* @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 + "'");
        }