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

时间  2019-11-08
标签 node.js node express 中间件 middleware 登陆 注册 实例 源代码 栏目 Node.js 繁體版
原文   原文链接

静态资源： javascript

都写死了的资源，如 css，htmlcss

 

解析规则：html

全部路由和中间件都在一个数组中，js 引擎会按照代码前后顺序添加路由和中间件java

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）node

遍历数组，找到第一个匹配（请求路由路径和请求方式必须彻底一致）到的路由或者中间件，执行其回调函数web

意味着： 声明多个同名路由时，始终解析第一个mongodb

若是没找到，返回一个状态码为 404 的响应， Cannot GET / xxx    或者  Cannot POST / xxx数据库

 

中间件 middlewareexpress

当有多个路由作同一件事情，这时就会交给中间件去完成json

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

express 框架 实现服务器    彻底是由 路由 和 中间件 组成的

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

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

接受请求，经过分析参数，找到了 public 对应资源就返回响应

将该文件夹下全部静态资源暴露出去

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. 建立 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) ****/ // 将该文件夹下全部静态资源暴露出去
     // 接受请求，经过分析参数，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()  /**** 以上两个通常结合使用 ****/

     // 中间件默认能接收并处理全部请求
     // 须要调用 next() 方法，才会接下来处理下面的中间件或者路由，不然卡住了
     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'));

 

登陆/注册实例

  • 何时用 get ，何时用 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. 其余就用 get

  • 业务逻辑

1. 导入 exoress 框架

2. 注册路由

因为默认访问不到静态资源，因此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

链接数据库

User.findOne();

④ 保存在数据库中        

User.create();

⑤ 不管 失败/成功 都要返回

3. 登陆路由

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">登陆</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>用户登陆</title>
        
        <link rel="stylesheet" type="text/css" href="css/index.css"/>
    </head>
    
    <body>
        <div id="outer_box" class="login">
            <h2>用户登陆</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">登陆</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('\n------------------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+)*$/.test(uEmail))){ console.log('(づ╥﹏╥)づ[邮箱不合法`]'); response.redirect('./register.html'); return ; }else{ canBeCreated = true; const badEmail = await userInfoModel.findOne({"userEmail": uEmail}); if(badEmail){ console.log('(づ╥﹏╥)づ[邮箱已存在`]'); response.redirect('./register.html'); return ; }; }; const fond = await userInfoModel.findOne({"userName": uName}); if(!fond && canBeCreated){ await userInfoModel.create(userInfo); createSuccess = true; console.log('(o゜▽゜)o☆[注册成功!]☆'); }else{ console.log('(づ╥﹏╥)づ[用户名已存在`]'); }; }; if(createSuccess){ response.redirect('./login.html'); }else{ response.redirect('./register.html'); }; }); app.post('/login',async (request, response)=>{ if(isConeected){ let uName = request.body['user_name']; let uPwd = request.body['user_pwd']; userInfo = { "userName": uName, "userPassword": uPwd }; logined = false; console.log('\n------------------登陆--------------------'); if(!(/^[a-zA-Z][a-zA-Z0-9_]{5,20}$/.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☆[登陆成功!]☆':'(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:'\n\n服务器已启动: http://localhost:3000\nHunting 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>用户登陆</title> <link rel="stylesheet" type="text/css" href="css/index.css"/> </head> <body> <div id="outer_box" class="login"> <h2>用户登陆</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">登陆</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">登陆</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 {
    /* 内容不能够被选中 */ -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('数据库已链接'); }; }); });

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":'登陆成功'}:{"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:'\n\n服务器已启动: http://localhost:3000\nHunting Happy!'));
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