/*
    * $Id: ActionServlet.java 483039 2006-12-06 11:34:28Z niallp $
    *
    * 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.struts.action;
  
  import org.apache.commons.beanutils.BeanUtils;
  import org.apache.commons.beanutils.ConvertUtils;
  import org.apache.commons.beanutils.PropertyUtils;
  import org.apache.commons.beanutils.converters.BigDecimalConverter;
  import org.apache.commons.beanutils.converters.BigIntegerConverter;
  import org.apache.commons.beanutils.converters.BooleanConverter;
  import org.apache.commons.beanutils.converters.ByteConverter;
  import org.apache.commons.beanutils.converters.CharacterConverter;
  import org.apache.commons.beanutils.converters.DoubleConverter;
  import org.apache.commons.beanutils.converters.FloatConverter;
  import org.apache.commons.beanutils.converters.IntegerConverter;
  import org.apache.commons.beanutils.converters.LongConverter;
  import org.apache.commons.beanutils.converters.ShortConverter;
  import org.apache.commons.chain.CatalogFactory;
  import org.apache.commons.chain.config.ConfigParser;
  import org.apache.commons.digester.Digester;
  import org.apache.commons.digester.RuleSet;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.struts.Globals;
  import org.apache.struts.config.ActionConfig;
  import org.apache.struts.config.ConfigRuleSet;
  import org.apache.struts.config.ExceptionConfig;
  import org.apache.struts.config.FormBeanConfig;
  import org.apache.struts.config.FormPropertyConfig;
  import org.apache.struts.config.ForwardConfig;
  import org.apache.struts.config.MessageResourcesConfig;
  import org.apache.struts.config.ModuleConfig;
  import org.apache.struts.config.ModuleConfigFactory;
  import org.apache.struts.config.PlugInConfig;
  import org.apache.struts.util.MessageResources;
  import org.apache.struts.util.MessageResourcesFactory;
  import org.apache.struts.util.ModuleUtils;
  import org.apache.struts.util.RequestUtils;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  
  import javax.servlet.ServletContext;
  import javax.servlet.ServletException;
  import javax.servlet.UnavailableException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.net.URLConnection;
  
  import java.util.ArrayList;
  import java.util.Enumeration;
  import java.util.Iterator;
  import java.util.List;
  import java.util.MissingResourceException;
  
  /**
   * <p><strong>ActionServlet</strong> provides the "controller" in the
   * Model-View-Controller (MVC) design pattern for web applications that is
   * commonly known as "Model 2".  This nomenclature originated with a
   * description in the JavaServerPages Specification, version 0.92, and has
   * persisted ever since (in the absence of a better name).</p>
   *
   * <p>Generally, a "Model 2" application is architected as follows:</p>
   *
   * <ul>
   *
   * <li>The user interface will generally be created with server pages, which
   * will not themselves contain any business logic. These pages represent the
   * "view" component of an MVC architecture.</li>
   *
   * <li>Forms and hyperlinks in the user interface that require business logic
   * to be executed will be submitted to a request URI that is mapped to this
  * servlet.</li>
  *
  * <li>There can be <b>one</b> instance of this servlet class, which receives
  * and processes all requests that change the state of a user's interaction
  * with the application. The servlet delegates the handling of a request to a
  * {@link RequestProcessor} object. This component represents the "controller"
  * component of an MVC architecture. </li>
  *
  * <li>The <code>RequestProcessor</code> selects and invokes an {@link Action}
  * class to perform the requested business logic, or delegates the response to
  * another resource.</li>
  *
  * <li>The <code>Action</code> classes can manipulate the state of the
  * application's interaction with the user, typically by creating or modifying
  * JavaBeans that are stored as request or session attributes (depending on
  * how long they need to be available). Such JavaBeans represent the "model"
  * component of an MVC architecture.</li>
  *
  * <li>Instead of producing the next page of the user interface directly,
  * <code>Action</code> classes generally return an {@link ActionForward} to
  * indicate which resource should handle the response. If the
  * <code>Action</code> does not return null, the <code>RequestProcessor</code>
  * forwards or redirects to the specified resource (by utilizing
  * <code>RequestDispatcher.forward</code> or <code>Response.sendRedirect</code>)
  * so as to produce the next page of the user interface.</li>
  *
  * </ul>
  *
  * <p>The standard version of <code>RequestsProcessor</code> implements the
  * following logic for each incoming HTTP request. You can override some or
  * all of this functionality by subclassing this object and implementing your
  * own version of the processing.</p>
  *
  * <ul>
  *
  * <li>Identify, from the incoming request URI, the substring that will be
  * used to select an action procedure.</li>
  *
  * <li>Use this substring to map to the Java class name of the corresponding
  * action class (an implementation of the <code>Action</code> interface).
  * </li>
  *
  * <li>If this is the first request for a particular <code>Action</code>
  * class, instantiate an instance of that class and cache it for future
  * use.</li>
  *
  * <li>Optionally populate the properties of an <code>ActionForm</code> bean
  * associated with this mapping.</li>
  *
  * <li>Call the <code>execute</code> method of this <code>Action</code> class,
  * passing on a reference to the mapping that was used, the relevant form-bean
  * (if any), and the request and the response that were passed to the
  * controller by the servlet container (thereby providing access to any
  * specialized properties of the mapping itself as well as to the
  * ServletContext). </li>
  *
  * </ul>
  *
  * <p>The standard version of <code>ActionServlet</code> is configured based
  * on the following servlet initialization parameters, which you will specify
  * in the web application deployment descriptor (<code>/WEB-INF/web.xml</code>)
  * for your application.  Subclasses that specialize this servlet are free to
  * define additional initialization parameters. </p>
  *
  * <ul>
  *
  * <li><strong>config</strong> - Comma-separated list of context-relative
  * path(s) to the XML resource(s) containing the configuration information for
  * the default module.  (Multiple files support since Struts 1.1)
  * [/WEB-INF/struts-config.xml].</li>
  *
  * <li><strong>config/${module}</strong> - Comma-separated list of
  * Context-relative path(s) to the XML resource(s) containing the
  * configuration information for the module that will use the specified prefix
  * (/${module}). This can be repeated as many times as required for multiple
  * modules. (Since Struts 1.1)</li>
  *
  * <li><strong>configFactory</strong> - The Java class name of the
  * <code>ModuleConfigFactory</code> used to create the implementation of the
  * ModuleConfig interface. </li>
  *
  * <li><strong>convertNull</strong> - Force simulation of the Struts 1.0
  * behavior when populating forms. If set to true, the numeric Java wrapper
  * class types (like <code>java.lang.Integer</code>) will default to null
  * (rather than 0). (Since Struts 1.1) [false] </li>
  *
  * <li><strong>rulesets </strong> - Comma-delimited list of fully qualified
  * classnames of additional <code>org.apache.commons.digester.RuleSet</code>
  * instances that should be added to the <code>Digester</code> that will be
  * processing <code>struts-config.xml</code> files.  By default, only the
  * <code>RuleSet</code> for the standard configuration elements is loaded.
  * (Since Struts 1.1)</li>
  *
  * <li><strong>validating</strong> - Should we use a validating XML parser to
  * process the configuration file (strongly recommended)? [true]</li>
  *
  * <li><strong>chainConfig</strong> - Comma-separated list of either
  * context-relative or classloader path(s) to load commons-chain catalog
  * definitions from.  If none specified, the default Struts catalog that is
  * provided with Struts will be used.</li>
  *
  * </ul>
  *
  * @version $Rev: 483039 $ $Date: 2005-10-14 19:54:16 -0400 (Fri, 14 Oct 2005)
  *          $
  */
 public class ActionServlet extends HttpServlet {
     /**
      * <p>Commons Logging instance.</p>
      *
      * @since Struts 1.1
      */
     protected static Log log = LogFactory.getLog(ActionServlet.class);
 
