使用Ajax往后台传递参数时后台无法获取参数

前台代码

            $("#cancel").click(function() {
                var lostId=$("#id").val();
                 if (confirm("确定取消申请？")) {
                 $.ajax({
                        type: "POST",
                        dataType: "json",
                        url: "${rootUrl }app/login/mobile/test",
                        data:{"lostId":lostId},
                        processData: false,
                        contentType: false,
                        success: function (response) {
                            alertMsg(response.message);
                            if(response.result == 'success'){
                                 setTimeout(function(){    
                                    window.location="${rootUrl }app/login/mobile/manage";
                                },1000); 
                            }else{
                            }
                        },
                        error : function() {
                            alertMsg("服务器繁忙, 请稍后重试!");
                            updateButton(true, "cancel", true);
                        }
                    });
                 }
            }); 
后台代码
```java
    @RequestMapping(value = "/test" ,method = RequestMethod.POST)
    public void test(HttpServletRequest request, HttpServletResponse response,Model model) throws ManagerException, IOException
    {        
            System.out.println("a");
            String id = request.getParameter("lostId");
            System.out.println(id);
            logger.info("cancel start");
            HttpMimeResponseHelper.responseJson("{\"result\":\"success\",\"message\":\"返回成功\"}", response);
            logger.info("cancel end");
    }

控制台结果如下 id无法获取为null

a
null
2021-11-15 16:27:28 [http-nio-80-exec-21]
INFO: cancel start
2021-11-15 16:27:28 [http-nio-80-exec-21]
INFO: cancel end

在js前用alert可以查出id不为空

f12抓包，看请求参数是不是空的