post-form-server.js

const http = require('http');                                                                                                                                                     

const PORT = 3000;

const server = http.createServer((req, res) => {
    if (req.method !== 'POST') {
        return res.end('');
    }

    console.log('\nheader:');
    console.log(JSON.stringify(req.headers));

    const buffers = [];
    let bufferLength = 0;

    req.on('data', data => {
        bufferLength += data.length;
        buffers.push(data);
    });

    req.on('end', () => {
        console.log("body:");
        const body = Buffer.concat(buffers, bufferLength);
        if (req.headers['content-type'] === 'x-www-form-urlencoded') {
            const params = body.toString().replace(/\s/g, '').split('&').sort();
            params.forEach(item => console.log(decodeURIComponent(item).replace(/\s/g, '')));
        }
        else {
            try { console.log(JSON.parse(body.toString())); }
            catch (e) { console.log(e, body); }
        }
        res.end('');
    });
});

server.listen(PORT);
console.log('server started. listening on', PORT);