jquery ajax not不通过Spring Controller将数据发送回JSP

Question

我试图通过Spring MVC对Java方法进行ajax调用（返回一个String）。下面这个javascript代码成功调用Java方法并打印出我对eclipse控制台的期望。我正在尝试输出我刚才在html页面上提到的文本。我的问题是成功或错误回调函数都没有输入，所以很明显我无法获得Java方法返回的信息。

提前致谢

$("#dateButton").click(function(e){

            fromdate = $("input#fromdate").val();
            todate = $("input#todate").val();
            fromcurr = $("input#fromcurr").val();

            tocurr = $("input#tocurr").val();

            var dataString = "fromdate=" +fromdate+"&todate="+todate+"&fromcurr="+fromcurr+"&tocurr="+tocurr;
            $.ajax({
                type: "post",
                url: "getDailyRates.html",
                data: dataString,
                datatype: "text",
                async: 'false',
                success: function(data, textStatus, jqXHR){
                    alert("in success");
                    $('#display').html("");

                    $('#display').append(data);
                },
                error: function(){
                    alert("ERROR!");
                }
            });



        });

Java方法

@RequestMapping(value = "/getDailyRates.html", method = RequestMethod.POST)
    public String getDailyRates(HttpServletRequest request, HttpServletResponse response ) {

        DailyRatesQuery dailyRate= new DailyRatesQuery();
        String fromCurr= request.getParameter("fromcurr");
        String toCurr= request.getParameter("tocurr"); 
        String fromDate= request.getParameter("fromdate"); 
        String toDate=request.getParameter("todate");

        dailyRate.setFromCurr(fromCurr);
        dailyRate.setToCurr(toCurr);
        dailyRate.setFromDate(fromDate);
        dailyRate.setToDate(toDate);


        System.out.println("From Currency: "+fromCurr+" To Currency: "+toCurr+
                " fromDate: "+fromDate+" toDate: "+toDate);


        List<DailyRate> rates = jdbcRateDao.getDailyRates(dailyRate);


        System.out.println("Before return new model");
        System.out.println(rates.toString());
        return rates.get(0).toString();

    }

更新：

当我单击JavaScript函数映射到的按钮时，我发布的Java方法被成功调用并生成正确的输出。它只是没有将输出发送回我的JSP。