node.js - node express 中ajax post请求参数接收不到？

Question

app.js

// bodyParser ：ajax 请求的配置项

// parse application/x-www-form-urlencoded 
app.use(bodyParser.urlencoded({extended: false}));

// parse application/json ：接受 json 或者可以转换为json的数据格式
app.use(bodyParser.json({type: 'application/*+json'}));

// 路由
routes(app);

user.js

"use strict";
var express = require('express');
var router = express.Router();

// 该路由使用的中间件 timeLog
router.use(function timeLog(req, res, next) {
    console.log('Time: ', Date.now());
    next();
});
// 定义网站主页的路由
router.get('/', function (req, res) {
    // console.log(req);
    res.send('user home page');
});
// 定义 about 页面的路由
router.get('/about', function (req, res) {
    console.log(req.query);
    res.send('About user');
});
// 定义 login 页面的路由
router.post('/login', function (req, res) {
    console.log(req); //**拿不到对应的ajax参数**
    res.send('user login');
});

// 定义 logout 页面的路由
router.post('/logout', function (req, res) {
    res.send('user logout');
});

module.exports = router;

page.js

 $.ajax({
    url: "http://127.0.0.1:3000/user/login",
    type: "post",
    data: {
        type: "post",
        target: "login"
    },
    callback: function (data) {
        console.log(data);
    }
})

//data 信息
Object {xhr: XMLHttpRequest, errorType: "parsererror", error: SyntaxError: Unexpected token u in JSON at position 0 at Function.parse [as parseJSON] (<anonymo…}
error
:
SyntaxError: Unexpected token u in JSON at position 0 at Function.parse [as parseJSON] (<anonymous>) at XMLHttpRequest.xhr.onreadystatechange (http://127.0.0.1:3000/src/common/zepto.js:1486:103)
errorType
:
"parsererror"
xhr
:
XMLHttpRequest
__proto__
:
Object

问题：login的post请求中获取不到相应的入参。

// 定义 login 页面的路由
router.post('/login', function (req, res) {
    console.log(req); //**拿不到对应的ajax参数**
    res.send('user login');
});

备注：我先不打算做数据库那一块，先把基本的业务逻辑写一些，下周才打算连接到数据库相关的知识 。

同时我是前端开发，所以喜欢前后端分离，而不喜欢在服务端写页面模板，谢谢！

Answer 1

// Define the route of login page

router.post('/login', function (req, res) {
    console.log(req); //**拿不到对应的ajax参数**
    res.send('user login');
});

req is undefined? Or is req.body undefined?

Is app.use('/user', user); set in the app.js file?

This is what I did, please refer to it. Your problem may be caused by incorrect settings.

Front-end

$.ajax({
  type: 'POST',
  url: '/post.html',
  data,
  success: (data, status, xhr) => {
    console.log(data);
  }
});

Backend

let data = req.body;

Answer 2

router.post('/user/login', function (req, res) {
    console.log(req); //**拿不到对应的ajax参数**
    res.send('user login');
});

or

app.use('/user',require('./user'));

Answer 3

errorType: "parsererror"

What you returned is not a JSON

Answer 4

    $.ajax({
        url: "http://127.0.0.1:3000/user/login",
        type: "post",
        contentType:'application/json',
        data: JSON.stringify({
            type: "post",
            target: "login"
        }),
        success: function (data) {
            console.log(data);
        }
    }) // 如果是用jquery的话 应该这么写