无法将快速node.js的响应发送到我在车把模板中出现的ajax调用

Question

我正在尝试将数据从服务器端发送到我的ajax调用，但是它说net :: ERR_CONNECTION_REFUSED

我的客户端代码是

$.ajax({
                url:'http://localhost:3000/calculateCost',
                type: 'POST',
                cache: false,
                dataType: "json",
                data: {FurnitureID: fID, FurnitureQty: fQty},
                success: function(data){
                    console.log("success");
                },
                error: function(jqXHR, textStatus, err){
                    console.log("error");
                }
            })

服务器端代码

app.post('/calculateCost', urlEncodedParser, function(req, response){
    var body = req.body;
    var qstr = "SELECT Price FROM `Furniture` WHERE 1"//FurnitureID = '"+ body.FurnitureID+"'";
    con.query(qstr, function(res,err,fields){
        if(err){
            throw err;
        }
        res.send({LOLOL:"lol"});
        console.log("sent");
    });

我使用的jquery是

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>