Node.js学习笔记 - Node.js+Express开发网站简单示例

2,847 阅读8分钟
原文链接: cloud.tencent.com

目录

  • 前言
  • 新建项目、建立数据库以及其它准备工作
    • 新建express + ejs 项目:sampleEjs
    • 创建数据库
    • 修改package.json文件,安装session和mysql模块
    • 样式和JQuery文件
    • 清理项目冗余文件,并添加监听
  • 规划路由,并新建相关文件
  • 实现登录和注册需要的数据访问方法
  • 注册
  • 登录
  • 首页
  • 安全退出
  • 写在之后

前言

上一篇学习了一些构建网站会用到的一些知识点 http://www.cnblogs.com/zhongweiv/p/nodejs_express_webapp1.html

这一篇主要结合前面讲到的知识,去构建一个较为完整的网站应用程序,对前面学到的一些知道做一个串联加深并灵活运用!

功能主要用MySQL数据库,包括登录、注册、主页三部分;下面就一步步开始吧!

新建项目、建立数据库以及其它准备工作

1.新建express + ejs 项目:sampleEjs

cd 工作目录
express -e sampleEjs
cd sampleEjs && npm install

2.创建数据库(还第四篇数据库一致: http://www.cnblogs.com/zhongweiv/p/nodejs_mysql.html

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';

3.修改package.json文件,安装session和mysql模块

{
  "name": "sampleEjs",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "express": "~4.0.0",
    "static-favicon": "~1.0.0",
    "morgan": "~1.0.0",
    "cookie-parser": "~1.0.1",
    "body-parser": "~1.0.0",
    "debug": "~0.7.4",
    "ejs": "~0.8.5",
    "express-session" : "latest",
    "mysql" : "latest"
  }
}

主要是标红部分(mysql如果是在这篇文章http://www.cnblogs.com/zhongweiv/p/nodejs_mysql.html 中按照我的步骤安装过了的,其实可以不用再安装),然后在cmd中运行

npm install

安装完成后,打开app.js文件,添加如下代码

var express = require('express');
var path = require('path');
var favicon = require('static-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var session = require('express-session');

...      

//这里传入了一个密钥加session id
app.use(cookieParser('Wilson'));
//使用靠就这个中间件
app.use(session({ secret: 'wilson'}));

...

4.样式和JQuery文件

样式:  样式主要使用了bootstrap 3.0.3  https://github.com/twbs/bootstrap/releases/tag/v3.0.3

JQuery:     jquery  1.11.1           http://jquery.com/download/

添加以上文件到项目中,目录结构如下

不在bootstrap包中两个css文件样式如下:

navbar-static-top.css

body {
  min-height: 2000px;
}

.navbar-static-top {
  margin-bottom: 19px;
}

signin.css

body {
  padding-top: 40px;
  padding-bottom: 40px;
  background-color: #eee;
}

.form-signin {
  max-width: 330px;
  padding: 15px;
  margin: 0 auto;
}
.form-signin .form-signin-heading,
.form-signin .checkbox {
  margin-bottom: 10px;
}
.form-signin .checkbox {
  font-weight: normal;
}
.form-signin .form-control {
  position: relative;
  font-size: 16px;
  height: auto;
  padding: 10px;
  -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;
}
.form-signin .form-control:focus {
  z-index: 2;
}
.form-signin input[type="text"] {
  margin-bottom: 10px;
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}
.form-signin input[type="password"] {
  margin-bottom: 10px;
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

5.清理项目冗余文件,并添加监听

删除自带的style.css文件

删除routes目录下user.js文件,并在app.js中删除如下代码

var users = require('./routes/users');

...

app.use('/users', users);

 app.js文件中添加8000端口监听

...
app.listen(8000);
...

到这里,示例环境准备完毕!

