你可以使用querystring模块:

var qs = require('querystring');

function (request, response) {
    if (request.method == 'POST') {
        var body = '';

        request.on('data', function (data) {
            body += data;

            // Too much POST data, kill the connection!
            // 1e6 === 1 * Math.pow(10, 6) === 1 * 1000000 ~~~ 1MB
            if (body.length > 1e6)
                request.connection.destroy();
        });

        request.on('end', function () {
            var post = qs.parse(body);
            // use post['blah'], etc.
        });
    }
}

现在，例如，如果你有一个名为age的输入字段，你可以使用变量post访问它:

console.log(post.age);

限制POST大小，避免淹没你的节点应用。 有一个很棒的原始模块，适合表达和连接，可以帮助您限制大小和长度的请求。

参考:https://nodejs.org/en/docs/guides/anatomy-of-an-http-transaction/

let body = [];
request.on('data', (chunk) => {
  body.push(chunk);
}).on('end', () => {
  body = Buffer.concat(body).toString();
  // at this point, `body` has the entire request body stored in it as a string
});

对于任何想知道如何在不安装web框架的情况下完成这个微不足道的任务的人，我设法把它放在一起。几乎没有生产准备，但它似乎工作。

function handler(req, res) {
    var POST = {};
    if (req.method == 'POST') {
        req.on('data', function(data) {
            data = data.toString();
            data = data.split('&');
            for (var i = 0; i < data.length; i++) {
                var _data = data[i].split("=");
                POST[_data[0]] = _data[1];
            }
            console.log(POST);
        })
    }
}

Node.js 18的现代异步方式，零依赖:

server.mjs:

import { createServer } from 'node:http';

const rawReqToString = async (req) => {
    const buffers = [];
    for await(const chunk of req){
        buffers.push(chunk);
    }
    return Buffer.concat(buffers).toString();
};

const server = createServer(async (req, res) => {
    const object = JSON.parse(await rawReqToString(req));
    ...
});

server.listen(3000, 'localhost', () => {
    console.log(`The server is running.`);
})

如果你使用Express (Node.js的高性能、高级web开发)，你可以这样做:

HTML:

<form method="post" action="/">
    <input type="text" name="user[name]">
    <input type="text" name="user[email]">
    <input type="submit" value="Submit">
</form>

API客户端:

fetch('/', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json'
    },
    body: JSON.stringify({
        user: {
            name: "John",
            email: "john@example.com"
        }
    })
});

Node.js:(自Express v4.16.0起)

// Parse URL-encoded bodies (as sent by HTML forms)
app.use(express.urlencoded());

// Parse JSON bodies (as sent by API clients)
app.use(express.json());

// Access the parse results as request.body
app.post('/', function(request, response){
    console.log(request.body.user.name);
    console.log(request.body.user.email);
});

Node.js:(对于Express <4.16.0)

const bodyParser = require("body-parser");

/** bodyParser.urlencoded(options)
 * Parses the text as URL encoded data (which is how browsers tend to send form data from regular forms set to POST)
 * and exposes the resulting object (containing the keys and values) on req.body
 */
app.use(bodyParser.urlencoded({
    extended: true
}));

/**bodyParser.json(options)
 * Parses the text as JSON and exposes the resulting object on req.body.
 */
app.use(bodyParser.json());

app.post("/", function (req, res) {
    console.log(req.body.user.name)
});