     // ----------------------------------------------------- Instance Variables
 
     /**
      * <p>Comma-separated list of context-relative path(s) to our
      * configuration resource(s) for the default module.</p>
      */
     protected String config = "/WEB-INF/struts-config.xml";
 
     /**
      * <p>Comma-separated list of context or classloader-relative path(s) that
      * contain the configuration for the default commons-chain
      * catalog(s).</p>
      */
     protected String chainConfig = "org/apache/struts/chain/chain-config.xml";
 
     /**
      * <p>The Digester used to produce ModuleConfig objects from a Struts
      * configuration file.</p>
      *
      * @since Struts 1.1
      */
     protected Digester configDigester = null;
 
     /**
      * <p>The flag to request backwards-compatible conversions for form bean
      * properties of the Java wrapper class types.</p>
      *
      * @since Struts 1.1
      */
     protected boolean convertNull = false;
 
     /**
      * <p>The resources object for our internal resources.</p>
      */
     protected MessageResources internal = null;
 
     /**
      * <p>The Java base name of our internal resources.</p>
      *
      * @since Struts 1.1
      */
     protected String internalName = "org.apache.struts.action.ActionResources";
 
     /**
      * <p>The set of public identifiers, and corresponding resource names, for
      * the versions of the configuration file DTDs that we know about.  There
      * <strong>MUST</strong> be an even number of Strings in this list!</p>
      */
     protected String[] registrations =
         {
             "-//Apache Software Foundation//DTD Struts Configuration 1.0//EN",
             "/org/apache/struts/resources/struts-config_1_0.dtd",
             "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN",
             "/org/apache/struts/resources/struts-config_1_1.dtd",
             "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN",
             "/org/apache/struts/resources/struts-config_1_2.dtd",
             "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN",
             "/org/apache/struts/resources/struts-config_1_3.dtd",
             "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN",
             "/org/apache/struts/resources/web-app_2_3.dtd"
         };
 
     /**
      * <p>The URL pattern to which we are mapped in our web application
      * deployment descriptor.</p>
      */
     protected String servletMapping = null; // :FIXME: - multiples?
 
     /**
      * <p>The servlet name under which we are registered in our web
      * application deployment descriptor.</p>
      */
     protected String servletName = null;
 
     // ---------------------------------------------------- HttpServlet Methods
 
     /**
      * <p>Gracefully shut down this controller servlet, releasing any
      * resources that were allocated at initialization.</p>
      */
     public void destroy() {
         if (log.isDebugEnabled()) {
             log.debug(internal.getMessage("finalizing"));
         }
 
         destroyModules();
         destroyInternal();
         getServletContext().removeAttribute(Globals.ACTION_SERVLET_KEY);
 
         // Release our LogFactory and Log instances (if any)
         ClassLoader classLoader =
             Thread.currentThread().getContextClassLoader();
 
         if (classLoader == null) {
             classLoader = ActionServlet.class.getClassLoader();
         }
 
         try {
             LogFactory.release(classLoader);
         } catch (Throwable t) {
             ; // Servlet container doesn't have the latest version
 
             // of commons-logging-api.jar installed
             // :FIXME: Why is this dependent on the container's version of
             // commons-logging? Shouldn't this depend on the version packaged
             // with Struts?
 
             /*
               Reason: LogFactory.release(classLoader); was added as
               an attempt to investigate the OutOfMemory error reported on
               Bugzilla #14042. It was committed for version 1.136 by craigmcc
             */
         }
 
         CatalogFactory.clear();
         PropertyUtils.clearDescriptors();
     }
 
     /**
      * <p>Initialize this servlet.  Most of the processing has been factored
      * into support methods so that you can override particular functionality
      * at a fairly granular level.</p>
      *
      * @throws ServletException if we cannot configure ourselves correctly
      */
     public void init() throws ServletException {
         final String configPrefix = "config/";
         final int configPrefixLength = configPrefix.length() - 1;
 
         // Wraps the entire initialization in a try/catch to better handle
         // unexpected exceptions and errors to provide better feedback
         // to the developer
         try {
             initInternal();
             initOther();
             initServlet();
             initChain();
 
             getServletContext().setAttribute(Globals.ACTION_SERVLET_KEY, this);
             initModuleConfigFactory();
 
             // Initialize modules as needed
             ModuleConfig moduleConfig = initModuleConfig("", config);
 
             initModuleMessageResources(moduleConfig);
             initModulePlugIns(moduleConfig);
             initModuleFormBeans(moduleConfig);
             initModuleForwards(moduleConfig);
             initModuleExceptionConfigs(moduleConfig);
             initModuleActions(moduleConfig);
             moduleConfig.freeze();
 
             Enumeration names = getServletConfig().getInitParameterNames();
 
             while (names.hasMoreElements()) {
                 String name = (String) names.nextElement();
 
                 if (!name.startsWith(configPrefix)) {
                     continue;
                 }
 
                 String prefix = name.substring(configPrefixLength);
 
                 moduleConfig =
                     initModuleConfig(prefix,
                         getServletConfig().getInitParameter(name));
                 initModuleMessageResources(moduleConfig);
                 initModulePlugIns(moduleConfig);
                 initModuleFormBeans(moduleConfig);
                 initModuleForwards(moduleConfig);
                 initModuleExceptionConfigs(moduleConfig);
                 initModuleActions(moduleConfig);
                 moduleConfig.freeze();
             }
 
             this.initModulePrefixes(this.getServletContext());
 
             this.destroyConfigDigester();
         } catch (UnavailableException ex) {
             throw ex;
         } catch (Throwable t) {
             // The follow error message is not retrieved from internal message
             // resources as they may not have been able to have been
             // initialized
             log.error("Unable to initialize Struts ActionServlet due to an "
                 + "unexpected exception or error thrown, so marking the "
                 + "servlet as unavailable.  Most likely, this is due to an "
                 + "incorrect or missing library dependency.", t);
             throw new UnavailableException(t.getMessage());
         }
     }
 
     /**
      * <p>Saves a String[] of module prefixes in the ServletContext under
      * Globals.MODULE_PREFIXES_KEY.  <strong>NOTE</strong> - the "" prefix for
      * the default module is not included in this list.</p>
      *
      * @param context The servlet context.
      * @since Struts 1.2
      */
     protected void initModulePrefixes(ServletContext context) {
         ArrayList prefixList = new ArrayList();
 
         Enumeration names = context.getAttributeNames();
 
         while (names.hasMoreElements()) {
             String name = (String) names.nextElement();
 
             if (!name.startsWith(Globals.MODULE_KEY)) {
                 continue;
             }
 
             String prefix = name.substring(Globals.MODULE_KEY.length());
 
             if (prefix.length() > 0) {
                 prefixList.add(prefix);
             }
         }
 
