• Node.js_express_中间件 middleware_登录/注册实例源代码

    静态资源：

    都写死了的资源，如 css，html

     

    解析规则：

    所有路由和中间件都在一个数组中，js 引擎会按照代码先后顺序添加路由和中间件

    当请求发送到服务器时，服务器获取当前的请求信息（请求方式、请求路由路径）

    遍历数组，找到第一个匹配（请求路由路径和请求方式必须完全一致）到的路由或者中间件，执行其回调函数

    意味着： 声明多个同名路由时，始终解析第一个

    如果没找到，返回一个状态码为 404 的响应， Cannot GET / xxx    或者  Cannot POST / xxx

     

    中间件 middleware

    当有多个路由做同一件事情，这时就会交给中间件去完成

    本质上就是一个函数 (request, response, next)=>{}

    express 框架 实现服务器    完全是由 路由 和 中间件 组成的

    需要调用 next() 方法，才会接下来处理下面的中间件或者路由，否则卡住了

    • app.use(express.static('./public'));    //默认调用next

    接受请求，通过分析参数，找到了 public 对应资源就返回响应

    将该文件夹下所有静态资源暴露出去

    例如： 文件夹有 

    public/index.html

    public/css/index.css

    就可在浏览器访问

    127.0.0.1:3000/index.html

    127.0.0.1:3000/css/index.css

    • app.use(express.urlencoded({extended: true}));    //默认调用next

    解析 请求体 数据，结果数据挂载到 req.body 上

    • 实例分析： 
    • // 1. 导入 express 模块
const express =  require('express');

// 2. 创建 app 应用对象
const app = express();

// 3. 写业务逻辑：处理请求，返回响应

          /**** 配置内置 中间件 (express 自带) ****/
    // 将该文件夹下所有静态资源暴露出去
          // 接受请求，通过分析参数，找到了       public 对应资源就返回响应
    app.use(express.static('./public'));    // public 下有 index.html css/index.css
    // 可在127.0.0.1：3000/index.html    css/index.css
    
    // 解析请求体数据，结果数据挂载到 req.body 上
    app.use(express.urlencoded());         // 默认调用 next()
    /**** 以上两个一般结合使用 ****/

          // 中间件默认能接收并处理所有请求
          // 需要调用 next() 方法，才会接下来处理下面的中间件或者路由，否则卡住了
          app.use((request, response, next)=>{
              next();    // 调用下一个中间件或者路由
          });
          /**************************************/      

        // route 路由的组成： app.请求方式('/路由路径', 句柄函数);
        app.get('/login', (request, response)=>{
        console.log(request.body);
        response.send('Login Page Response!');
    });

    app.post('/register', (request, response)=>{
        console.log(request.query);
        response.send('Register Page Response!');
    });

// 4. 监听端口号：一个端口号 有且只能运行 一个程序
app.listen(3000, err=>console.log(err?err:'服务器启动成功 :  http://127.0.0.1:3000'));

     

    登录/注册实例

    • 什么时候用 get ，什么时候用 post？

    get 请求 只有 请求字符串，

    post 请求 既有 请求字符串，又有 表单数据 form-data

    1. 凡是涉及到用户的隐私数据，就用 post，相对安全

    2. 其他就用 get

    • 业务逻辑

    1. 导入 exoress 框架

    2. 注册路由

    由于默认访问不到静态资源，所以1引入中间件，暴露静态资源

    默认不能解析 请求体 ，则2引入中间件，解析 请求体 数据（优先级低于上一中间件，避免多余分析）

    ① 获取用户提交的表单数据        req.body

    ② 对数据进行正则验证（验证数据的规范）    

    ③ 检查用户名是否存在

    连接数据库

    User.findOne();

    ④ 保存在数据库中        

    User.create();

    ⑤ 无论 失败/成功 都要返回

    3. 登录路由

    4. 设置端口号，启动服务器监听

    • 初次尝试，源代码

    package.json

    • {
  "name": "node_express",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "express": "^4.16.4",
    "mongoose": "^5.4.0"
  }
}

    /route/register.html

    • <!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8"/>
        <title>用户注册</title>
        