规划路由,并新建相关文件

1.路由

首页:/

注册页:/reg

登录页:/login

安全退出:/logout

(红色表示需要新建的)

2.routes目录下新建如下文件

reg.js

login.js

logout.js

3.views目录下新建:

header.ejs

reg.ejs

login.ejs

4.打开app.js文件,添加如下代码

...

var routes = require('./routes/index');
var reg = require('./routes/reg');
var login = require('./routes/login');
var logout = require('./routes/logout');

...

app.use('/', routes);
app.use('/reg', reg);
app.use('/login', login);
app.use('/logout', logout);

...

实现登录和注册需要的数据访问方法

我们新建一个models文件夹,在其中新建user.js,实例代码如下

var mysql = require('mysql');
var DB_NAME = 'nodesample';

var pool  = mysql.createPool({
    host     : '192.168.0.200',
    user     : 'root',
    password : 'abcd'
});

pool.on('connection', function(connection) {  
    connection.query('SET SESSION auto_increment_increment=1'); 
});  

function User(user){
    this.username = user.username;
    this.userpass = user.userpass;
};
module.exports = User;

pool.getConnection(function(err, connection) {

    var useDbSql = "USE " + DB_NAME;
    connection.query(useDbSql, function (err) {
         if (err) {
            console.log("USE Error: " + err.message);
            return;
         }
         console.log('USE succeed');
    });

    //保存数据
    User.prototype.save = function save(callback) {
        var user = {
            username: this.username,
            userpass: this.userpass
        };

        var insertUser_Sql = "INSERT INTO userinfo(id,username,userpass) VALUES(0,?,?)";

        connection.query(insertUser_Sql, [user.username, user.userpass], function (err,result) {
            if (err) {
                console.log("insertUser_Sql Error: " + err.message);
                return;
            }

            connection.release();

            console.log("invoked[save]");
            callback(err,result);                     
        });       
    };

    //根据用户名得到用户数量
    User.getUserNumByName = function getUserNumByName(username, callback) {

        var getUserNumByName_Sql = "SELECT COUNT(1) AS num FROM userinfo WHERE username = ?";

        connection.query(getUserNumByName_Sql, [username], function (err, result) {
            if (err) {
                console.log("getUserNumByName Error: " + err.message);
                return;
            }

            connection.release();

            console.log("invoked[getUserNumByName]");
            callback(err,result);                     
        });        
    };

    //根据用户名得到用户信息
    User.getUserByUserName = function getUserNumByName(username, callback) {

        var getUserByUserName_Sql = "SELECT * FROM userinfo WHERE username = ?";

        connection.query(getUserByUserName_Sql, [username], function (err, result) {
            if (err) {
                console.log("getUserByUserName Error: " + err.message);
                return;
            }

            connection.release();

            console.log("invoked[getUserByUserName]");
            callback(err,result);                     
        });        
    };
 
});

有这三个方法,基本登录注册就够了^_^!

注册

1.先来布局一下HTML和CSS,加上前端验证及一些提示信息显示(reg.ejs)

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">       
    <title><%= title %></title>
  
    <link rel="stylesheet" type="text/css" href="/stylesheets/bootstrap.min.css" />
    <link rel="stylesheet" type="text/css" href="/stylesheets/signin.css" />
  </head>

  <body>

    <div id="container" class="container">
       <% if (locals.success) { %> 
          <div id="alt_sucess" class="alert alert-success"> 
            <%- success %> 
          </div> 
       <% } %> 

      <% if (locals.error) { %> 
        <div id="alt_warning" class="alert alert-warning"> 
          <%= error %> 
        </div> 
      <% } %> 

      <form class="form-signin" role="form" method="post">
        <h2 class="form-signin-heading">注册</h2>

        <input id="txtUserName" name="txtUserName" type="text" class="form-control" placeholder="用户名" required autofocus />
        <input id="txtUserPwd" name="txtUserPwd" type="password" class="form-control" placeholder="密码" required/>
        <input id="txtUserRePwd"  name="txtUserRePwd" type="password" class="form-control" placeholder="重复密码" required/>   

        <button id="btnSub" class="btn btn-lg btn-primary" type="submit">注  册</button>
        <a class="btn btn-link" href="/login" role="button">登  录</a>
      </form>  
      
