如何允许用户使用node js下载文件？

const http = require('http');
const fs = require('fs');

const server = http.createServer((req, res) => {
  if (req.url === '/download') {
    const filePath = '/path/to/file'; // 替换为实际文件路径

    fs.readFile(filePath, (err, data) => {
      if (err) {
        res.statusCode = 500;
        res.end('Internal Server Error');
      } else {
        res.setHeader('Content-Type', 'application/octet-stream');
        res.setHeader('Content-Disposition', 'attachment; filename=file.txt');
        res.end(data);
      }
    });
  } else {
    res.statusCode = 404;
    res.end('Not Found');
  }
});

server.listen(3000, () => {
  console.log('Server is running on port 3000');
});