        <link rel="stylesheet" type="text/css" href="css/index.css"/>
    </head>
    
    <body>
        <div id="outer_box" class="register">
            <h2>用户注册</h2>
            <form action="http://localhost:3000/register" method="post">
                <div class="clothes">
                    <label for="input_name">用&nbsp;户&nbsp;名</label>
                    <input id="input_name" type="text" name="user_name" placeholder="请输入用户名" />
                </div>
        
                <div class="clothes">
                    <label for="input_pwd">密&nbsp;&nbsp;&nbsp;码</label>
                    <input id="input_pwd" type="password" name="user_pwd" placeholder="请输入密码" />
                </div>
                
                <div class="clothes">
                    <label for="input_repwd">确认密码</label>
                    <input id="input_repwd" type="password" name="user_repwd" placeholder="请再次输入密码" />
                </div>
                
                <div class="clothes">
                    <label for="input_email">注册邮箱</label>
                    <input id="input_email" type="text" name="user_email" placeholder="请输入邮箱地址" />
                </div>
                
                <div class="clothes">
                    <button class="register btn" type="submit">注册</button>
                    <a class="btn" href="http://localhost:3000/login">
                        <button type="button">登录</button>
                    </a>
                </div>
            </form>
        </div>
        
        <script type="text/javascript" src="../index.js"></script>
    </body>
</html>

    /route/login.html

    • <!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8"/>
        <title>用户登录</title>
        
        <link rel="stylesheet" type="text/css" href="css/index.css"/>
    </head>
    
    <body>
        <div id="outer_box" class="login">
            <h2>用户登录</h2>
            <form action="http://localhost:3000/login" method="post">
                <div class="clothes">
                    <label for="input_name">用&nbsp;户&nbsp;名</label>
                    <input id="input_name" type="text" name="user_name" placeholder="请输入用户名" />
                </div>
                
                <div class="clothes">
                    <label for="input_pwd">密&nbsp;&nbsp;&nbsp;码</label>
                    <input id="input_pwd" type="password" name="user_pwd" placeholder="请输入密码" />
                </div>
                
                <div class="clothes">
                    <a class="btn" href="http://localhost:3000/register">
                        <button type="button">注册</button>
                    </a>
                    <button class="login btn" type="submit">登录</button>
                </div>
            </form>
        </div>
        
    </body>
</html>

    /route/css/index.css

    • body {
    width: 100%;
    height: 100%;
    
    color: #000;
    background: #b9c2a4;
    background-size: cover; /* 指定背景图片大小 */
}

/*************************************************/
#outer_box {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #1a45c3;
}

#outer_box.login {
    color: #9e098b;
}

#outer_box.register {
    color: #1a45c3;
}

#outer_box>h2{
    padding-bottom: 40px;
    margin-left: -50px;
}

.clothes {
    width: 260px;
    display: flex;
    justify-content: space-between;
    margin: 20px 0;
    font-size: 18px;
    line-height: 32px;
}

.clothes>label{
    width: 80px;
    text-align: center;
}

.clothes>input{
    width: 170px;
    height: 32px;
}

button {
    width: 100%;
    height: 100%;
    
    font-size: 16px;
    background-color: #c4ceda;
    cursor: pointer;
}

.clothes .btn{
    width: 64px;
    height: 32px;
    margin: 0 20px;
}

.clothes button.register{
    background-color: #1a45c3;
    color: #fff;
}

.clothes button.login{
    background-color: #9e098b;
    color: #fff;
}

    /db/connectDB.js

    • const mongoose = require('mongoose');

const promiseConnect = new Promise((resolve, reject)=>{
    mongoose.connect('mongodb://localhost:27017/user_database', {useNewUrlParser:true})
    mongoose.connection.once('open', err=>{
        if(err){
            console.log(err);
            reject(err);
        }else{
            resolve(true);
        };
    });
});

module.exports = promiseConnect;

    /db/tableModel.js

    • const mongoose = require('mongoose');

const Schema = mongoose.Schema;
const studentsSchema = new Schema({
    "userName": {
        "type": String,
        "default": "test"
    },
    "userPassword": {
        "type": String,
        "default": "123456"
    },
    "userEmail": {
        "type": String,
        "unique": true
    },
    "createTime": {
        "type": Date,
        "default": Date.now()
    }
});

const studentsModel = mongoose.model("user_info", studentsSchema);

module.exports = studentsModel;

    index.js

    • const express =  require('express');
const promiseConnect = require('./db/connectDB.js');
const userInfoModel = require('./db/tableModel.js');

promiseConnect.then(async result=>{
    if(result){
        isConeected = true;
    };
}).catch(err=>console.log(err));

const app = express();