    </div> 
  </body>
</html>

<script src="/javascripts/jquery-1.11.1.min.js" type="text/javascript"></script>

<script type="text/javascript">
     String.prototype.format = function (args) {
            var result = this;
            if (arguments.length > 0) {
                if (arguments.length == 1 && typeof (args) == "object") {
                    for (var key in args) {
                        if (args[key] != undefined) {
                            var reg = new RegExp("({" + key + "})", "g");
                            result = result.replace(reg, args[key]);
                        }
                    }
                }
                else {
                    for (var i = 0; i < arguments.length; i++) {
                        if (arguments[i] != undefined) {
                            var reg = new RegExp("({)" + i + "(})", "g");
                            result = result.replace(reg, arguments[i]);
                        }
                    }
                }
            }
            return result;
    }

    $(function(){
        $('#btnSub').on('click',function(){
            var 
            $txtUserName = $('#txtUserName'),
            txtUserNameVal = $.trim($txtUserName.val()),            
            $txtUserPwd = $('#txtUserPwd'),
            txtUserPwdVal = $.trim($txtUserPwd.val()),
            $txtUserRePwd = $('#txtUserRePwd'),
            txtUserRePwdVal = $.trim($txtUserRePwd.val()),
            errorTip = '<div id="errorTip" class="alert alert-warning">{0}</div> ';

            $("#errorTip,#alt_sucess,#alt_warning").remove();
            
            if(txtUserNameVal.length == 0)
            {
                $("#container").prepend(errorTip.format('用户名不能为空'));                
                $txtUserName.focus();
                return false;
            }

            if(txtUserPwdVal.length == 0)
            {                
                $("#container").prepend(errorTip.format('密码不能为空'));
                $txtUserPwd.focus();
                return false;
            }

            if(txtUserRePwdVal.length == 0)
            {
                $("#container").prepend(errorTip.format('重复密码不能为空'));                
                $txtUserRePwd.focus();
                return false;
            }

            if(txtUserPwdVal != txtUserRePwdVal)
            {                 
                 $("#container").prepend(errorTip.format('两次密码不一致'));      
                 $txtUserPwd.focus();
                 return false;
            }

            return true;
        })
    });

</script>

2.实现注册功能(reg.js)

var express = require('express'),
    router = express.Router(),
    User = require('../models/user.js'),
    crypto = require('crypto'),
    TITLE_REG = '注册';

router.get('/', function(req, res) {
  res.render('reg',{title:TITLE_REG});
});

router.post('/', function(req, res) {
  var userName = req.body['txtUserName'],
      userPwd = req.body['txtUserPwd'],
      userRePwd = req.body['txtUserRePwd'],      
      md5 = crypto.createHash('md5');
 
      userPwd = md5.update(userPwd).digest('hex');

  var newUser = new User({
      username: userName,
      userpass: userPwd
  });

  //检查用户名是否已经存在
  User.getUserNumByName(newUser.username, function (err, results) {        
             
      if (results != null && results[0]['num'] > 0) {
          err = '用户名已存在';
      }

      if (err) {
          res.locals.error = err;
          res.render('reg', { title: TITLE_REG });
          return;
      }

      newUser.save(function (err,result) {
          if (err) {
              res.locals.error = err;
              res.render('reg', { title: TITLE_REG }); 
              return;            
          }        

          if(result.insertId > 0)
          {
              res.locals.success = '注册成功,请点击   <a class="btn btn-link" href="/login" role="button"> 登录 </a>' ;
          }
          else
          {
              res.locals.error = err;
          }
         
          res.render('reg', { title: TITLE_REG });
          });    
    });          
});

module.exports = router;

3.运行查看效果(命令行中cd到项目根目录,运行: node app)

运行程序后,在浏览器中输入:  http://localhost:8000/reg   ,运行后如下图

前端提示如下图:

注册成功后提示与检查数据库中插入数据!

到这里,注册功能完成(比如判断用户名是否已存在等情况显示就不列举了,自已写出来运行再看!)

