使用nodejs来回发送文件

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

const server = http.createServer((req, res) => {
  // 处理请求
});

const server = http.createServer((req, res) => {
  if (req.url === '/upload' && req.method === 'POST') {
    // 处理文件上传
  } else if (req.url === '/download' && req.method === 'GET') {
    // 处理文件下载
  } else {
    // 处理其他请求
  }
});

const server = http.createServer((req, res) => {
  if (req.url === '/upload' && req.method === 'POST') {
    const fileStream = fs.createWriteStream('uploaded_file.txt');
    req.pipe(fileStream);
    fileStream.on('finish', () => {
      res.statusCode = 200;
      res.end('File uploaded successfully');
    });
  } else {
    // 处理其他请求
  }
});

const server = http.createServer((req, res) => {
  if (req.url === '/download' && req.method === 'GET') {
    const fileStream = fs.createReadStream('uploaded_file.txt');
    fileStream.pipe(res);
    fileStream.on('error', (err) => {
      res.statusCode = 404;
      res.end('File not found');
    });
  } else {
    // 处理其他请求
  }
});