ajax jsonp 跨域请求

$.ajax({
            type: 'GET',
            async: false, // 设置为同步
            url: "http://127.0.0.1:7080/api/testJsonP.action",
            data: {
               subcompanyName: "北京",
               departmentname: "北京",
               userName: "程少话",
               requestid: "123456",
               reload: false
            },
            dataType: "jsonp",
            jsonp: "callback",
            jsonpCallback: "callbackSuccess",
            success: function (data) {
               console.log(data, " ..................... ");
            },
            error: function(){
               alert(">>>>>>>>> fail");
            }
         });

@RequestMapping(value = "api/testJsonP", method = RequestMethod.GET)
@ResponseBody
private String testAjaxJsonP(@RequestParam(value = "callback", required = true) String callback,
      ApiParam param, HttpServletRequest request, @RequestParam(value = "reload") boolean reload)
   {
      logger.info(reload + " " + param.toString());
      JSONObject jsonObj = new JSONObject();
      jsonObj.put("ip", getIpAddr(request));
      jsonObj.put("time",
            CommonUtil.DEFAULT_DATETIME_FORMAT.format(Calendar.getInstance().getTime()));
      jsonObj.put("callback", callback);

      StringBuilder json = new StringBuilder(callback);
      json.append("(").append(jsonObj.toString()).append(")");
      return json.toString();
   }