server2.js

const path = require("path");
const fs = require("fs");
const http = require("http");
const url = require("url");
const mime = require("mime");

function readStaticFile(res, pathName) {
  const mimeType = mime.getType(pathName);

  if (!mimeType) return;

  fs.readFile(path.resolve(__dirname, `./${pathName}`), (err, data) => {
    if (err) {
      res.writeHead(404, { "Content-Type": "text/plain" });
      res.write("404 NOT FOUND");
      res.end();
    } else {
      res.writeHead(200, { "Content-Type": mimeType });
      res.write(data);
      res.end();
    }
  });
}

const server = http.createServer(function (req, res) {
  // http://nodejs.cn/api/url.html
  let pathName = url.parse(req.url).pathname;
  if (pathName === "/") pathName = "index.html";

  res.setHeader("Access-Control-Allow-Origin", "*");
  // res.writeHead(200, { "Content-Type": mime.getType(pathName) });

  // 读取静态文件
  readStaticFile(res, pathName);
});

server.listen(5000, () => {
  console.log("Server running at http://127.0.0.1:5000/");
});