/** @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

    String action = request.getParameter("action");
    JSONArray result = new JSONArray();

    switch (action) {
      case "getComments":
        result = getComments(request.getParameter("itemNumber"));
        break;
      case "addComment":
        addComment(request.getParameter("itemNumber"), request.getParameter("comment"));
        break;
    }
    response.setContentType("text/html; charset=UTF-8");
    response.setCharacterEncoding("UTF-8");
    response.getOutputStream().print(result.serialize());
    return;
  }