         String[] prefixes =
             (String[]) prefixList.toArray(new String[prefixList.size()]);
 
         context.setAttribute(Globals.MODULE_PREFIXES_KEY, prefixes);
     }
 
     /**
      * <p>Process an HTTP "GET" request.</p>
      *
      * @param request  The servlet request we are processing
      * @param response The servlet response we are creating
      * @throws IOException      if an input/output error occurs
      * @throws ServletException if a servlet exception occurs
      */
     public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws IOException, ServletException {
         process(request, response);
     }
 
     /**
      * <p>Process an HTTP "POST" request.</p>
      *
      * @param request  The servlet request we are processing
      * @param response The servlet response we are creating
      * @throws IOException      if an input/output error occurs
      * @throws ServletException if a servlet exception occurs
      */
     public void doPost(HttpServletRequest request, HttpServletResponse response)
         throws IOException, ServletException {
         process(request, response);
     }
 
     // --------------------------------------------------------- Public Methods
 
     /**
      * <p>Remember a servlet mapping from our web application deployment
      * descriptor, if it is for this servlet.</p>
      *
      * @param servletName The name of the servlet being mapped
      * @param urlPattern  The URL pattern to which this servlet is mapped
      */
     public void addServletMapping(String servletName, String urlPattern) {
         if (servletName == null) {
             return;
         }
 
         if (servletName.equals(this.servletName)) {
             if (log.isDebugEnabled()) {
                 log.debug("Process servletName=" + servletName
                     + ", urlPattern=" + urlPattern);
             }
 
             this.servletMapping = urlPattern;
         }
     }
 
     /**
      * <p>Return the <code>MessageResources</code> instance containing our
      * internal message strings.</p>
      *
      * @return the <code>MessageResources</code> instance containing our
      *         internal message strings.
      * @since Struts 1.1
      */
     public MessageResources getInternal() {
         return (this.internal);
     }
 
     // ------------------------------------------------------ Protected Methods
 
     /**
      * <p>Gracefully terminate use of any modules associated with this
      * application (if any).</p>
      *
      * @since Struts 1.1
      */
     protected void destroyModules() {
         ArrayList values = new ArrayList();
         Enumeration names = getServletContext().getAttributeNames();
 
         while (names.hasMoreElements()) {
             values.add(names.nextElement());
         }
 
         Iterator keys = values.iterator();
 
         while (keys.hasNext()) {
             String name = (String) keys.next();
             Object value = getServletContext().getAttribute(name);
 
             if (!(value instanceof ModuleConfig)) {
                 continue;
             }
 
             ModuleConfig config = (ModuleConfig) value;
 
             if (this.getProcessorForModule(config) != null) {
                 this.getProcessorForModule(config).destroy();
             }
 
             getServletContext().removeAttribute(name);
 
             PlugIn[] plugIns =
                 (PlugIn[]) getServletContext().getAttribute(Globals.PLUG_INS_KEY
                     + config.getPrefix());
 
             if (plugIns != null) {
                 for (int i = 0; i < plugIns.length; i++) {
                     int j = plugIns.length - (i + 1);
 
                     plugIns[j].destroy();
                 }
 
                 getServletContext().removeAttribute(Globals.PLUG_INS_KEY
                     + config.getPrefix());
             }
         }
     }
 
     /**
      * <p>Gracefully release any configDigester instance that we have created.
      * </p>
      *
      * @since Struts 1.1
      */
     protected void destroyConfigDigester() {
         configDigester = null;
     }
 
     /**
      * <p>Gracefully terminate use of the internal MessageResources.</p>
      */
     protected void destroyInternal() {
         internal = null;
     }
 
     /**
      * <p>Return the module configuration object for the currently selected
      * module.</p>
      *
      * @param request The servlet request we are processing
      * @return The module configuration object for the currently selected
      *         module.
      * @since Struts 1.1
      */
     protected ModuleConfig getModuleConfig(HttpServletRequest request) {
         ModuleConfig config =
             (ModuleConfig) request.getAttribute(Globals.MODULE_KEY);
 
         if (config == null) {
             config =
                 (ModuleConfig) getServletContext().getAttribute(Globals.MODULE_KEY);
         }
 
         return (config);
     }
 
     /**
      * <p>Look up and return the {@link RequestProcessor} responsible for the
      * specified module, creating a new one if necessary.</p>
      *
      * @param config The module configuration for which to acquire and return
      *               a RequestProcessor.
      * @return The {@link RequestProcessor} responsible for the specified
      *         module,
      * @throws ServletException If we cannot instantiate a RequestProcessor
      *                          instance a {@link UnavailableException} is
      *                          thrown, meaning your application is not loaded
      *                          and will not be available.
      * @since Struts 1.1
      */
     protected synchronized RequestProcessor getRequestProcessor(
         ModuleConfig config) throws ServletException {
         RequestProcessor processor = this.getProcessorForModule(config);
 
         if (processor == null) {
             try {
                 processor =
                     (RequestProcessor) RequestUtils.applicationInstance(config.getControllerConfig()
                                                                               .getProcessorClass());
             } catch (Exception e) {
                 throw new UnavailableException(
                     "Cannot initialize RequestProcessor of class "
                     + config.getControllerConfig().getProcessorClass() + ": "
                     + e);
             }
 
             processor.init(this, config);
 
             String key = Globals.REQUEST_PROCESSOR_KEY + config.getPrefix();
 
             getServletContext().setAttribute(key, processor);
         }
 
         return (processor);
     }
 
     /**
      * <p>Returns the RequestProcessor for the given module or null if one
      * does not exist.  This method will not create a RequestProcessor.</p>
      *
      * @param config The ModuleConfig.
      * @return The <code>RequestProcessor</code> for the given module, or
      *         <code>null</code> if one does not exist.
      */
     private RequestProcessor getProcessorForModule(ModuleConfig config) {
         String key = Globals.REQUEST_PROCESSOR_KEY + config.getPrefix();
 
         return (RequestProcessor) getServletContext().getAttribute(key);
     }
 
     /**
      * <p>Initialize the factory used to create the module configuration.</p>
      *
      * @since Struts 1.2
      */
     protected void initModuleConfigFactory() {
         String configFactory =
             getServletConfig().getInitParameter("configFactory");
 
         if (configFactory != null) {
             ModuleConfigFactory.setFactoryClass(configFactory);
         }
     }
 
     /**
      * <p>Initialize the module configuration information for the specified
      * module.</p>
      *
      * @param prefix Module prefix for this module
      * @param paths  Comma-separated list of context-relative resource path(s)
      *               for this modules's configuration resource(s)
      * @return The new module configuration instance.
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.1
      */
     protected ModuleConfig initModuleConfig(String prefix, String paths)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + prefix
                 + "' configuration from '" + paths + "'");
         }
 
         // Parse the configuration for this module
         ModuleConfigFactory factoryObject = ModuleConfigFactory.createFactory();
         ModuleConfig config = factoryObject.createModuleConfig(prefix);
 
         // Configure the Digester instance we will use
         Digester digester = initConfigDigester();
 
         List urls = splitAndResolvePaths(paths);
         URL url;
 
         for (Iterator i = urls.iterator(); i.hasNext();) {
             url = (URL) i.next();
             digester.push(config);
             this.parseModuleConfigFile(digester, url);
         }
 
         getServletContext().setAttribute(Globals.MODULE_KEY
             + config.getPrefix(), config);
 
         return config;
     }
 
     /**
      * <p>Parses one module config file.</p>
      *
      * @param digester Digester instance that does the parsing
      * @param path     The path to the config file to parse.
      * @throws UnavailableException if file cannot be read or parsed
      * @since Struts 1.2
      * @deprecated use parseModuleConfigFile(Digester digester, URL url)
      *             instead
      */
     protected void parseModuleConfigFile(Digester digester, String path)
         throws UnavailableException {
         try {
             List paths = splitAndResolvePaths(path);
 
             if (paths.size() > 0) {
                 // Get first path as was the old behavior
                 URL url = (URL) paths.get(0);
 
                 parseModuleConfigFile(digester, url);
             } else {
                 throw new UnavailableException("Cannot locate path " + path);
             }
         } catch (UnavailableException ex) {
             throw ex;
         } catch (ServletException ex) {
             handleConfigException(path, ex);
         }
     }
 
