【ERROR】使用jquery的ajax出现error:readyState=4,status=500

$.ajax({
            url : "../toBeFinMisManage/showToBeFinMisNum.action?&_dc="
                    + new Date().getTime(),
            type : "get",
            cache : false,
            dataType: "json",
            data:{}, 
            success :feedBackResult,
            error: function(XMLHttpRequest, textStatus, errorThrown) {
                alert(XMLHttpRequest.readyState);
                        alert(XMLHttpRequest.status);
                        alert(textStatus);
                      }
        });