前面一有写到一篇Node.js+Express构建网站简单示例https://cloud.tencent.com/developer/article/1020656
这篇还是用以前的例子, 用Node.js+Koa2构建
Koa: https://github.com/koajs/koa
Koa就不多介绍了,前面也写过Express,同一个团队打造,前面也过express文章,对比着看,自然可以看出些优点!
创建数据库
CREATE DATABASE IF NOT EXISTS nodesample CHARACTER SET UTF8;
USE nodesample;
SET FOREIGN_KEY_CHECKS=0;
DROP TABLE IF EXISTS `userinfo`;
CREATE TABLE `userinfo` (
`Id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
`UserName` varchar(64) NOT NULL COMMENT '用户名',
`UserPass` varchar(64) NOT NULL COMMENT '用户密码',
PRIMARY KEY (`Id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户信息表';
创建Koa2项目
安装koa-generator: https://github.com/17koa/koa-generator
npm install -g koa-generator
安装成功后下图(版本:1.1.16)
然后创建Koa2项目,安装相关依赖项
cd 工作目录
koa2 项目名
cd 项目目录 && npm install
安装项目其它需要包
1.安装使用MySQL需要的包
npm install --save mysql
没有使用过的可以看我以前写的相关操作文章:https://cloud.tencent.com/developer/article/1020645
2.安装ejs(koa2默认为jade,我习惯使用ejs)
npm install --save ejs
没有使用过的可以看我以前写的相关操作文章:https://cloud.tencent.com/developer/article/1020633
3.安装Session存储相关包(存储到redis)
npm install koa-session https://github.com/koajs/session
npm install --save koa-session
koa-session-redis https://github.com/Chilledheart/koa-session-redis
npm install --save koa-session-redis
清除冗余文件并重新规划项目目录
1.删除掉创建项目后自带的views和routes下的文件
2.重新规划项目目录,规划后如下
目录规则解释:
1.新增pub目录:主要为了统一存放"数据访问"、"业务逻辑"、"公共方法文件"、"数据库帮助文件"、"配置文件"等
2.新增pub目录下utils目录:主要为了统一存放类似"公共函数文件"、"返回值文件"、"枚举文件"等公共文件
3.新增pub目录下config目录:主要为了统一存放各种类型的配置文件
4.新增pub目录下db目录:主要为了统一存放各种数据库帮助类,比如:"mysql-helper.js"、"mongo-helper.js"等等
5.新增pub目录下model目录:主要为了统一存放各种数据库各表CURD操作
6.新增pub目录下bll目录:主要为了统一存放各种业务逻辑的具体实现
从上面的图可以看出,我在pub下新建的config目录下新建了一个config.js
这个config.js中将编写“开发环境”和“发布环境”中所需的配置,代码如下
/**
* 配置文件
*/
//发布配置
const production = {
//服务器端口
SERVER_PORT : 3000,
//REDIS配置
REDIS: {
host: 'localhost',
port: 6379,
password: "abcd",
maxAge: 3600000
},
//MYSQL数据库配置
MYSQL: {
host: "localhost",
user: "root",
password: "abcd",
port: "3306",
database: "nodesample",
supportBigNumbers: true,
multipleStatements: true,
timezone: 'utc'
}
}
//开发配置
const development = {
//服务器端口
SERVER_PORT : 3000,
//REDIS配置
REDIS: {
host: 'localhost',
port: 6379,
password: "abcd",
maxAge: 3600000
},
//MYSQL数据库配置
MYSQL: {
host: "localhost",
user: "root",
password: "abcd",
port: "3306",
database: "nodesample",
supportBigNumbers: true,
multipleStatements: true,
timezone: 'utc'
}
}
const config = development
module.exports = config
示例中将有注册、登录功能,先规划好路由,新建routes、views下的相关需要的文件(如项目目录图中文件),并修改app.js文件
const Koa = require('koa')
const app = new Koa()
const views = require('koa-views')
const json = require('koa-json')
const onerror = require('koa-onerror')
const bodyparser = require('koa-bodyparser')
const logger = require('koa-logger')
const config = require('./pub/config/config.js');
const session = require('koa-session');
const RedisStore = require('koa2-session-redis');
const index = require('./routes/index')
const reg = require('./routes/reg')
const login = require('./routes/login')
const logout = require('./routes/logout')
// error handler
onerror(app)
// middlewares
app.use(bodyparser({
enableTypes:['json', 'form', 'text']
}))
app.use(json())
app.use(logger())
app.use(require('koa-static')(__dirname + '/public'))
app.use(views(__dirname + '/views', {
extension: 'ejs'
}))
// logger
app.use(async (ctx, next) => {