     /**
      * <p>Parses one module config file.</p>
      *
      * @param digester Digester instance that does the parsing
      * @param url      The url to the config file to parse.
      * @throws UnavailableException if file cannot be read or parsed
      * @since Struts 1.3
      */
     protected void parseModuleConfigFile(Digester digester, URL url)
         throws UnavailableException {
 
         try {
             digester.parse(url);
         } catch (IOException e) {
             handleConfigException(url.toString(), e);
         } catch (SAXException e) {
             handleConfigException(url.toString(), e);
         }
     }
 
     /**
      * <p>Simplifies exception handling in the parseModuleConfigFile
      * method.<p>
      *
      * @param path The path to which the exception relates.
      * @param e    The exception to be wrapped and thrown.
      * @throws UnavailableException as a wrapper around Exception
      */
     private void handleConfigException(String path, Exception e)
         throws UnavailableException {
         String msg = internal.getMessage("configParse", path);
 
         log.error(msg, e);
         throw new UnavailableException(msg);
     }
 
     /**
      * <p>Handle errors related to creating an instance of the specified
      * class.</p>
      *
      * @param className The className that could not be instantiated.
      * @param e         The exception that was caught.
      * @throws ServletException to communicate the error.
      */
     private void handleCreationException(String className, Exception e)
         throws ServletException {
         String errorMessage =
             internal.getMessage("configExtends.creation", className);
 
         log.error(errorMessage, e);
         throw new UnavailableException(errorMessage);
     }
 
     /**
      * <p>General handling for exceptions caught while inheriting config
      * information.</p>
      *
      * @param configType The type of configuration object of configName.
      * @param configName The name of the config that could not be extended.
      * @param e          The exception that was caught.
      * @throws ServletException to communicate the error.
      */
     private void handleGeneralExtensionException(String configType,
         String configName, Exception e)
         throws ServletException {
         String errorMessage =
             internal.getMessage("configExtends", configType, configName);
 
         log.error(errorMessage, e);
         throw new UnavailableException(errorMessage);
     }
 
     /**
      * <p>Handle errors caused by required fields that were not
      * specified.</p>
      *
      * @param field      The name of the required field that was not found.
      * @param configType The type of configuration object of configName.
      * @param configName The name of the config that's missing the required
      *                   value.
      * @throws ServletException to communicate the error.
      */
     private void handleValueRequiredException(String field, String configType,
         String configName) throws ServletException {
         String errorMessage =
             internal.getMessage("configFieldRequired", field, configType,
                 configName);
 
         log.error(errorMessage);
         throw new UnavailableException(errorMessage);
     }
 
     /**
      * <p>Initialize the plug ins for the specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.1
      */
     protected void initModulePlugIns(ModuleConfig config)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + config.getPrefix()
                 + "' plug ins");
         }
 
         PlugInConfig[] plugInConfigs = config.findPlugInConfigs();
         PlugIn[] plugIns = new PlugIn[plugInConfigs.length];
 
         getServletContext().setAttribute(Globals.PLUG_INS_KEY
             + config.getPrefix(), plugIns);
 
         for (int i = 0; i < plugIns.length; i++) {
             try {
                 plugIns[i] =
                     (PlugIn) RequestUtils.applicationInstance(plugInConfigs[i]
                         .getClassName());
                 BeanUtils.populate(plugIns[i], plugInConfigs[i].getProperties());
 
                 // Pass the current plugIn config object to the PlugIn.
                 // The property is set only if the plugin declares it.
                 // This plugin config object is needed by Tiles
                 try {
                     PropertyUtils.setProperty(plugIns[i],
                         "currentPlugInConfigObject", plugInConfigs[i]);
                 } catch (Exception e) {
                     ;
 
                     // FIXME Whenever we fail silently, we must document a valid
                     // reason for doing so.  Why should we fail silently if a
                     // property can't be set on the plugin?
 
                     /**
                      * Between version 1.138-1.140 cedric made these changes.
                      * The exceptions are caught to deal with containers
                      * applying strict security. This was in response to bug
                      * #15736
                      *
                      * Recommend that we make the currentPlugInConfigObject part
                      * of the PlugIn Interface if we can, Rob
                      */
                 }
 
                 plugIns[i].init(this, config);
             } catch (ServletException e) {
                 throw e;
             } catch (Exception e) {
                 String errMsg =
                     internal.getMessage("plugIn.init",
                         plugInConfigs[i].getClassName());
 
                 log(errMsg, e);
                 throw new UnavailableException(errMsg);
             }
         }
     }
 
     /**
      * <p>Initialize the form beans for the specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.3
      */
     protected void initModuleFormBeans(ModuleConfig config)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + config.getPrefix()
                 + "' form beans");
         }
 
         // Process form bean extensions.
         FormBeanConfig[] formBeans = config.findFormBeanConfigs();
 
         for (int i = 0; i < formBeans.length; i++) {
             FormBeanConfig beanConfig = formBeans[i];
 
             processFormBeanExtension(beanConfig, config);
         }
 
         for (int i = 0; i < formBeans.length; i++) {
             FormBeanConfig formBean = formBeans[i];
 
             // Verify that required fields are all present for the form config
             if (formBean.getType() == null) {
                 handleValueRequiredException("type", formBean.getName(),
                     "form bean");
             }
 
             // ... and the property configs
             FormPropertyConfig[] fpcs = formBean.findFormPropertyConfigs();
 
             for (int j = 0; j < fpcs.length; j++) {
                 FormPropertyConfig property = fpcs[j];
 
                 if (property.getType() == null) {
                     handleValueRequiredException("type", property.getName(),
                         "form property");
                 }
             }
 
             // Force creation and registration of DynaActionFormClass instances
             // for all dynamic form beans
             if (formBean.getDynamic()) {
                 formBean.getDynaActionFormClass();
             }
         }
     }
 
     /**
      * <p>Extend the form bean's configuration as necessary.</p>
      *
      * @param beanConfig   the configuration to process.
      * @param moduleConfig the module configuration for this module.
      * @throws ServletException if initialization cannot be performed.
      */
     protected void processFormBeanExtension(FormBeanConfig beanConfig,
         ModuleConfig moduleConfig)
         throws ServletException {
         try {
             if (!beanConfig.isExtensionProcessed()) {
                 if (log.isDebugEnabled()) {
                     log.debug("Processing extensions for '"
                         + beanConfig.getName() + "'");
                 }
 
                 beanConfig =
                     processFormBeanConfigClass(beanConfig, moduleConfig);
 
                 beanConfig.processExtends(moduleConfig);
             }
         } catch (ServletException e) {
             throw e;
         } catch (Exception e) {
             handleGeneralExtensionException("FormBeanConfig",
                 beanConfig.getName(), e);
         }
     }
 