登录

1.先来布局一下HTML和CSS,加上前端验证及一些提示信息显示(login.ejs)

login.ejs

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">       
    <title><%= title %></title>
  
  <link rel="stylesheet" type="text/css" href="/stylesheets/bootstrap.min.css" />
    <link rel="stylesheet" type="text/css" href="/stylesheets/signin.css" />
  </head>

  <body>

    <div id="container" class="container">
       <% if (locals.success) { %> 
          <div id="alt_sucess" class="alert alert-success"> 
            <%- success %> 
          </div> 
       <% } %> 

      <% if (locals.error) { %> 
        <div id="alt_warning" class="alert alert-warning"> 
          <%= error %> 
        </div> 
      <% } %> 

      <form class="form-signin" role="form" method="post">
        <h2 class="form-signin-heading">登录</h2>
        <input id="txtUserName" name="txtUserName" type="text" class="form-control" placeholder="用户名" required autofocus />
            <input id="txtUserPwd" name="txtUserPwd" type="password" class="form-control" placeholder="密码" required/> 
        <label class="checkbox">
          <input name="chbRem" id="chbRem" type="checkbox" value="remember-me"> 记住密码
        </label>              
        <button id="btnSub" class="btn btn-lg btn-primary" type="submit">登  录</button>
        <a class="btn btn-link" href="/reg" role="button">注  册</a>

      </form>
            
    </div> 
  </body>
</html>

<script src="/javascripts/jquery-1.11.1.min.js" type="text/javascript"></script>

<script type="text/javascript">
     String.prototype.format = function (args) {
            var result = this;
            if (arguments.length > 0) {
                if (arguments.length == 1 && typeof (args) == "object") {
                    for (var key in args) {
                        if (args[key] != undefined) {
                            var reg = new RegExp("({" + key + "})", "g");
                            result = result.replace(reg, args[key]);
                        }
                    }
                }
                else {
                    for (var i = 0; i < arguments.length; i++) {
                        if (arguments[i] != undefined) {
                            var reg = new RegExp("({)" + i + "(})", "g");
                            result = result.replace(reg, arguments[i]);
                        }
                    }
                }
            }
            return result;
    }

    $(function(){
        $('#btnSub').on('click',function(){           
            var 
            $txtUserName = $('#txtUserName'),
            txtUserNameVal = $.trim($txtUserName.val()),            
            $txtUserPwd = $('#txtUserPwd'),
            txtUserPwdVal = $.trim($txtUserPwd.val()),
            errorTip = '<div id="errorTip" class="alert alert-warning">{0}</div> ';  

            $("#errorTip,#alt_warning").remove();
            
            if(txtUserNameVal.length == 0)
            {
                $("#container").prepend(errorTip.format('用户名不能为空'));                
                $txtUserName.focus();
                return false;
            }

            if(txtUserPwdVal.length == 0)
            {                
                $("#container").prepend(errorTip.format('密码不能为空'));
                $txtUserPwd.focus();
                return false;
            }
            
            return true;                
        })
    });

</script>

2.再来完成后端代码(包括保存session和cookies记录密码)

login.js

var express = require('express'),
    router = express.Router(),
    User = require('../models/user.js'),
    crypto = require('crypto'),
    TITLE_LOGIN = '登录';

router.get('/', function(req, res) {
    res.render('login',{title:TITLE_LOGIN});
});

router.post('/', function(req, res) {
    var userName = req.body['txtUserName'],
        userPwd = req.body['txtUserPwd'],
        isRem = req.body['chbRem'],
        md5 = crypto.createHash('md5');
       
    User.getUserByUserName(userName, function (err, results) {                            
        
        if(results == '')
        {
            res.locals.error = '用户不存在';
             res.render('login',{title:TITLE_LOGIN});
             return;
        }

         userPwd = md5.update(userPwd).digest('hex');
         if(results[0].UserName != userName || results[0].UserPass != userPwd)
         {
             res.locals.error = '用户名或密码有误';
             res.render('login',{title:TITLE_LOGIN});
             console.log(1);
             return;
         }
         else
         {
             if(isRem)
             {
                res.cookie('islogin', userName, { maxAge: 60000 });                 
             }

             res.locals.username = userName;
             req.session.username = res.locals.username;  
             console.log(req.session.username);                        
             res.redirect('/');
             return;
         }     
    });              
});

module.exports = router;

3.运行查看效果

运行程序后,在浏览器中输入:  http://localhost:8000/login   ,运行后如下图

提示效果如下:

登录成功后,会跳转到首页,下面我们就着手把首页完成!