/*********************** 中间件 **********************/
// 暴露路由 login.html register.html
app.use(express.static('route'));    // 默认调用 next();

// 将 用户输入的数据 挂载到 请求体 request.body  上
app.use(express.urlencoded({extended: true}));    // 默认调用 next();

/************************ get ***********************/
app.get('/', (request, response)=>{
    response.redirect('./login.html');
});

app.get('/login', (request, response)=>{
    response.redirect('./login.html');
});

app.get('/register', (request, response)=>{
    response.redirect('./register.html');
});

/************************ post ***********************/

let isConeected = false;
let canBeCreated = false;
let createSuccess = false;

let logined = false;

app.post('/register', async (request, response)=>{
    if(isConeected){
        let uName = request.body['user_name'];
        let uPwd = request.body['user_pwd'];
        let urePwd = request.body['user_repwd'];
        let uEmail = request.body['user_email'];
        userInfo = {
            "userName": uName,
            "userPassword": uPwd,
            "userEmail": uEmail
        };
        
        canBeCreated = false;
        createSuccess = false;
        someThingWrong = false;
        
        console.log('
------------------注册--------------------');
        if(urePwd !== uPwd){
            console.log("(づ╥﹏╥)づ[两次输入不一致`]");
            response.redirect('./register.html');
            return ;
        }else if(!(/^[a-zA-Z][a-zA-Z0-9_]{5,20}$/.test(uName))){
            console.log("(づ╥﹏╥)づ[用户名不合法`]");
            response.redirect('./register.html');
            return ;
        }else if(!(/^[a-zA-Z0-9_]{6,20}$/.test(uPwd))){
            console.log("(づ╥﹏╥)づ[密码不合法`]");
            response.redirect('./register.html');
            return ;
        }else if(!(/^w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*$/.test(uEmail))){
            console.log('(づ╥﹏╥)づ[邮箱不合法`]');
            response.redirect('./register.html');
            return ;
        }else{
            canBeCreated = true;
            const badEmail = await userInfoModel.findOne({"userEmail": uEmail});
            if(badEmail){
                console.log('(づ╥﹏╥)づ[邮箱已存在`]');
                response.redirect('./register.html');
                return ;
            };
        };
        
        const fond = await userInfoModel.findOne({"userName": uName});
        if(!fond && canBeCreated){
            await userInfoModel.create(userInfo);
            createSuccess = true;
            console.log('(o゜▽゜)o☆[注册成功!]☆');
        }else{
            console.log('(づ╥﹏╥)づ[用户名已存在`]');
        };
    };
    
    if(createSuccess){
        response.redirect('./login.html');
    }else{
        response.redirect('./register.html');
    };
});

app.post('/login',async (request, response)=>{
    if(isConeected){
        let uName = request.body['user_name'];
        let uPwd = request.body['user_pwd'];
        userInfo = {
            "userName": uName,
            "userPassword": uPwd
        };
    
        logined = false;
        
        console.log('
------------------登录--------------------');
        if(!(/^[a-zA-Z][a-zA-Z0-9_]{5,20}$/.test(uName))){
            logined = false;
            // 用户名不存在
        }else if(!(/^[a-zA-Z0-9_]{6,20}$/.test(uPwd))){
            logined = false;
            // 密码错误
        };
        
        const findName = await userInfoModel.findOne({"userName": uName});
        const findPwd = await userInfoModel.findOne({"userPassword": uPwd});
        if(findName && findPwd){
            logined = true;
        };
    };
    
    console.log(logined?'(o゜▽゜)o☆[登录成功!]☆':'(づ╥﹏╥)づ[用户名或密码错误`]');
    response.redirect('./login.html');
});

/**************** 监听 3000, 启动服务器 ***************/
app.listen(3000, err=>console.log(err?err:'

服务器已启动: http://localhost:3000
Hunting Happy!'));

     

    改进后，源代码

    package.json

    • {
  "name": "node_express",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "express": "^4.16.4",
    "mongoose": "^5.4.0"
  }
}

    templates/login.html

    • <!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8"/>
        <title>用户登录</title>
        
