用 Node.js 的 http 模块创建最简单的 Web 服务器

1. 创建最简单的 Web 服务器

const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('Hello World!');
});

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

2. req 请求对象

const http = require('http');

const server = http.createServer((req, res) => {
  console.log(req.method); // 请求方法
  console.log(req.url); // 请求路径
  console.log(req.headers); // 请求头
  console.log(req.body); // 请求体

  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('Hello World!');
});

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

3. res 响应对象

const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.write('Hello');
  res.end('World!');
});

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

4. 根据不同的 url 响应不同的 html 内容

const http = require('http');

const server = http.createServer((req, res) => {
  if (req.url === '/') {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.end('<h1>Hello World!</h1>');
  } else if (req.url === '/about') {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.end('<h1>About Page</h1>');
  } else {
    res.writeHead(404, { 'Content-Type': 'text/html' });
    res.end('<h1>404 Not Found</h1>');
  }
});

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