferences().add(callbackEndpointReference); return (RuntimeEndpointReference) ref.getEndpointReferences().get(0); } catch (CloneNotSupportedException e) { return null; } // end try clone_bind } // end method /** * Find the SCA Reference operation * * @param operationName * @param runtimeComponentReference * @return */ private Operation findOperation(String operationName, RuntimeEndpointReference epr) { Operation reseultOperation = null; for (Operation operation : epr.getComponentTypeReferenceInterfaceContract().getInterface() .getOperations()) { if (operationName.equalsIgnoreCase(operation.getName())) { reseultOperation = operation; break; } } return reseultOperation; } /** * Get payload from a given ODEMessage * @param odeMessage - the ODE message * @return the payload of the Message, as a DOM Element */ private Element getPayload(Message odeMessage) { Element payload = null; // Get the message parts - these correspond to the message parts for the invocation // as defined in the WSDL for the service operation being invoked List<String> parts = odeMessage.getParts(); if (parts.size() == 0) return null; // For the present, just deal with the ** FIRST ** part // TODO Deal with operations that have messages with multiple parts // - that will require returning an array of Elements, one for each part Element part = odeMessage.getPart(parts.get(0)); // Get the payload which is the First child if (part != null && part.hasChildNodes()) { payload = (Element) part.getFirstChild(); } return payload; } // end getPayload private void replyTwoWayInvocation(final String odeMexId, final Operation operation, final Element result) { // ODE MEX needs to be invoked in a TX. try { _server.getScheduler().execIsolatedTransaction(new Callable<Void>() { public Void call() throws Exception { PartnerRoleMessageExchange odeMex = null; try { odeMex = (PartnerRoleMessageExchange) _server.getBpelServer().getEngine() .getMessageExchange(odeMexId); if (odeMex != null) { Message response = createResponseMessage(odeMex, operation, (Element) result); odeMex.reply(response); } } catch (Exception ex) { String errmsg = "Unable to process response: " + ex.getMessage(); if (odeMex != null) { odeMex.replyWithFailure(MessageExchange.FailureType.OTHER, errmsg, null); } } return null; } }); } catch (Exception ex) { ex.printStackTrace(); } } private Message createResponseMessage(PartnerRoleMessageExchange partnerRoleMessageExchange, Operation operation, Element invocationResult) { Document dom = DOMUtils.newDocument(); String operationName = operation.getName(); Part bpelOperationOutputPart = (Part) ((WSDLInterface) operation.getInterface()).getPortType() .getOperation(operationName, null, null).getOutput().getMessage().getParts().values().iterator() .next(); Element contentMessage = dom.createElement("message"); Element contentPart = dom.createElement(bpelOperationOutputPart.getName()); contentPart.appendChild(dom.importNode(invocationResult, true)); contentMessage.appendChild(contentPart); dom.appendChild(contentMessage); if (__log.isDebugEnabled()) { __log.debug("Creating result message:"); __log.debug(">>>" + DOMUtils.domToString(dom.getDocumentElement())); } QName id = partnerRoleMessageExchange.getOperation().getOutput().getMessage().getQName(); Message response = partnerRoleMessageExchange.createMessage(id); response.setMessage(dom.getDocumentElement()); return response; } }