        <link rel="stylesheet" type="text/css" href="css/index.css"/>
    </head>
    
    <body>
        <div id="outer_box" class="login">
            <h2>用户登录</h2>
            <form action="http://localhost:3000/login" method="post">
                <div class="clothes">
                    <label for="input_name">用&nbsp;户&nbsp;名</label>
                    <input id="input_name" type="text" name="user_name" placeholder="请输入用户名" />
                </div>
                
                <div class="clothes">
                    <label for="input_pwd">密&nbsp;&nbsp;&nbsp;码</label>
                    <input id="input_pwd" type="password" name="user_pwd" placeholder="请输入密码" />
                </div>
                
                <div class="clothes">
                    <a class="btn" href="http://localhost:3000/register">
                        <button type="button">注册</button>
                    </a>
                    <button class="login btn" type="submit">登录</button>
                </div>
            </form>
        </div>
    </body>
</html>

    templates/register.html

    • <!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8"/>
        <title>用户注册</title>
        
        <link rel="stylesheet" type="text/css" href="css/index.css"/>
    </head>
    
    <body>
        <div id="outer_box" class="register">
            <h2>用户注册</h2>
            <form action="http://localhost:3000/register" method="post">
                <div class="clothes">
                    <label for="input_name">用&nbsp;户&nbsp;名</label>
                    <input id="input_name" type="text" name="user_name" placeholder="请输入用户名" />
                </div>
        
                <div class="clothes">
                    <label for="input_pwd">密&nbsp;&nbsp;&nbsp;码</label>
                    <input id="input_pwd" type="password" name="user_pwd" placeholder="请输入密码" />
                </div>
                
                <div class="clothes">
                    <label for="input_repeat_pwd">确认密码</label>
                    <input id="input_repeat_pwd" type="password" name="user_repeat_pwd" placeholder="请再次输入密码" />
                </div>
                
                <div class="clothes">
                    <label for="input_email">注册邮箱</label>
                    <input id="input_email" type="text" name="user_email" placeholder="请输入邮箱地址" />
                </div>
                
                <div class="clothes">
                    <button class="register btn" type="submit">注册</button>
                    <a class="btn" href="http://localhost:3000/login">
                        <button type="button">登录</button>
                    </a>
                </div>
            </form>
        </div>
    </body>
</html>

    templates/css/index.css

    • @charset "utf-8";

* {
    margin: 0px;
    padding: 0px;
}

.clearfix {
    zoom: 1;
}

.clearfix:before,
.clearfix:after {
    content: "";
    display: table;
    clear: both;
}

.unSelectedAble {
    /* 内容不可以被选中 */
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

body {
    width: 100%;
    height: 100%;
    
    color: #000;
    background: #b9c2a4;
    background-size: cover; /* 指定背景图片大小 */
}

/*************************************************/
#outer_box {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #1a45c3;
}

#outer_box.login {
    color: #9e098b;
}

#outer_box.register {
    color: #1a45c3;
}

#outer_box>h2{
    padding-bottom: 40px;
    margin-left: -50px;
}

.clothes {
    width: 260px;
    display: flex;
    justify-content: space-between;
    margin: 20px 0;
    font-size: 18px;
    line-height: 32px;
}

.clothes>label{
    width: 80px;
    text-align: center;
}

.clothes>input{
    width: 170px;
    height: 32px;
}

button {
    width: 100%;
    height: 100%;
    
    font-size: 16px;
    background-color: #c4ceda;
    cursor: pointer;
}

.clothes .btn{
    width: 64px;
    height: 32px;
    margin: 0 20px;
}

.clothes button.register{
    background-color: #1a45c3;
    color: #fff;
}

.clothes button.login{
    background-color: #9e098b;
    color: #fff;
}

    db/index.js

    • const mongoose = require('mongoose');

module.exports = new Promise((resolve, reject)=>{
    mongoose.connect('mongodb://localhost:27017/user_database', {useNewUrlParser:true})
    mongoose.connection.once('open', err=>{
        if(err){
            console.log(err);
            reject(err);
        }else{
            resolve('数据库已连接');
        };
    });
});

    models/index.js

    • const mongoose = require('mongoose');

const Schema = mongoose.Schema;
const fieldSchema = new Schema({
    "userName": {
        "type": String,
        "unique": true,
        "required": true
    },
    "userPassword": {
        "type": String,
        "unique": true,
        "required": true
    },
    "userEmail": {
        "type": String,
        "unique": true,
        "required": true
    },
    "createTime": {
        "type": Date,
        "default": Date.now()
    }
});

module.exports = mongoose.model("user_info", fieldSchema);

    index.js

    • const express =  require('express');
const promiseConnect = require('./db');
const userInfoModel = require('./models');

const app = express();

