class GTVGFilter implements Filter {

    private ITemplateEngine templateEngine;
    private JakartaServletWebApplication application;

    
    public GTVGFilter() {
        super();
    }
    
    
    
    private static void addUserToSession(final HttpServletRequest request) {
        // Simulate a real user session by adding a user object
        request.getSession(true).setAttribute("user", new User("John", "Apricot", "Antarctica", null));
    }




    public void init(final FilterConfig filterConfig) throws ServletException {
        this.application =
                JakartaServletWebApplication.buildApplication(filterConfig.getServletContext());
        this.templateEngine = buildTemplateEngine(this.application);
    }




    public void doFilter(final ServletRequest request, final ServletResponse response,
                         final FilterChain chain) throws IOException, ServletException {
        addUserToSession((HttpServletRequest)request);
        if (!process((HttpServletRequest)request, (HttpServletResponse)response)) {
            chain.doFilter(request, response);
        }
    }




    public void destroy() {
        // nothing to do
    }

    


    private boolean process(final HttpServletRequest request, final HttpServletResponse response)
            throws ServletException {<FILL_FUNCTION_BODY>}
    

    private static ITemplateEngine buildTemplateEngine(final IWebApplication application) {

        final WebApplicationTemplateResolver templateResolver = new WebApplicationTemplateResolver(application);

        // HTML is the default mode, but we will set it anyway for better understanding of code
        templateResolver.setTemplateMode(TemplateMode.HTML);
        // This will convert "home" to "/WEB-INF/templates/home.html"
        templateResolver.setPrefix("/WEB-INF/templates/");
        templateResolver.setSuffix(".html");
        // Set template cache TTL to 1 hour. If not set, entries would live in cache until expelled by LRU
        templateResolver.setCacheTTLMs(Long.valueOf(3600000L));

        // Cache is set to true by default. Set to false if you want templates to
        // be automatically updated when modified.
        templateResolver.setCacheable(true);

        final TemplateEngine templateEngine = new TemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);

        return templateEngine;

    }
    
}

        
        try {

            final IWebExchange webExchange = this.application.buildExchange(request, response);
            final IWebRequest webRequest = webExchange.getRequest();

            // This prevents triggering engine executions for resource URLs
            if (webRequest.getPathWithinApplication().startsWith("/css") ||
                    webRequest.getPathWithinApplication().startsWith("/images") ||
                    webRequest.getPathWithinApplication().startsWith("/favicon")) {
                return false;
            }

            
            /*
             * Query controller/URL mapping and obtain the controller
             * that will process the request. If no controller is available,
             * return false and let other filters/servlets process the request.
             */
            final IGTVGController controller = ControllerMappings.resolveControllerForRequest(webRequest);
            if (controller == null) {
                return false;
            }

            /*
             * Write the response headers
             */
            response.setContentType("text/html;charset=UTF-8");
            response.setHeader("Pragma", "no-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);

            /*
             * Obtain the response writer
             */
            final Writer writer = response.getWriter();

            /*
             * Execute the controller and process view template,
             * writing the results to the response writer. 
             */
            controller.process(webExchange, this.templateEngine, writer);
            
            return true;
            
        } catch (final Exception e) {
            try {
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            } catch (final IOException ignored) {
                // Just ignore this
            }
            throw new ServletException(e);
        }
        
    
<no_super_class>