const start = new Date()
await next()
const ms = new Date() - start
console.log(`${ctx.method} ${ctx.url} - ${ms}ms`)
})
app.keys = ['Porschev'];
const redis_conf = {
key: 'Porschev',
maxAge: config.REDIS.maxAge,
overwrite: true,
httpOnly: true,
rolling: false,
sign: true,
store: new RedisStore({
host: config.REDIS.host,
port: config.REDIS.port,
password: config.REDIS.password
})
};
app.use(session(redis_conf, app));
// routes
app.use(index.routes(), index.allowedMethods())
app.use(reg.routes(), reg.allowedMethods())
app.use(login.routes(), login.allowedMethods())
app.use(logout.routes(), logout.allowedMethods())
// error-handling
app.on('error', (err, ctx) => {
console.error('server error', err, ctx)
});
app.listen(config.SERVER_PORT, () => {
console.log(`Starting at port ${config.SERVER_PORT}!`)
});
module.exports = app
注意看红色标记修改或增加的部分
1.首先编写一个mysql-helper.js方便以连接池的方式进行操作
const config = require('./../config/config.js')
const mysql = require("mysql")
const pool = mysql.createPool(config.MYSQL)
let query = function(sql, args) {
return new Promise((resolve, reject) => {
pool.getConnection(function(err, connection) {
if (err) {
resolve(err)
} else {
connection.query(sql, args, (err, result) => {
if (err) {
reject(err)
} else {
resolve(result)
}
connection.release()
})
}
})
})
}
module.exports = {
query
}
2.编写数据访问相关方法(model目录下的userinfo.js),如下
const mysqlHelper = require('./../db/mysql-helper.js')
const userinfo = {
/**
* 增加一条数据
* @param {object} args 参数
* @return {object} 结果
*/
async add ( args ) {
let sql = 'INSERT INTO userinfo(UserName, UserPass) VALUES(?, ?)'
let params = [args.username, args.userpass]
let result = await mysqlHelper.query(sql, params)
return result
},
/**
* 根据UserName得到一条数据
* @param {object} args 参数
* @return {object} 结果
*/
async getByUserName( args ){
let sql = 'SELECT Id, UserName, UserPass FROM userinfo WHERE UserName = ?'
let params = [args.username]
let result = await mysqlHelper.query(sql, params)
return result
},
/**
* 根据UserName得到数量
* @param {object} args 参数
* @return {object} 结果
*/
async getCountByUserName( args ){
let sql = 'SELECT COUNT(1) AS UserNum FROM userinfo WHERE UserName = ?'
let params = [args.username]
let result = await mysqlHelper.query(sql, params)
return result
},
}
module.exports = userinfo
3.在写业务逻辑之前先规划好返回值(utils目录下retcode.js)
/*
* 返回码
*/
const RetCode = {
SessionExpired: -1, //session过期
Fail: 0, //失败
Success: 1, //成功
ArgsError: 2, //参数错误
UserExisted: 10, //用户已经存在
UsernameOrPasswordError: 11, //用户名或者密码错误
UserNotExist: 12, //用户不存在
};
module.exports = RetCode
4.编写“登录”、“注册”等业务逻辑(bll下userinfo.js)
const usermodel = require('./../model/userinfo.js')
const retCode = require('./../utils/retcode.js')
const userinfo = {
/**
* 注册
* @param {object} ctx 上下文
* @return {object} 结果
*/
async register ( ctx ) {
let form = ctx.request.body
const args = {
username: form.username,
userpass: form.userpass
}
let result = {
code: retCode.Success,
data: null
}
//验证非空
if(!args.username || !args.userpass){
result.code = retCode.ArgsError
return result
}
//根据用户名得到用户数量
let userNumResult = await usermodel.getCountByUserName(args)
//用户名已被注册
if(userNumResult[0].UserNum > 0){
result.code = retCode.UserExisted
return result
}
//插入注册数据
let userResult = await usermodel.add(args)
if(userResult.insertId <= 0){
result.code = retCode.Fail
return result
}
