@Override
    public String execute(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ArrayList<String> alColumns = null;
        try {
            ClienteDao_Mysql oClienteDAO = new ClienteDao_Mysql(Conexion.getConection());
            alColumns = oClienteDAO.getColumnsNames();
            String data = new Gson().toJson(alColumns);
            data = "{\"data\":" + data + "}";
            return data;
        } catch (Exception e) {
            throw new ServletException("ClienteGetcolumnsJson: View Error: " + e.getMessage());
        }
    }