     /**
      * <p>Checks if the current beanConfig is using the correct class based on
      * the class of its ancestor form bean config.</p>
      *
      * @param beanConfig   The form bean to check.
      * @param moduleConfig The config for the current module.
      * @return The form bean config using the correct class as determined by
      *         the config's ancestor and its own overridden value.
      * @throws UnavailableException if an instance of the form bean config
      *                              class cannot be created.
      * @throws ServletException     on class creation error
      */
     protected FormBeanConfig processFormBeanConfigClass(
         FormBeanConfig beanConfig, ModuleConfig moduleConfig)
         throws ServletException {
         String ancestor = beanConfig.getExtends();
 
         if (ancestor == null) {
             // Nothing to do, then
             return beanConfig;
         }
 
         // Make sure that this bean is of the right class
         FormBeanConfig baseConfig = moduleConfig.findFormBeanConfig(ancestor);
 
         if (baseConfig == null) {
             throw new UnavailableException("Unable to find " + "form bean '"
                 + ancestor + "' to extend.");
         }
 
         // Was our bean's class overridden already?
         if (beanConfig.getClass().equals(FormBeanConfig.class)) {
             // Ensure that our bean is using the correct class
             if (!baseConfig.getClass().equals(beanConfig.getClass())) {
                 // Replace the bean with an instance of the correct class
                 FormBeanConfig newBeanConfig = null;
                 String baseConfigClassName = baseConfig.getClass().getName();
 
                 try {
                     newBeanConfig =
                         (FormBeanConfig) RequestUtils.applicationInstance(baseConfigClassName);
 
                     // copy the values
                     BeanUtils.copyProperties(newBeanConfig, beanConfig);
 
                     FormPropertyConfig[] fpc =
                         beanConfig.findFormPropertyConfigs();
 
                     for (int i = 0; i < fpc.length; i++) {
                         newBeanConfig.addFormPropertyConfig(fpc[i]);
                     }
                 } catch (Exception e) {
                     handleCreationException(baseConfigClassName, e);
                 }
 
                 // replace beanConfig with newBeanConfig
                 moduleConfig.removeFormBeanConfig(beanConfig);
                 moduleConfig.addFormBeanConfig(newBeanConfig);
                 beanConfig = newBeanConfig;
             }
         }
 
         return beanConfig;
     }
 
     /**
      * <p>Initialize the forwards for the specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      */
     protected void initModuleForwards(ModuleConfig config)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + config.getPrefix()
                 + "' forwards");
         }
 
         // Process forwards extensions.
         ForwardConfig[] forwards = config.findForwardConfigs();
 
         for (int i = 0; i < forwards.length; i++) {
             ForwardConfig forward = forwards[i];
 
             processForwardExtension(forward, config, null);
         }
 
         for (int i = 0; i < forwards.length; i++) {
             ForwardConfig forward = forwards[i];
 
             // Verify that required fields are all present for the forward
             if (forward.getPath() == null) {
                 handleValueRequiredException("path", forward.getName(),
                     "global forward");
             }
         }
     }
 
     /**
      * <p>Extend the forward's configuration as necessary.  If actionConfig is
      * provided, then this method will process the forwardConfig as part
      * of that actionConfig.  If actionConfig is null, the forwardConfig
      * will be processed as a global forward.</p>
      *
      * @param forwardConfig the configuration to process.
      * @param moduleConfig  the module configuration for this module.
      * @param actionConfig  If applicable, the config for the current action.
      * @throws ServletException if initialization cannot be performed.
      */
     protected void processForwardExtension(ForwardConfig forwardConfig,
         ModuleConfig moduleConfig, ActionConfig actionConfig)
         throws ServletException {
         try {
             if (!forwardConfig.isExtensionProcessed()) {
                 if (log.isDebugEnabled()) {
                     log.debug("Processing extensions for '"
                         + forwardConfig.getName() + "'");
                 }
 
                 forwardConfig =
                     processForwardConfigClass(forwardConfig, moduleConfig,
                         actionConfig);
 
                 forwardConfig.processExtends(moduleConfig, actionConfig);
             }
         } catch (ServletException e) {
             throw e;
         } catch (Exception e) {
             handleGeneralExtensionException("Forward", forwardConfig.getName(),
                 e);
         }
     }
 
     /**
      * <p>Checks if the current forwardConfig is using the correct class based
      * on the class of its configuration ancestor.  If actionConfig is
      * provided, then this method will process the forwardConfig as part
      * of that actionConfig.  If actionConfig is null, the forwardConfig
      * will be processed as a global forward.</p>
      *
      * @param forwardConfig The forward to check.
      * @param moduleConfig  The config for the current module.
      * @param actionConfig  If applicable, the config for the current action.
      * @return The forward config using the correct class as determined by the
      *         config's ancestor and its own overridden value.
      * @throws UnavailableException if an instance of the forward config class
      *                              cannot be created.
      * @throws ServletException     on class creation error
      */
     protected ForwardConfig processForwardConfigClass(
         ForwardConfig forwardConfig, ModuleConfig moduleConfig,
         ActionConfig actionConfig)
         throws ServletException {
         String ancestor = forwardConfig.getExtends();
 
         if (ancestor == null) {
             // Nothing to do, then
             return forwardConfig;
         }
 
         // Make sure that this config is of the right class
         ForwardConfig baseConfig = null;
         if (actionConfig != null) {
             // Look for this in the actionConfig
             baseConfig = actionConfig.findForwardConfig(ancestor);
         }
 
         if (baseConfig == null) {
             // Either this is a forwardConfig that inherits a global config,
             //  or actionConfig is null
             baseConfig = moduleConfig.findForwardConfig(ancestor);
         }
 
         if (baseConfig == null) {
             throw new UnavailableException("Unable to find " + "forward '"
                 + ancestor + "' to extend.");
         }
 
         // Was our forwards's class overridden already?
         if (forwardConfig.getClass().equals(ActionForward.class)) {
             // Ensure that our forward is using the correct class
             if (!baseConfig.getClass().equals(forwardConfig.getClass())) {
                 // Replace the config with an instance of the correct class
                 ForwardConfig newForwardConfig = null;
                 String baseConfigClassName = baseConfig.getClass().getName();
 
                 try {
                     newForwardConfig =
                         (ForwardConfig) RequestUtils.applicationInstance(
                                 baseConfigClassName);
 
                     // copy the values
                     BeanUtils.copyProperties(newForwardConfig, forwardConfig);
                 } catch (Exception e) {
                     handleCreationException(baseConfigClassName, e);
                 }
 
                 // replace forwardConfig with newForwardConfig
                 if (actionConfig != null) {
                     actionConfig.removeForwardConfig(forwardConfig);
                     actionConfig.addForwardConfig(newForwardConfig);
                 } else {
                     // this is a global forward
                     moduleConfig.removeForwardConfig(forwardConfig);
                     moduleConfig.addForwardConfig(newForwardConfig);
                 }
                 forwardConfig = newForwardConfig;
             }
         }
 
         return forwardConfig;
     }
 
     /**
      * <p>Initialize the exception handlers for the specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.3
      */
     protected void initModuleExceptionConfigs(ModuleConfig config)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + config.getPrefix()
                 + "' forwards");
         }
 
         // Process exception config extensions.
         ExceptionConfig[] exceptions = config.findExceptionConfigs();
 
         for (int i = 0; i < exceptions.length; i++) {
             ExceptionConfig exception = exceptions[i];
 
             processExceptionExtension(exception, config, null);
         }
 
         for (int i = 0; i < exceptions.length; i++) {
             ExceptionConfig exception = exceptions[i];
 