return result
},
/**
* 登录
* @param {object} ctx 上下文
* @return {object} 结果
*/
async login ( ctx ) {
let form = ctx.request.body
const args = {
username: form.username,
userpass: form.userpass
}
let result = {
code: retCode.Success,
data: null
}
//验证非空
if(!args.username || !args.userpass){
result.code = retCode.ArgsError
return result
}
//根据用户名得到用户信息
let userResult = await usermodel.getByUserName(args)
//用户不存在
if(userResult.length == 0){
result.code = retCode.UserNotExist
return result
}
//用户名或密码错误
if(userResult[0].UserName != args.username || userResult[0].UserPass != args.userpass){
result.code = retCode.UsernameOrPasswordError
return result
}
//将用户ID存入Session中
ctx.session = {id: userResult[0].Id}
return result
},
}
module.exports = userinfo
1.views目录下reg.ejs
<html>
<head>
<title>Nodejs学习笔记(十五)--- Node.js + Koa2 构建网站简单示例</title>
</head>
<body>
<h1><%= title %></h1>
登录名:<input type="text" id="txtUserName" maxlength="20" />
<br/>
<br/>
密码:<input type="password" id="txtUserPwd" maxlength="12" />
<br/>
<br/>
密码:<input type="password" id="txtUserRePwd" maxlength="12" />
<br/>
<br/>
<input type="button" id="btnSub" value="注册" />
</body>
</html>
<script src="/javascripts/jquery-1.11.2.min.js" type="text/javascript"></script>
<script src="/javascripts/md5.js" type="text/javascript"></script>
<script type="text/javascript">
$(function(){
$('#btnSub').on('click', function(){
var $txtUserName = $('#txtUserName'),
txtUserNameVal = $.trim($txtUserName.val()),
$txtUserPwd = $('#txtUserPwd'),
txtUserPwdVal = $.trim($txtUserPwd.val()),
$txtUserRePwd = $('#txtUserRePwd'),
txtUserRePwdVal = $.trim($txtUserRePwd.val());
if(txtUserNameVal.length == 0){
alert('用户名不能为空');
return false;
}
if(txtUserPwdVal.length == 0){
alert('密码不能为空');
return false;
}
if(txtUserRePwdVal.length == 0){
alert('重复密码不能为空');
return false;
}
if(txtUserPwdVal != txtUserRePwdVal){
alert('两次密码不一致');
return false;
}
$.ajax({
url: '/reg',
type: 'POST',
dataType: 'json',
data: {
username: txtUserNameVal,
userpass: hex_md5(txtUserPwdVal)
},
beforeSend: function (xhr) {},
success: function (res) {
if (res != null && res.code) {
var retVal = parseInt(res.code);
switch (retVal) {
case 2:
alert('输入有误');
break;
case 0:
alert('注册失败');
break;
case 1:
alert('注册成功!');
location.href = '/login'
break;
case 10:
alert('用户已注册');
break;
}
}
else {
alert('操作失败');
}
},
complete: function (XMLHttpRequest, textStatus) {},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert('操作失败');
}
});
})
});
</script>
2.routes目录下reg.js
const router = require('koa-router')()
const userBll = require('./../pub/bll/userinfo.js')
const title = '注册'
router.prefix('/reg')
router.get('/', async (ctx, next) => {
await ctx.render('reg', { title })
})
router.post('/', async (ctx, next) => {
let result = await userBll.register(ctx)
ctx.body = result;
})
module.exports = router
1.views目录下login.ejs
<html>
<head>
<title>Nodejs学习笔记(十五)--- Node.js + Koa2 构建网站简单示例</title>
</head>
<body>
<h1><%= title %></h1>
登录名:<input type="text" id="txtUserName" maxlength="20" />
<br/>
<br/>
密码:<input type="password" id="txtUserPwd" maxlength="12" />
<br/>
<br/>
<input type="button" id="btnSub" value="登录" />
</body>
</html>
<script src="/javascripts/jquery-1.11.2.min.js" type="text/javascript"></script>
<script src="/javascripts/md5.js" type="text/javascript"></script>
