Koa2 从入门到精通二

MySQL

安装 npm install mysql -S
我本地数据库配置

{
    host: 'localhost',
    user: 'root',
    password: '',
    database: 'demo'
}

创建测试数据库，database: demo 和 users用户表

数据库连接配置

conf/db.js，在项目目录下创建conf文件夹，用来做数据连接的配置或其他配置

// 数据库连接配置
const env = process.env.NODE_ENV; // 环境参数

// 配置
let MYSQL_CONF

// 开发环境
if (env === 'dev') {
  // 配置mysql
  MYSQL_CONF = {
    host: 'localhost',
    user: 'root',
    password: '',
    database: 'demo'
  }
}
// 线上环境
if (env === 'production') {
  MYSQL_CONF = {
    host: 'localhost',
    user: 'root',
    password: '',
    database: 'myblog'
  }
}

module.exports = {
    MYSQL_CONF
}

数据库连接以及数据库操作统一定义

在项目目录下创建db文件夹

const mysql = require('mysql');
const {
  MYSQL_CONF
} = require('./../conf/db.js');

// 创建链接对象
const con = mysql.createConnection(MYSQL_CONF)

// 开始链接
con.connect()

// 统一执行 sql 的函数
function exec(sql) {
  const promise = new Promise((resolve, reject) => {
      con.query(sql, (err, result) => {
          if (err) {
              reject(err);
              return
          }
          resolve(result);
      })
  })
  return promise
}

module.exports = {
  exec,
  escape: mysql.escape
}

测试数据库能否连接成功，虽然没有数据，但结果显示正常

数据库操作安全性问题

mysql.escape() 特殊字符转义

xss 预防xss攻击 npm install xss -S

md5密码加密在项目下创建 utils 文件作为工具类

const crypto = require('crypto')

// 密钥
const SECRET_KEY = 'ax_d_milo_280383404.wtf!ob987536j*%1jg-_+ab2'

// md5加密
function md5(content) {
  let md5 = crypto.createHash('md5')
  return md5.update(content).digest('hex')
}

// 加密函数
function genPassword(password) {
  const str = `password=${password}&key=${SECRET_KEY}`
  return md5(str)
}
module.exports = {
  genPassword
}

定义控制器，用来对数据库进一步操作

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

// 用于md5加密
const { genPassword } = require('./../utils/cryp')

// 预防xss攻击
const xss = require('xss')

// 检查用户是否已经注册
const checkIsRegister = async (username) => {
  username = escape(username)
  username = xss(username)
  const sql = `
    SELECT * from users WHERE username=${username}
  `
  const result = await exec(sql)
  if (result.length) {
    // 表示该用户已经注册
    return true
  }
  return false
}

// 注册
const register = async (name, username, password) => {
  name = xss(escape(name))
  username = xss(escape(username))
  password = genPassword(password)
  const sql = `
    INSERT INTO users (name, username, password)
    VALUES (${name}, ${username}, '${password}')
  `
  const result = await exec(sql)
  return {
    id: result.insertId
  }
}

module.exports = {
  checkIsRegister,
  register
}

路由，调用控制器定义的函数，对数据库进行操作，并返回结果

const router = require('koa-router')()
const { checkIsRegister, register } = require('./../controller/users')

router.prefix('/users')

router.post('/register', async function (ctx, next) {
  const { name, username, password } = ctx.request.body
  const isRegister = await checkIsRegister(username)
  if (isRegister) {
    ctx.body = "该用户已被注册"
  } else {
    const registerResult = await register(name, username, password)
    ctx.body = registerResult
  }
})

module.exports = router

自定义数据模型，对返回结果的格式进行统一

// 数据模型
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;
    }
  }
}

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

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

module.exports = {
  SuccessModel,
  ErrorModel
}

const router = require('koa-router')()
const { checkIsRegister, register } = require('./../controller/users')
const { SuccessModel, ErrorModel } = require('./../model/resModel')

router.prefix('/users')

router.post('/register', async function (ctx, next) {
  try {
    const { name, username, password } = ctx.request.body
    const isRegister = await checkIsRegister(username)
    if (isRegister) {
      ctx.body = new ErrorModel('该用户已被注册')
    } else {
      const registerResult = await register(name, username, password)
      ctx.body = new SuccessModel(registerResult, '注册成功')
    }
  }catch {
    ctx.body = new ErrorModel('注册失败')
  }
})

module.exports = router

koa-morgan 进行线上环境日志记录

参考文档
安装 npm install koa-morgan -S
使用，在项目文件下新建logs文件夹

const morgan = require('koa-morgan')
const path = require('path')
const fs = require('fs')
// 开发环境日志记录，生成环境直接在控制台输出
const ENV = process.env.NODE_ENV
if (ENV === 'dev') {
  // dev
  app.use(morgan('dev'))
} else {
  // production
  const logFileName = path.join(__dirname, 'logs', 'access.log')
  const writeStream = fs.createWriteStream(logFileName, {
    flags: 'a'
  })
  app.use(morgan('combined', {
    stream: writeStream
  }));
}

去掉koa-logger npm uninstall koa-logger

const Koa = require('koa')
const app = new Koa()
const json = require('koa-json')
const onerror = require('koa-onerror')
const bodyparser = require('koa-bodyparser')
const morgan = require('koa-morgan')
const path = require('path')
const fs = require('fs')

const index = require('./routes/index')
const users = require('./routes/users')

// error handler
onerror(app)

// middlewares
app.use(bodyparser({
  enableTypes:['json', 'form', 'text']
}))
app.use(json())
app.use(require('koa-static')(__dirname + '/public/'))

// production into logs，dev console.log 
const ENV = process.env.NODE_ENV
if (ENV === 'dev') {
  // dev
  app.use(morgan('dev'))
} else {
  // production
  const logFileName = path.join(__dirname, 'logs', 'access.log')
  const writeStream = fs.createWriteStream(logFileName, {
    flags: 'a'
  })
  app.use(morgan('combined', {
    stream: writeStream
  }));
}

// routes
app.use(index.routes(), index.allowedMethods())
app.use(users.routes(), users.allowedMethods())

// error-handling
app.on('error', (err, ctx) => {
  console.error('server error', err, ctx)
});

module.exports = app

Koa2（二）

Koa2 从入门到精通二

MySQL

koa-morgan 进行线上环境日志记录