无法获取 nodeJS Express 帖子以显示正文数据

Question

我觉得我已经尝试了所有方法，希望能以新的眼光来看待我的问题。正如标题所示，我正在向运行 express 的 NodeJS 服务器发送一个 http post 请求，并且 nodeJS 将 req.body 返回为未定义/空。

NodeJS 快速代码：

const express = require('express');
const path = require('path');
const app = express();
const PORT = process.env.PORT || 5000;

app.use(function(req, res, next) {
 res.header("Access-Control-Allow-Origin", "*");
 res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, 
 Content-Type, Accept");
 next();
});

app.post('/addComment', (req, res) => {
 console.log(req.body);
});

app.listen(PORT, () => console.log(`Listening on ${ PORT }`));

Javascript 浏览器代码：

let data = {name: 'aName'};

fetch('http://localhost:5000/addComment', {
 method: 'post',
 body: JSON.stringify(data)
});

Answer 1

你必须使用body-parser中间件：

const bodyParser = require('body-parser')
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json());
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, 
Content-Type, Accept");
next();
});
app.post('/addComment', (req, res) => {
console.log(req.body);
});

app.listen(PORT, () => console.log(`Listening on ${ PORT }`));

见body-parser。

Answer 2

如果你用的是最新的express，其实可以用do

    const express = require('express');
    const path = require('path');
    const app = express();
    const PORT = process.env.PORT || 5000;

    app.use(express.json()) 
    app.use (express.urlencoded({extended: false}))

    app.use(function(req, res, next) {
       res.header("Access-Control-Allow-Origin", "*");
       res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, 
       Content-Type, Accept");
       next();
   });

   app.post('/addComment', (req, res) => {
       console.log(req.body);
   });

   app.listen(PORT, () => console.log(`Listening on ${ PORT }`));

由于大众需求，Express 现在默认捆绑 body-parser。