/*********************** 中间件 **********************/
// 暴露路由 login.html register.html
app.use(express.static('templates'));    // 默认调用 next();

// 将 用户输入的数据 挂载到 请求体 request.body  上
app.use(express.urlencoded({extended: true}));    // 默认调用 next();

/************************ get ***********************/
app.get('/', (request, response)=>{
    response.redirect('./login.html');
});

app.get('/login', (request, response)=>{
    response.redirect('./login.html');
});

app.get('/register', (request, response)=>{
    response.redirect('./register.html');
});

/************************ post ***********************/
let logged = false ;
promiseConnect.then(async result=>{
    console.log(result);
    
    app.post('/register', async (request, response)=>{
        const {
            user_name:uName,
            user_pwd:uPwd,
            user_repeat_pwd:urePwd,
            user_email:uEmail,
        } = request.body;    /**** 解构赋值 ****/
        // let uName = request.body['user_name'];
        // let uPwd = request.body['user_pwd'];
        // let urePwd = request.body['user_repeat_pwd'];
        // let uEmail = request.body['user_email'];
        userInfo = {
            "userName": uName,
            "userPassword": uPwd,
            "userEmail": uEmail
        };
        
        let errInfo = {};
        
        if(urePwd !== uPwd){
            errInfo.repeatPassword = '两次输入不一致';
        };
        if(!(/^[a-zA-Z][a-zA-Z0-9_]{5,20}$/.test(uName))){
            errInfo.name = '用户名不合法';
        };
        if(!(/^[a-zA-Z0-9_]{6,20}$/.test(uPwd))){
            errInfo.password = '密码不合法';
        };
        if(!(/^w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*$/.test(uEmail))){
            errInfo.email = '邮箱不合法';
        };
        
        const badEmail = await userInfoModel.findOne({"userEmail": uEmail});
        if(badEmail){
            errInfo.emailRegistered = '邮箱已被注册';
        };
        
        if(errInfo.repeatPassword || errInfo.name || errInfo.password || errInfo.email){
            response.send(errInfo);
            return;
        };
        
        const fond = await userInfoModel.findOne({"userName": uName});
        if(fond){
            response.send({"error":'用户名已被注册'});
        }else{
            await userInfoModel.create(userInfo);
            response.send({"success":'注册成功'});
        };
    });
    
    app.post('/login',async (request, response)=>{
        logged = false;
        let uName = request.body['user_name'];
        let uPwd = request.body['user_pwd'];
        userInfo = {
            "userName": uName,
            "userPassword": uPwd
        };
        
        if(!(/^[a-zA-Z][a-zA-Z0-9_]{5,20}$/.test(uName))){
            logged = false;    // 用户名不存在
        }else if(!(/^[a-zA-Z0-9_]{6,20}$/.test(uPwd))){
            logged = false;    // 密码错误
        };
        
        const findName = await userInfoModel.findOne({"userName": uName});
        const findPwd = await userInfoModel.findOne({"userPassword": uPwd});
        if(findName && findPwd){
            logged = true;
        };
        
        response.send(logged?{"success":'登录成功'}:{"error":'用户名或密码错误'});
    });
}).catch(err=>console.log(err));

/**************** 端口号 3000, 启动服务器 ***************/
app.listen(3000, err=>console.log(err?err:'

服务器已启动: http://localhost:3000
Hunting Happy!'));

     

    --------小尾巴 ________一个人欣赏-最后一朵颜色的消逝-忠诚于我的是·一颗叫做野的心.决不受人奴役.怒火中生的那一刻·终将结束...
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  • 原文地址：https://www.cnblogs.com/tianxiaxuange/p/10157205.html
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