2009/05/20 - Apache Shale has been retired.

 /*

  * 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.shale.dialog.scxml;

 import java.net.URL;

 import java.util.Enumeration;

 import java.util.HashMap;

 import java.util.Map;

 import javax.faces.FacesException;

 import javax.servlet.ServletContextEvent;

 import javax.servlet.ServletContextListener;

 import org.apache.commons.beanutils.PropertyUtils;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.shale.dialog.scxml.config.ConfigurationParser;

 /**

  * <p>ServletContextListener that loads dialog configuration resources

  * at application startup, and cleans up the libraries we depend on at

  * application shutdown.</p>

  *

  * $Id: SCXMLLifecycleListener.java 476713 2006-11-19 05:10:57Z rahul $

  *

  * @since 1.0.4

  */

 public class SCXMLLifecycleListener implements ServletContextListener {

     // -------------------------------------------------------- Static Variables

     /**

      * <p>The default configuration resource we will process (if present),

      * even if it is not explicitly configured.</p>

      */

     private static final String DEFAULT_CONFIGURATION_RESOURCE =

             "/WEB-INF/dialog-config.xml";

     /**

      * <p>Resource name for dialog configuration resource(s) embedded in

      * JAR files inside the application.</p>

      */

     private static final String EMBEDDED_CONFIGURATION_RESOURCE =

             "META-INF/dialog-config.xml";

     // ------------------------------------------------------ Instance Variables

     /**

      * <p>The <code>Log</code> instance we will use for this listener.</p>

      */

     private Log log = LogFactory.getLog(SCXMLLifecycleListener.class);

     // ------------------------------------------ ServletContextListener Methods

     /**

      * <p>Process the application shutdown event, cleanup resources.</p>

      *

      * @param event Shutdown event to be processed

      */

     public void contextDestroyed(ServletContextEvent event) {

         if (log.isInfoEnabled()) {

             log.info("Finalizing Dialog SCXML Implementation");

         }

         // Clean up our cache of dialog configuration information

         event.getServletContext().removeAttribute(Globals.DIALOGS);

         // Clean up dependency libraries we have used

         PropertyUtils.clearDescriptors();

         LogFactory.release(Thread.currentThread().getContextClassLoader());

         log = null;

     }

     /**

      * <p>Process the application startup event, parse dialog

      * configurations.</p>

      *

      * @param event Startup event to be processed

      */

     public void contextInitialized(ServletContextEvent event) {

         if (log.isInfoEnabled()) {

             log.info("Initializing Dialog SCXML Implementation");

         }

         // Set up to parse our specified configuration resources and cache the results

         boolean didDefault = false;

         ConfigurationParser parser = new ConfigurationParser();

         parser.setDialogs(new HashMap());

         // Parse implicitly specified resources embedded in JAR files

         ClassLoader loader = Thread.currentThread().getContextClassLoader();

         if (loader == null) {

             loader = this.getClass().getClassLoader();

         }

         try {

             Enumeration resources = loader.getResources(EMBEDDED_CONFIGURATION_RESOURCE);

             while (resources.hasMoreElements()) {

                 URL resource = (URL) resources.nextElement();

                 if (log.isDebugEnabled()) {

                     log.debug("Parsing configuration resource '"

                             + resource + "'");

                 }

                 parser.setResource(resource);

                 parser.parse();

             }

         } catch (RuntimeException e) {

             throw e;

         } catch (Exception e) {

             throw new FacesException(e);

         }

         // Parse explicitly specified resources

         String resources =

           event.getServletContext().getInitParameter(Globals.CONFIGURATION);

         if (resources == null) {

             resources = "";

         }

         int comma = 0;

         String path = null;

         try {

             while (true) {

                 comma = resources.indexOf(",");

                 if (comma < 0) {

                     path = resources.trim();

                     resources = "";

                 } else {

                     path = resources.substring(0, comma).trim();

                     resources = resources.substring(comma + 1);

                 }

                 if (path.length() < 1) {

                     break;

                 }

                 URL resource = event.getServletContext().getResource(path);

                 if (log.isDebugEnabled()) {

                     log.debug("Parsing configuration resource '"

                             + resource + "'");

                 }

                 parser.setResource(resource);

                 parser.parse();

                 if (DEFAULT_CONFIGURATION_RESOURCE.equals(path)) {

                     didDefault = true;

                 }

             }

         } catch (RuntimeException e) {

             throw e;

         } catch (Exception e) {

             throw new FacesException(e);

         }

         // Parse the default configuration resource if it exists and has not

         // already been parsed

         if (!didDefault) {

             try {

                 URL resource =

                   event.getServletContext().getResource(DEFAULT_CONFIGURATION_RESOURCE);

                 if (resource != null) {

                     if (log.isDebugEnabled()) {

                         log.debug("Parsing configuration resource '"

                                 + resource + "'");

                     }

                     parser.setResource(resource);

                     parser.parse();

                 }

             } catch (RuntimeException e) {

                 throw e;

             } catch (Exception e) {

                 throw new FacesException(e);

             }

         }

         // Cache the results in application scope

         Map dialogs = parser.getDialogs();

         if (dialogs.size() == 0) {

             if (log.isWarnEnabled()) {

                 log.warn("No dialog configuration information present.  No default configuration found at: "

                     + DEFAULT_CONFIGURATION_RESOURCE + ".  No embedded configuration found at: "

                     + EMBEDDED_CONFIGURATION_RESOURCE);

             }

         }

         event.getServletContext().setAttribute(Globals.DIALOGS, dialogs);

     }

 }