             // Verify that required fields are all present for the config
             if (exception.getKey() == null) {
                 handleValueRequiredException("key", exception.getType(),
                     "global exception config");
             }
         }
     }
 
     /**
      * <p>Extend the exception's configuration as necessary. If actionConfig is
      * provided, then this method will process the exceptionConfig as part
      * of that actionConfig.  If actionConfig is null, the exceptionConfig
      * will be processed as a global forward.</p>
      *
      * @param exceptionConfig the configuration to process.
      * @param moduleConfig    the module configuration for this module.
      * @param actionConfig  If applicable, the config for the current action.
      * @throws ServletException if initialization cannot be performed.
      */
     protected void processExceptionExtension(ExceptionConfig exceptionConfig,
         ModuleConfig moduleConfig, ActionConfig actionConfig)
         throws ServletException {
         try {
             if (!exceptionConfig.isExtensionProcessed()) {
                 if (log.isDebugEnabled()) {
                     log.debug("Processing extensions for '"
                         + exceptionConfig.getType() + "'");
                 }
 
                 exceptionConfig =
                     processExceptionConfigClass(exceptionConfig, moduleConfig,
                         actionConfig);
 
                 exceptionConfig.processExtends(moduleConfig, actionConfig);
             }
         } catch (ServletException e) {
             throw e;
         } catch (Exception e) {
             handleGeneralExtensionException("Exception",
                 exceptionConfig.getType(), e);
         }
     }
 
     /**
      * <p>Checks if the current exceptionConfig is using the correct class
      * based on the class of its configuration ancestor. If actionConfig is
      * provided, then this method will process the exceptionConfig as part
      * of that actionConfig.  If actionConfig is null, the exceptionConfig
      * will be processed as a global forward.</p>
      *
      * @param exceptionConfig The config to check.
      * @param moduleConfig    The config for the current module.
      * @param actionConfig  If applicable, the config for the current action.
      * @return The exception config using the correct class as determined by
      *         the config's ancestor and its own overridden value.
      * @throws ServletException if an instance of the exception config class
      *                          cannot be created.
      */
     protected ExceptionConfig processExceptionConfigClass(
         ExceptionConfig exceptionConfig, ModuleConfig moduleConfig,
         ActionConfig actionConfig)
         throws ServletException {
         String ancestor = exceptionConfig.getExtends();
 
         if (ancestor == null) {
             // Nothing to do, then
             return exceptionConfig;
         }
 
         // Make sure that this config is of the right class
         ExceptionConfig baseConfig = null;
         if (actionConfig != null) {
             baseConfig = actionConfig.findExceptionConfig(ancestor);
         }
 
         if (baseConfig == null) {
             // This means either there's no actionConfig anyway, or the
             // ancestor is not defined within the action.
             baseConfig = moduleConfig.findExceptionConfig(ancestor);
         }
 
         if (baseConfig == null) {
             throw new UnavailableException("Unable to find "
                 + "exception config '" + ancestor + "' to extend.");
         }
 
         // Was our config's class overridden already?
         if (exceptionConfig.getClass().equals(ExceptionConfig.class)) {
             // Ensure that our config is using the correct class
             if (!baseConfig.getClass().equals(exceptionConfig.getClass())) {
                 // Replace the config with an instance of the correct class
                 ExceptionConfig newExceptionConfig = null;
                 String baseConfigClassName = baseConfig.getClass().getName();
 
                 try {
                     newExceptionConfig =
                         (ExceptionConfig) RequestUtils.applicationInstance(
                             baseConfigClassName);
 
                     // copy the values
                     BeanUtils.copyProperties(newExceptionConfig,
                         exceptionConfig);
                 } catch (Exception e) {
                     handleCreationException(baseConfigClassName, e);
                 }
 
                 // replace exceptionConfig with newExceptionConfig
                 if (actionConfig != null) {
                     actionConfig.removeExceptionConfig(exceptionConfig);
                     actionConfig.addExceptionConfig(newExceptionConfig);
                 } else {
                     moduleConfig.removeExceptionConfig(exceptionConfig);
                     moduleConfig.addExceptionConfig(newExceptionConfig);
                 }
                 exceptionConfig = newExceptionConfig;
             }
         }
 
         return exceptionConfig;
     }
 
     /**
      * <p>Initialize the action configs for the specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.3
      */
     protected void initModuleActions(ModuleConfig config)
         throws ServletException {
         if (log.isDebugEnabled()) {
             log.debug("Initializing module path '" + config.getPrefix()
                 + "' action configs");
         }
 
         // Process ActionConfig extensions.
         ActionConfig[] actionConfigs = config.findActionConfigs();
 
         for (int i = 0; i < actionConfigs.length; i++) {
             ActionConfig actionConfig = actionConfigs[i];
 
             processActionConfigExtension(actionConfig, config);
         }
 
         for (int i = 0; i < actionConfigs.length; i++) {
             ActionConfig actionConfig = actionConfigs[i];
 
             // Verify that required fields are all present for the forward
             // configs
             ForwardConfig[] forwards = actionConfig.findForwardConfigs();
 
             for (int j = 0; j < forwards.length; j++) {
                 ForwardConfig forward = forwards[j];
 
                 if (forward.getPath() == null) {
                     handleValueRequiredException("path", forward.getName(),
                         "action forward");
                 }
             }
 
             // ... and the exception configs
             ExceptionConfig[] exceptions = actionConfig.findExceptionConfigs();
 
             for (int j = 0; j < exceptions.length; j++) {
                 ExceptionConfig exception = exceptions[j];
 
                 if (exception.getKey() == null) {
                     handleValueRequiredException("key", exception.getType(),
                         "action exception config");
                 }
             }
         }
     }
 
     /**
      * <p>Extend the action's configuration as necessary.</p>
      *
      * @param actionConfig the configuration to process.
      * @param moduleConfig the module configuration for this module.
      * @throws ServletException if initialization cannot be performed.
      */
     protected void processActionConfigExtension(ActionConfig actionConfig,
         ModuleConfig moduleConfig)
         throws ServletException {
         try {
             if (!actionConfig.isExtensionProcessed()) {
                 if (log.isDebugEnabled()) {
                     log.debug("Processing extensions for '"
                         + actionConfig.getPath() + "'");
                 }
 
                 actionConfig =
                     processActionConfigClass(actionConfig, moduleConfig);
 
                 actionConfig.processExtends(moduleConfig);
             }
 
             // Process forwards extensions.
             ForwardConfig[] forwards = actionConfig.findForwardConfigs();
             for (int i = 0; i < forwards.length; i++) {
                 ForwardConfig forward = forwards[i];
                 processForwardExtension(forward, moduleConfig, actionConfig);
             }
 
             // Process exception extensions.
             ExceptionConfig[] exceptions = actionConfig.findExceptionConfigs();
             for (int i = 0; i < exceptions.length; i++) {
                 ExceptionConfig exception = exceptions[i];
                 processExceptionExtension(exception, moduleConfig,
                     actionConfig);
             }
         } catch (ServletException e) {
             throw e;
         } catch (Exception e) {
             handleGeneralExtensionException("Action", actionConfig.getPath(), e);
         }
     }
 