<script type="text/javascript">
$(function(){
$('#btnSub').on('click', function(){
var $txtUserName = $('#txtUserName'),
txtUserNameVal = $.trim($txtUserName.val()),
$txtUserPwd = $('#txtUserPwd'),
txtUserPwdVal = $.trim($txtUserPwd.val());
if(txtUserNameVal.length == 0){
alert('用户名不能为空');
return false;
}
if(txtUserPwdVal.length == 0){
alert('密码不能为空');
return false;
}
$.ajax({
url: '/login',
type: 'POST',
dataType: 'json',
data: {
username: txtUserNameVal,
userpass: hex_md5(txtUserPwdVal)
},
beforeSend: function (xhr) {},
success: function (res) {
if (res != null && res.code) {
var retVal = parseInt(res.code);
switch (retVal) {
case 2:
alert('输入有误');
break;
case 0:
alert('登录失败');
break;
case 1:
alert('登录成功!');
location.href = '/'
break;
case 11:
alert('用户名或者密码错误');
break;
case 12:
alert('用户不存在');
break;
}
}
else {
alert('操作失败');
}
},
complete: function (XMLHttpRequest, textStatus) {},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert('操作失败');
}
});
})
});
</script>
2.routes目录下login.js
const router = require('koa-router')()
const userBll = require('./../pub/bll/userinfo.js')
const title = '登录'
router.prefix('/login')
router.get('/', async (ctx, next) => {
await ctx.render('login', { title })
})
router.post('/', async (ctx, next) => {
let result = await userBll.login(ctx);
ctx.body = result;
})
module.exports = router
1.views目录下index.ejs
<html>
<head>
<title>Nodejs学习笔记(十五)--- Node.js + Koa2 构建网站简单示例</title>
</head>
<body>
<h1><%= title %></h1>
<% if(id != null) {%>
<h3>登录用户ID:<%= id %> <a id="btnLogOut" href="javascript:void(0);">安全退出</a></h3>
<% } %>
</body>
</html>
<script src="/javascripts/jquery-1.11.2.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(function(){
$('#btnLogOut').on('click', function(){
if(!confirm('确认要退出吗?')){
return;
}
$.ajax({
url: '/logout',
type: 'POST',
dataType: 'json',
data: {},
beforeSend: function (xhr) {},
success: function (res) {
if (res != null && res.code) {
var retVal = parseInt(res.code);
switch (retVal) {
case 0:
alert('失败');
break;
case 1:
alert('成功!');
location.href = '/login'
break;
}
}
else {
alert('操作失败');
}
},
complete: function (XMLHttpRequest, textStatus) {},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert('操作失败');
}
});
})
});
</script>
2.routes目录下index.js
const router = require('koa-router')()
const title = '首页'
router.get('/', async (ctx, next) => {
//判断登录
if(!ctx.session || !ctx.session.id){
await ctx.redirect('/login')
}else{
const id = ctx.session.id;
await ctx.render('index', { title, id })
}
})
module.exports = router
index.js文件中实现如果不存在session则跳回登录页
1.routes目录下logout.js
const router = require('koa-router')()
const retCode = require('./../pub/utils/retcode.js')
router.prefix('/logout')
router.get('/', async (ctx, next) => {
await ctx.render('logout', {})
})
router.post('/', async (ctx, next) => {
ctx.session = null;
let result = {
code: retCode.Success,
data: null
}
ctx.body = result;
})
module.exports = router
没有去说一些细节API,写这篇主要可以对比 Nodejs学习笔记(七)--- Node.js + Express 构建网站简单示例 来看,完全是一亲的示例,只是这次用的Koa2,方便大家看看Koa2和express写出来的不同
总的来说Koa2还是比较好上手,async、await这个对于有C#语言基础的来说也比较亲切,不用二次理解
可以对比一下express时的各种嵌套回调写法,Koa2写好更优雅、更易阅读
示例有限,其它操作通过官网查找API或github找一些组件来动手试,比如最常用的一些功能:操作cookies、上传文件、session存储到其它介质等
参考资料: https://koa.bootcss.com/
老规矩不放源码,虽然是示例结构,但是尽量按照平常做项目的想法去实现的,有兴趣的动手去搭项目做才会理解一些思路,代码都放在文章中了,有问题留言^_^!