首页

首页主要为了测试登录注册的功能是否可可用,虽然首页基本没什么功能,但是我还是把它头部放到了header.ejs文件中!

1.头部HTML和CSS

header.ejs

<div class="navbar navbar-default navbar-static-top" role="navigation">
  <div class="container">
    <div class="navbar-header">         
      <a class="navbar-brand" href="/">Porschev - Nodejs + Express + Ejs + MySQL + Bootstrap 示例</a>
    </div>
    <div class="navbar-collapse collapse">
      <ul class="nav navbar-nav navbar-right">

        <% if (locals.username) { %> 
          <li><a href="#">        
                <%= username %>          
          </a></li>
          <li><a href="/logout">安全退出</a></li> 
        <% } %>           
      </ul>
    </div>              
  </div>
</div>

2.index.ejs

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">           
      <title><%= title %></title>
    <link rel="stylesheet" type="text/css" href="/stylesheets/bootstrap.min.css" />
    <link rel="stylesheet" type="text/css" href="/stylesheets/navbar-static-top.css" />   
  </head>
  <body>
      <% include header %> 
  </body>
</html>

3.index.js实现(主要是cookies,session登录状态判断)

var express = require('express'),
    router = express.Router();

router.get('/', function(req, res) {
  if(req.cookies.islogin)
  { 
         console.log('cookies:' + req.cookies.islogin);
       req.session.username = req.cookies.islogin;
  }  

  if(req.session.username)
  {    
          console.log('session:' + req.session.username);
        res.locals.username = req.session.username;      
  }
  else
  {
        res.redirect('/login');
        return;    
  }

  res.render('index',{title:'主页'});
});

module.exports = router;

4.运行,登录后,查看效果

登录,不勾选自动登录,运行http://localhost:8000 会自动跳到登录页

输入正确的用户名和密码登录成功后,页面显示如下(右上角的部分显示了用户名)

关闭浏览器,再次输入http://localhost:8000 ,跳转到登录页,需要重新登录!

再次登录,勾选自动登录

进行首页如上图;

关闭浏览器,再次输入http://localhost:8000,不会跳转到登录页,而是直接登录了!(cookies起了作用)

关闭浏览器,过一分钟后,再输入http://localhost:8000 ,跳转到登录页 (cookies失效)

安全退出

安全退出主要就是清除session(logout.js)

var express = require('express'),
     router = express.Router();

router.get('/', function(req, res) {
  req.session.destroy();
  res.redirect('/login');
});

module.exports = router;

实现效果:在不是自动登录的情况下,登录后点击安全退出,不关闭浏览器,通过url再访问首页,无法直接进入,会跳转到登录页!

 写在之后

这一篇主要是对前面所学的知识的运用,把零散的知识能真正变成能帮助你实现功能的技能!

示例并没有过多去优化代码,有很多可优化的部分,在学习的过程中去思考提升,比如:

1.怎么把代码写的更高效和优美

2.如果登录验证的部分都像index.js里那么写,那页多了怎么办?

3.像header.ejs一样的提取页面公共部分怎么才能做得更好

...

提示:

1.上面示例中我提到了“自动登录”,而我写的是“记录密码”,大家就当自动登录来用吧^_^! 

2.关于session和cookies的实现登录和自动登录部分,示例主要为了体现运用,太懒没有去按照实际规格去完成,有过web开发经验的应该都知道怎么去做以及该存储什么信息,实在不清楚的留言或邮件给我吧!