     /**
      * <p>Checks if the current actionConfig is using the correct class based
      * on the class of its ancestor ActionConfig.</p>
      *
      * @param actionConfig The action config to check.
      * @param moduleConfig The config for the current module.
      * @return The config object using the correct class as determined by the
      *         config's ancestor and its own overridden value.
      * @throws ServletException if an instance of the action config class
      *                          cannot be created.
      */
     protected ActionConfig processActionConfigClass(ActionConfig actionConfig,
         ModuleConfig moduleConfig)
         throws ServletException {
         String ancestor = actionConfig.getExtends();
 
         if (ancestor == null) {
             // Nothing to do, then
             return actionConfig;
         }
 
         // Make sure that this config is of the right class
         ActionConfig baseConfig = moduleConfig.findActionConfig(ancestor);
 
         if (baseConfig == null) {
             throw new UnavailableException("Unable to find "
                 + "action config for '" + ancestor + "' to extend.");
         }
 
         // Was our actionConfig's class overridden already?
         if (actionConfig.getClass().equals(ActionMapping.class)) {
             // Ensure that our config is using the correct class
             if (!baseConfig.getClass().equals(actionConfig.getClass())) {
                 // Replace the config with an instance of the correct class
                 ActionConfig newActionConfig = null;
                 String baseConfigClassName = baseConfig.getClass().getName();
 
                 try {
                     newActionConfig =
                         (ActionConfig) RequestUtils.applicationInstance(baseConfigClassName);
 
                     // copy the values
                     BeanUtils.copyProperties(newActionConfig, actionConfig);
 
                     // copy the forward and exception configs, too
                     ForwardConfig[] forwards =
                         actionConfig.findForwardConfigs();
 
                     for (int i = 0; i < forwards.length; i++) {
                         newActionConfig.addForwardConfig(forwards[i]);
                     }
 
                     ExceptionConfig[] exceptions =
                         actionConfig.findExceptionConfigs();
 
                     for (int i = 0; i < exceptions.length; i++) {
                         newActionConfig.addExceptionConfig(exceptions[i]);
                     }
                 } catch (Exception e) {
                     handleCreationException(baseConfigClassName, e);
                 }
 
                 // replace actionConfig with newActionConfig
                 moduleConfig.removeActionConfig(actionConfig);
                 moduleConfig.addActionConfig(newActionConfig);
                 actionConfig = newActionConfig;
             }
         }
 
         return actionConfig;
     }
 
     /**
      * <p>Initialize the application <code>MessageResources</code> for the
      * specified module.</p>
      *
      * @param config ModuleConfig information for this module
      * @throws ServletException if initialization cannot be performed
      * @since Struts 1.1
      */
     protected void initModuleMessageResources(ModuleConfig config)
         throws ServletException {
         MessageResourcesConfig[] mrcs = config.findMessageResourcesConfigs();
 
         for (int i = 0; i < mrcs.length; i++) {
             if ((mrcs[i].getFactory() == null)
                 || (mrcs[i].getParameter() == null)) {
                 continue;
             }
 
             if (log.isDebugEnabled()) {
                 log.debug("Initializing module path '" + config.getPrefix()
                     + "' message resources from '" + mrcs[i].getParameter()
                     + "'");
             }
 
             String factory = mrcs[i].getFactory();
 
             MessageResourcesFactory.setFactoryClass(factory);
 
             MessageResourcesFactory factoryObject =
                 MessageResourcesFactory.createFactory();
 
             factoryObject.setConfig(mrcs[i]);
 
             MessageResources resources =
                 factoryObject.createResources(mrcs[i].getParameter());
 
             resources.setReturnNull(mrcs[i].getNull());
             resources.setEscape(mrcs[i].isEscape());
             getServletContext().setAttribute(mrcs[i].getKey()
                 + config.getPrefix(), resources);
         }
     }
 
     /**
      * <p>Create (if needed) and return a new <code>Digester</code> instance
      * that has been initialized to process Struts module configuration files
      * and configure a corresponding <code>ModuleConfig</code> object (which
      * must be pushed on to the evaluation stack before parsing begins).</p>
      *
      * @return A new configured <code>Digester</code> instance.
      * @throws ServletException if a Digester cannot be configured
      * @since Struts 1.1
      */
     protected Digester initConfigDigester()
         throws ServletException {
         // :FIXME: Where can ServletException be thrown?
         // Do we have an existing instance?
         if (configDigester != null) {
             return (configDigester);
         }
 
         // Create a new Digester instance with standard capabilities
         configDigester = new Digester();
         configDigester.setNamespaceAware(true);
         configDigester.setValidating(this.isValidating());
         configDigester.setUseContextClassLoader(true);
         configDigester.addRuleSet(new ConfigRuleSet());
 
         for (int i = 0; i < registrations.length; i += 2) {
             URL url = this.getClass().getResource(registrations[i + 1]);
 
             if (url != null) {
                 configDigester.register(registrations[i], url.toString());
             }
         }
 
         this.addRuleSets();
 
         // Return the completely configured Digester instance
         return (configDigester);
     }
 
     /**
      * <p>Add any custom RuleSet instances to configDigester that have been
      * specified in the <code>rulesets</code> init parameter.</p>
      *
      * @throws ServletException if an error occurs
      */
     private void addRuleSets()
         throws ServletException {
         String rulesets = getServletConfig().getInitParameter("rulesets");
 
         if (rulesets == null) {
             rulesets = "";
         }
 
         rulesets = rulesets.trim();
 
         String ruleset;
 
         while (rulesets.length() > 0) {
             int comma = rulesets.indexOf(",");
 
             if (comma < 0) {
                 ruleset = rulesets.trim();
                 rulesets = "";
             } else {
                 ruleset = rulesets.substring(0, comma).trim();
                 rulesets = rulesets.substring(comma + 1).trim();
             }
 
             if (log.isDebugEnabled()) {
                 log.debug("Configuring custom Digester Ruleset of type "
                     + ruleset);
             }
 
             try {
                 RuleSet instance =
                     (RuleSet) RequestUtils.applicationInstance(ruleset);
 
                 this.configDigester.addRuleSet(instance);
             } catch (Exception e) {
                 log.error("Exception configuring custom Digester RuleSet", e);
                 throw new ServletException(e);
             }
         }
     }
 
     /**
      * <p>Check the status of the <code>validating</code> initialization
      * parameter.</p>
      *
      * @return true if the module Digester should validate.
      */
     private boolean isValidating() {
         boolean validating = true;
         String value = getServletConfig().getInitParameter("validating");
 
         if ("false".equalsIgnoreCase(value) || "no".equalsIgnoreCase(value)
             || "n".equalsIgnoreCase(value) || "0".equalsIgnoreCase(value)) {
             validating = false;
         }
 
         return validating;
     }
 
     /**
      * <p>Initialize our internal MessageResources bundle.</p>
      *
      * @throws ServletException     if we cannot initialize these resources
      * @throws UnavailableException if we cannot load  resources
      */
     protected void initInternal()
         throws ServletException {
         try {
             internal = MessageResources.getMessageResources(internalName);
         } catch (MissingResourceException e) {
             log.error("Cannot load internal resources from '" + internalName
                 + "'", e);
             throw new UnavailableException(
                 "Cannot load internal resources from '" + internalName + "'");
         }
     }
 
