Giúp giải thích đoạn code có RequestMapping

[Hao_Ti_Mat_Hip (Hảo Tí)]

 @RequestMapping(value = "/noittru_xetnghiem_insert_chitiet", produces = "application/json; charset=utf-8")
    public @ResponseBody
    String noittru_xetnghiem_insert_chitiet(@RequestParam(value = "url") String url, HttpSession session) throws UnsupportedEncodingException {
        XetnghiemnoitruObj xn = new XetnghiemnoitruObj();
        url = URLDecoder.decode(url, "UTF-8");
        String[] arr = url.split("```");
        xn.sophieuxn = arr[0];
        xn.maxetnghiem = arr[1];
        xn.dvtt = arr[2];
        xn.soluong = arr[3];
        xn.dongia = arr[4];
        xn.thanhtien = arr[5];
        xn.bhytkhongchi = Boolean.parseBoolean(arr[6]);
        xn.stt_dieutri = arr[7];
        xn.stt_benhan = arr[8];
        xn.stt_dotdieutri = arr[9];
        xn.sovaovien = Integer.parseInt(arr[10]);
        xn.sovaovien_dt = Integer.parseInt(arr[11]);
        xn.mabenhnhan = arr[12];
        return CanlamsangDAO.noittru_xetnghiem_insert_chitiet(xn);
    }