Metacat

            // Check if the servlet was configured, and if not stop the

            // initialization and skip to the configuration web form when 

            // metacat is called

            boolean configured = options.getOption("configured").equals("true");

            if (!configured) {

                logMetacat.info("Options configured: " + configured);

                return;

            }

        // Each time metacat is called, see if it has been configured,

        // and if not, then go ahead and configure it's options

        boolean configured = MetaCatUtil.getOption("configured").equals("true");

        if (!configured) {

            handleServletConfiguration(request, response);

            return;

        }

    /**

     * Handle configuration of the servlet the first time that Metacat starts

     * by collecting necessary configuration information from the administrator.

     * 

     * @param request the http request information

     * @param response the http response to be sent back to the client

     */

    private void handleServletConfiguration(HttpServletRequest request,

            HttpServletResponse response) {

        String action = request.getParameter("action");

        if (action == null || !action.equals("configure")) {

            // The servlet configuration parameters have not been set, so

            // redirect to a web form for configuring metacat

            // First add attributes to the request for all configuration options

            // TODO: MBJ should not hard code these, but get them from the config

            // Then the list of attributes can be passed to the form so that the

            // form can autogenerate the right number of fields.  Still need

            // to determine a way to get some metadata about each attribute to

            // the form jsp, such as a description and possibly a widget type

            // to use and possibly a controlled values list

            request.setAttribute( "user", MetaCatUtil.getOption("user"));

            request.setAttribute( "password", MetaCatUtil.getOption("password"));

            // Forward the request

            forwardRequest(request, response, 

                    MetaCatUtil.getOption("configurationPage"));

        } else {

            // The configuration form is being submitted and needs to be

            // processed, setting the properties in the configuration file

            // then restarting metacat

            // TODO: Should first validate that the options provided are 

            // legitimate, and possibly even test them (for example, use

            // the database connection info to connect to the database)

            // TODO: MBJ should not hard code these, but get them from the config

            checkAndSetOption(request, response, "user");

            checkAndSetOption(request, response, "password");

            // Now that the options have been set, change the 'configured'

            // option to 'true' so that normal metacat requests will go through

            MetaCatUtil.setOption("configured", "true");

            // Reload the servlet so that the database connections are loaded

            // In the absence of being able to do this programatically, then

            // redirect to a response page with instructions to restart

            forwardRequest(request, response, 

                    MetaCatUtil.getOption("configurationSuccessPage"));

        }

    }

    /**

     * Take input from the user in an HTTP request about an option to be 

     * changed and update the options property file with that new value

     * if it has changed from the value that was originally set.

     * 

     * @param request that was generated by the user

     * @param response to send output back to the user

     * @param optionName the name of the option to be checked and set

     */

    private void checkAndSetOption(HttpServletRequest request,

            HttpServletResponse response, String optionName) {

        String value = MetaCatUtil.getOption(optionName);

        String newValue = request.getParameter(optionName);

        if (!newValue.equals(value)) {

            MetaCatUtil.setOption(optionName, newValue);

        }

    }

    /**

     * Forward a request that was received by this servlet on to another 

     * JSP page or servlet to continue handling the request.  

     * 

     * @param request to be forwarded

     * @param response that can be used for writing output to the client

     * @param destination the context-relative URL to which the request is forwarded

     */

    private void forwardRequest(HttpServletRequest request,

            HttpServletResponse response, String destination) {

        try {

            getServletConfig().getServletContext().getRequestDispatcher(       

                    destination).forward(request, response);

        } catch (Exception e1) {

            try {

                PrintWriter out = response.getWriter();

                out.println("Error while forwarding to: " + destination);

                out.close();

            } catch (IOException e) {

                Logger logMetacat = Logger.getLogger(MetaCatServlet.class);

                logMetacat.debug("Unable to return error message to servlet.");

            }

        }

    }