Express 4.17 req body 为空

Question

req.body总是空的。

index.js:

const express = require('express');
const app = express();
const port = 8080;

app.use(express.static('public'))
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

const userRoutes = require('./routes/user.routes');
app.use("/user", userRoutes);

app.listen(port, () => console.log("app listening."));

routes/user.路线：

const express = require('express');
const router = express.Router();

router.post('/', (req, res) => {
    res.json({ requestBody: req.body });
});

module.exports = router;

客户端脚本：

fetch('/user', {
        method: 'POST',
        body: JSON.stringify({ testData: "testData" }),
        headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json'
        },
    })
    .then(function(response) {
        return response.json();
    })
    .then(function(responseData) {
        console.log(responseData);
    })
    .then(function(result) {
        if (result.error) {
            alert(result.error.message);
        }
    });

在控制台中获取的结果：

{requestBody: {}}

Answer 1

来自 docs for req.body

By default, it is undefined, and is populated when you use body-parsing middleware such as body-parser and multer.

所以你需要使用一个中间件来填充 req.body

const bodyParser = require('body-parser')

router.use(bodyParser.json())

router.post('/', (req, res) => {
    res.json({ requestBody: req.body });
});

Answer 2

确保使用此命令在本地安装最新的 Express 版本：

npm i -S express

如果问题仍然存在，请尝试使用其他浏览器

Express 4.17 req body 为空

Express 4.17 req body is empty

rest

node.js

express

body-parser