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.axis2.scripting; import org.apache.axis2.AxisFault; import org.apache.axis2.context.MessageContext; import org.apache.axis2.context.ServiceContext; import org.apache.axis2.description.AxisService; import org.apache.axis2.description.Parameter; import org.apache.axis2.receivers.AbstractInOutSyncMessageReceiver; import org.apache.axis2.scripting.convertors.ConvertorFactory; import org.apache.axis2.scripting.convertors.OMElementConvertor; import org.apache.bsf.BSFEngine; import org.apache.bsf.BSFException; import org.apache.bsf.BSFManager; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.Reader; import java.net.URL; import java.util.ArrayList; /** * An Axis2 MessageReceiver for invoking script language functions. * * The scripting support uses the Apache Bean Scripting Framework (BSF) * so the script may be written in any language supported by BSF. * * There are two ways of defining the script, either in a seperate file * or embedded in-line within the services.xml file. * * This example shows a services.xml using a seperate script file: * <code> * <serviceGroup> * <service ...> * ... * <parameter name="script">scripts/myScript.js</parameter> * </service> * </serviceGroup> * </code> * * This example shows a JavaScript function embedded within a services.xml file: * <code> * <serviceGroup> * <service ...> * ... * <parameter name="script.js"><![CDATA[ * function invoke(inMC, outMC) { * ... * } * ]]></parameter> * </service> * </serviceGroup> * </code> * * The script language is determined by the file name suffix when using scripts * in seperate files or the script parameter name suffix when using inline scripts. */ public class ScriptReceiver extends AbstractInOutSyncMessageReceiver { public static final String SCRIPT_ATTR = "script"; public static final String FUNCTION_ATTR = "function"; public static final String DEFAULT_FUNCTION = "invoke"; public static final String CONVERTOR_ATTR = "convertor"; protected static final String BSFENGINE_PROP = ScriptReceiver.class.getName() + "BSFEngine"; protected static final String CONVERTOR_PROP = ScriptReceiver.class.getName() + "OMElementConvertor"; public static final String SCRIPT_SRC_PROP = ScriptReceiver.class.getName() + "ScriptSrc"; private static final Log log = LogFactory.getLog(ScriptModule.class); public ScriptReceiver() { } /** * Invokes the service by calling the script function */ public void invokeBusinessLogic(MessageContext inMC, MessageContext outMC) throws AxisFault { try { log.debug("invoking script service"); outMC.setEnvelope(getSOAPFactory(inMC).getDefaultEnvelope()); BSFEngine engine = getBSFEngine(inMC); OMElementConvertor convertor = (OMElementConvertor) inMC.getServiceContext() .getProperty(CONVERTOR_PROP); Parameter scriptFunctionParam = inMC.getAxisService().getParameter(FUNCTION_ATTR); String scriptFunction = scriptFunctionParam == null ? DEFAULT_FUNCTION : (String) scriptFunctionParam.getValue(); ScriptMessageContext inScriptMC = new ScriptMessageContext(inMC, convertor); ScriptMessageContext outScriptMC = new ScriptMessageContext(outMC, convertor); Object[] args = new Object[] { inScriptMC, outScriptMC }; engine.call(null, scriptFunction, args); } catch (BSFException e) { throw AxisFault.makeFault(e); } } /** * Gets the BSFEngine for the script service. * * The first service invocation creates the BSFEngine and caches * it in the Axis2 ServiceContext for reuse by subsequent requests. */ protected BSFEngine getBSFEngine(MessageContext mc) throws AxisFault { BSFEngine bsfEngine; ServiceContext serviceContext = mc.getServiceContext(); synchronized (serviceContext) { bsfEngine = (BSFEngine) serviceContext.getProperty(BSFENGINE_PROP); if (bsfEngine == null) { bsfEngine = initScript(mc); } } return bsfEngine; } /** * Initializes the script service by finding the script source code, * compiling it in a BSFEngine, and creating an OMElementConvertor * for the script. */ protected BSFEngine initScript(MessageContext mc) throws AxisFault { log.debug("initializing script service"); AxisService axisService = mc.getAxisService(); String scriptName = null; String scriptSrc = null; Parameter scriptFileParam = axisService.getParameter(SCRIPT_ATTR); if (scriptFileParam != null) { // the script is defined in a seperate file scriptName = ((String) scriptFileParam.getValue()).trim(); Parameter scriptSrcParam = axisService.getParameter(SCRIPT_SRC_PROP); if (scriptSrcParam != null) { scriptSrc = (String) scriptSrcParam.getValue(); } else { scriptSrc = readScript(axisService.getClassLoader(), scriptName); } } else { // the script is defined inline within the services.xml ArrayList parameters = axisService.getParameters(); for (int i = 0; scriptFileParam == null && i < parameters.size(); i++) { Parameter p = (Parameter) parameters.get(i); if (p.getName().startsWith("script.")) { scriptFileParam = p; scriptName = p.getName(); scriptSrc = (String) p.getValue(); } } } if (scriptName == null) { throw new AxisFault("Missing script parameter"); } try { String scriptLanguage = BSFManager.getLangFromFilename(scriptName); BSFManager bsfManager = new BSFManager(); bsfManager.setClassLoader(BSFManager.class.getClassLoader()); bsfManager.declareBean("_AxisService", axisService, AxisService.class); BSFEngine bsfEngine = bsfManager.loadScriptingEngine(scriptLanguage); bsfEngine.exec(scriptName, 0, 0, scriptSrc); ServiceContext serviceContext = mc.getServiceContext(); serviceContext.setProperty(BSFENGINE_PROP, bsfEngine); OMElementConvertor convertor = ConvertorFactory.createOMElementConvertor(axisService, scriptName); serviceContext.setProperty(CONVERTOR_PROP, convertor); return bsfEngine; } catch (BSFException e) { throw AxisFault.makeFault(e); } } /** * Reads the complete script source code into a String */ protected String readScript(ClassLoader cl, String scriptName) throws AxisFault { URL url = cl.getResource(scriptName); if (url == null) { throw new AxisFault("Script not found: " + scriptName); } InputStream is; try { is = url.openStream(); } catch (IOException e) { throw new AxisFault("IOException opening script: " + scriptName, e); } try { Reader reader = new InputStreamReader(is, "UTF-8"); char[] buffer = new char[1024]; StringBuffer source = new StringBuffer(); int count; while ((count = reader.read(buffer)) > 0) { source.append(buffer, 0, count); } return source.toString(); } catch (IOException e) { throw new AxisFault("IOException reading script: " + scriptName, e); } finally { try { is.close(); } catch (IOException e) { throw new AxisFault("IOException closing script: " + scriptName, e); } } } }