第6章 HTTP模块

基本使用

创建web服务器

// 1.导入 http 模块
const http = require('http');
// 2.创建 web 服务器实例
const server = http.createServer();
// 3.为服务器实例绑定 request 事件，监听客户端的请求
server.on('request', (req, res) => {
    console.log('Someone visit our web server');
});
// 4.启动服务器
server.listen(80, ()=> {
    console.log('server running at http://127.0.0.1');
});

req 请求对象

req 请求对象用于访问与客户端相关的数据或属性

server.on('request',(req) => {
    // req.url为访问的路径
    // req.method为发送请求的方法
    const url = req.url;
    const method = req.method;
    const str = `Your request url is ${url},and request method is ${method}`;
    console.log(str);
});

res 响应对象

res 响应对象用于访问与服务器相关的数据或属性

server.on('request', (req, res) => {
    const url = req.url;
    const method = req.method;
    const str = `Your request url is ${url},and request method is ${method}`;
    console.log(str);
    // 解决中文乱码：将响应头的 Content-Type 的值设置为 text/html；charset=utf-8
    res.setHeader('Content-Type', 'text/html; charset=utf-8',)
    // 通过 res.end 方法返回内容
    // res.end(str);
    res.end("你好")
});

简单封装

入口文件

// bin/www.js
const http = require('http');
const serverHandle = require('../app');

const PORT = 8000;
const server = http.createServer(serverHandle);

server.listen(PORT, () => {
  console.log('Server is running in http://localhost:8080');
});

处理 query

const querystring = require('querystring');
const query = querystring.parse(url.split('?')[1]);

处理 body

let body = '';
req.on('data', chunk => {
  body += chunk.toString();
})
req.on('end', () => {
  resData.postData = JSON.parse(postData);
  res.end(JSON.stringify(resData));
})

处理路由

const handleUserRouter = require('./src/router/user');

// 处理 user 路由
const userData = handleUserRouter(req, res);
if (userData) {
  res.end(JSON.stringify(userData));
  return;
}

处理 404

res.writeHead(404, { 'Content-type': 'text/plain' });
res.write('404 Not Found\n');
res.end();

Model

// src/model/resModel.js
class BaseModel {
  constructor(data, message) {
    if (typeof data === 'string') {
      this.message = data;
      data = null;
      message = null;
    }
    if (data) {
      this.data = data;
    }
    if (message) {
      this.message = message;
    }
  }
}

class SuccessModel extends BaseModel {
  constructor(data, message) {
    super(data, message);
    this.errno = 0;
  }
}

class ErrorModel extends BaseModel {
  constructor(data, message) {
    super(data, message);
    this.errno = -1;
  }
}

module.exports = {
  SuccessModel,
  ErrorModel
};

Router

const { login } = require('../controller/user');
const { SuccessModel, ErrorModel } = require('../model/resModel');

const handleUserRouter = (req, res) => {
  const { method } = req;

  // 登录
  if (method === 'POST' && req.path === '/api/user/login') {
    const { username, password } = req.body;
    const result = login(username, password);
    return result.then((data) => {
      if (data.username) {
        return new SuccessModel();
      } else {
        return new ErrorModel('登录失败');
      }
    });
  }
};

module.exports = handleUserRouter;

Controller

const { exec } = require('../db/mysql');

const login = (username, password) => {
  const sql = `select username, realname from users where username=${username} and password=${password}`;
  return exec(sql).then((rows) => rows[0] || {});
};

module.exports = { login };