public void doGet()

in testing/h2console/ui/src/main/java/org/h2/server/web/H2WebServletForJakarta.java [121:196]
70 lines of code
17 McCabe index (conditional complexity)

    public void doGet(final HttpServletRequest req, final HttpServletResponse resp)
            throws IOException {
        req.setCharacterEncoding("utf-8");
        String file = req.getPathInfo();
        if (file == null) {
            resp.sendRedirect(req.getRequestURI() + "/");
            return;
        } else if (file.startsWith("/")) {
            file = file.substring(1);
        }
        file = getAllowedFile(req, file);

        // extract the request attributes
        Properties attributes = new Properties();
        Enumeration<?> en = req.getAttributeNames();
        while (en.hasMoreElements()) {
            String name = en.nextElement().toString();
            String value = req.getAttribute(name).toString();
            attributes.put(name, value);
        }
        en = req.getParameterNames();
        while (en.hasMoreElements()) {
            String name = en.nextElement().toString();
            String value = req.getParameter(name);
            attributes.put(name, value);
        }

        WebSession session = null;
        String sessionId = attributes.getProperty("jsessionid");
        if (sessionId != null) {
            session = server.getSession(sessionId);
        }
        WebApp app = new WebApp(server);
        app.setSession(session, attributes);
        String ifModifiedSince = req.getHeader("if-modified-since");

        String scheme = req.getScheme();
        StringBuilder builder = new StringBuilder(scheme).append("://").append(req.getServerName());
        int serverPort = req.getServerPort();
        if (!(serverPort == 80 && scheme.equals("http") || serverPort == 443 && scheme.equals("https"))) {
            builder.append(':').append(serverPort);
        }
        String path = builder.append(req.getContextPath()).toString();
        file = app.processRequest(file, new NetworkConnectionInfo(path, req.getRemoteAddr(), req.getRemotePort()));
        session = app.getSession();

        String mimeType = app.getMimeType();
        boolean cache = app.getCache();

        if (cache && server.getStartDateTime().equals(ifModifiedSince)) {
            resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
            return;
        }
        byte[] bytes = server.getFile(file);
        if (bytes == null) {
            resp.sendError(HttpServletResponse.SC_NOT_FOUND);
            bytes = ("File not found: " + file).getBytes(StandardCharsets.UTF_8);
        } else {
            if (session != null && file.endsWith(".jsp")) {
                String page = new String(bytes, StandardCharsets.UTF_8);
                page = PageParser.parse(page, session.map);
                bytes = page.getBytes(StandardCharsets.UTF_8);
            }
            resp.setContentType(mimeType);
            if (!cache) {
                resp.setHeader("Cache-Control", "no-cache");
            } else {
                resp.setHeader("Cache-Control", "max-age=10");
                resp.setHeader("Last-Modified", server.getStartDateTime());
            }
        }
        if (bytes != null) {
            ServletOutputStream out = resp.getOutputStream();
            out.write(bytes);
        }
    }