前端传给后台JSON字符串，后台转换为List

前端：
$.ajax({
            url: "/exam/submitZB",
            type: "post",
            data: {"qssj": qssj,"ksdh": ksdh,"STlist":JSON.stringify(STlist)},        //将对象转换为JSON字符串
            dataType: "json",
            async:false,
            success:function () {
                alert("交卷成功");
                window.location.href="./hsz_preparationexam.html";

            }
        })

Controller：

    @RequestMapping("/submitZB")
    public ResultEntity submitZB(String ksdh, String qssj,HttpServletRequest request,String STlist){try{
            //提交试卷（主表信息:开始时间，考试人，结束时间，考试单号，试卷单号）
            KSXXMAIN ksxxmain = new KSXXMAIN();
            for (int i=ksdh.length();i<6;i++){
                ksdh = "0"+ ksdh;
            }
            String dh = getProcedure.getSixCode("nms_ksxx_main_dh");    //流水号
            ksxxmain.setDh(dh);
            Date begin =DateToString.stringToDateMore(qssj);
            ksxxmain.setQssj(begin);
            ksxxmain.setKsdh(ksdh);
            //设置存到数据库的考试人(获取登录用户)
            HttpSession session = request.getSession();
            Login info = (Login) session.getAttribute("info");
            ksxxmain.setKsr(info.getUsername());
            //结束时间
            ksxxmain.setJssj(new Date());
            examService.submitZB(ksxxmain);

            //提交试卷（从表信息：填写答案，试题代码，单号）
            List<SJXXNEXTGroup> list = JSON.parseObject(STlist,new TypeReference<List<SJXXNEXTGroup>>(){}); // Json 转List
            for (SJXXNEXTGroup cbMessage: list) {
                examService.submitCB(cbMessage.getTxda(),cbMessage.getStdm(), dh);
            }
            return ResultEntity.success();
        }catch (Exception e){
            e.printStackTrace();
            return ResultEntity.error();
        }

    }