     /**
      * <p>Parse the configuration documents specified by the
      * <code>chainConfig</code> init-param to configure the default {@link
      * org.apache.commons.chain.Catalog} that is registered in the {@link
      * CatalogFactory} instance for this application.</p>
      *
      * @throws ServletException if an error occurs.
      */
     protected void initChain()
         throws ServletException {
         // Parse the configuration file specified by path or resource
         try {
             String value;
 
             value = getServletConfig().getInitParameter("chainConfig");
 
             if (value != null) {
                 chainConfig = value;
             }
 
             ConfigParser parser = new ConfigParser();
             List urls = splitAndResolvePaths(chainConfig);
             URL resource;
 
             for (Iterator i = urls.iterator(); i.hasNext();) {
                 resource = (URL) i.next();
                 log.info("Loading chain catalog from " + resource);
                 parser.parse(resource);
             }
         } catch (Exception e) {
             log.error("Exception loading resources", e);
             throw new ServletException(e);
         }
     }
 
     /**
      * <p>Initialize other global characteristics of the controller
      * servlet.</p>
      *
      * @throws ServletException if we cannot initialize these resources
      */
     protected void initOther()
         throws ServletException {
         String value;
 
         value = getServletConfig().getInitParameter("config");
 
         if (value != null) {
             config = value;
         }
 
         // Backwards compatibility for form beans of Java wrapper classes
         // Set to true for strict Struts 1.0 compatibility
         value = getServletConfig().getInitParameter("convertNull");
 
         if ("true".equalsIgnoreCase(value) || "yes".equalsIgnoreCase(value)
             || "on".equalsIgnoreCase(value) || "y".equalsIgnoreCase(value)
             || "1".equalsIgnoreCase(value)) {
             convertNull = true;
         }
 
         if (convertNull) {
             ConvertUtils.deregister();
             ConvertUtils.register(new BigDecimalConverter(null),
                 BigDecimal.class);
             ConvertUtils.register(new BigIntegerConverter(null),
                 BigInteger.class);
             ConvertUtils.register(new BooleanConverter(null), Boolean.class);
             ConvertUtils.register(new ByteConverter(null), Byte.class);
             ConvertUtils.register(new CharacterConverter(null), Character.class);
             ConvertUtils.register(new DoubleConverter(null), Double.class);
             ConvertUtils.register(new FloatConverter(null), Float.class);
             ConvertUtils.register(new IntegerConverter(null), Integer.class);
             ConvertUtils.register(new LongConverter(null), Long.class);
             ConvertUtils.register(new ShortConverter(null), Short.class);
         }
     }
 
     /**
      * <p>Initialize the servlet mapping under which our controller servlet is
      * being accessed.  This will be used in the <code>&html:form&gt;</code>
      * tag to generate correct destination URLs for form submissions.</p>
      *
      * @throws ServletException if error happens while scanning web.xml
      */
     protected void initServlet()
         throws ServletException {
         // Remember our servlet name
         this.servletName = getServletConfig().getServletName();
 
         // Prepare a Digester to scan the web application deployment descriptor
         Digester digester = new Digester();
 
         digester.push(this);
         digester.setNamespaceAware(true);
         digester.setValidating(false);
 
         // Register our local copy of the DTDs that we can find
         for (int i = 0; i < registrations.length; i += 2) {
             URL url = this.getClass().getResource(registrations[i + 1]);
 
             if (url != null) {
                 digester.register(registrations[i], url.toString());
             }
         }
 
         // Configure the processing rules that we need
         digester.addCallMethod("web-app/servlet-mapping", "addServletMapping", 2);
         digester.addCallParam("web-app/servlet-mapping/servlet-name", 0);
         digester.addCallParam("web-app/servlet-mapping/url-pattern", 1);
 
         // Process the web application deployment descriptor
         if (log.isDebugEnabled()) {
             log.debug("Scanning web.xml for controller servlet mapping");
         }
 
         InputStream input =
             getServletContext().getResourceAsStream("/WEB-INF/web.xml");
 
         if (input == null) {
             log.error(internal.getMessage("configWebXml"));
             throw new ServletException(internal.getMessage("configWebXml"));
         }
 
         try {
             digester.parse(input);
         } catch (IOException e) {
             log.error(internal.getMessage("configWebXml"), e);
             throw new ServletException(e);
         } catch (SAXException e) {
             log.error(internal.getMessage("configWebXml"), e);
             throw new ServletException(e);
         } finally {
             try {
                 input.close();
             } catch (IOException e) {
                 log.error(internal.getMessage("configWebXml"), e);
                 throw new ServletException(e);
             }
         }
 
         // Record a servlet context attribute (if appropriate)
         if (log.isDebugEnabled()) {
             log.debug("Mapping for servlet '" + servletName + "' = '"
                 + servletMapping + "'");
         }
 
         if (servletMapping != null) {
             getServletContext().setAttribute(Globals.SERVLET_KEY, servletMapping);
         }
     }
 
     /**
      * <p>Takes a comma-delimited string and splits it into paths, then
      * resolves those paths using the ServletContext and appropriate
      * ClassLoader.  When loading from the classloader, multiple resources per
      * path are supported to support, for example, multiple jars containing
      * the same named config file.</p>
      *
      * @param paths A comma-delimited string of paths
      * @return A list of resolved URL's for all found resources
      * @throws ServletException if a servlet exception is thrown
      */
     protected List splitAndResolvePaths(String paths)
         throws ServletException {
         ClassLoader loader = Thread.currentThread().getContextClassLoader();
 
         if (loader == null) {
             loader = this.getClass().getClassLoader();
         }
 
         ArrayList resolvedUrls = new ArrayList();
 
         URL resource;
         String path = null;
 
         try {
             // Process each specified resource path
             while (paths.length() > 0) {
                 resource = null;
 
                 int comma = paths.indexOf(',');
 
                 if (comma >= 0) {
                     path = paths.substring(0, comma).trim();
                     paths = paths.substring(comma + 1);
                 } else {
                     path = paths.trim();
                     paths = "";
                 }
 
                 if (path.length() < 1) {
                     break;
                 }
 
                 if (path.charAt(0) == '/') {
                     resource = getServletContext().getResource(path);
                 }
 
                 if (resource == null) {
                     if (log.isDebugEnabled()) {
                         log.debug("Unable to locate " + path
                             + " in the servlet context, "
                             + "trying classloader.");
                     }
 
                     Enumeration e = loader.getResources(path);
 
                     if (!e.hasMoreElements()) {
                         String msg = internal.getMessage("configMissing", path);
 
                         log.error(msg);
                         throw new UnavailableException(msg);
                     } else {
                         while (e.hasMoreElements()) {
                             resolvedUrls.add(e.nextElement());
                         }
                     }
                 } else {
                     resolvedUrls.add(resource);
                 }
             }
         } catch (MalformedURLException e) {
             handleConfigException(path, e);
         } catch (IOException e) {
             handleConfigException(path, e);
         }
 
         return resolvedUrls;
     }
 
     /**
      * <p>Perform the standard request processing for this request, and create
      * the corresponding response.</p>
      *
      * @param request  The servlet request we are processing
      * @param response The servlet response we are creating
      * @throws IOException      if an input/output error occurs
      * @throws ServletException if a servlet exception is thrown
      */
     protected void process(HttpServletRequest request,
         HttpServletResponse response)
         throws IOException, ServletException {
         ModuleUtils.getInstance().selectModule(request, getServletContext());
 
         ModuleConfig config = getModuleConfig(request);
 
         RequestProcessor processor = getProcessorForModule(config);
 
         if (processor == null) {
             processor = getRequestProcessor(config);
         }
 
         processor.process(request, response);
     }
 }