npm install express@4

//導(dǎo)入express模塊
const express = require('express');
//創(chuàng)建Web服務(wù)器
let app = express();
//啟動Web服務(wù)器
app.listen(52273, ()=>{
     console.log("服務(wù)器監(jiān)聽地址是 http://127.0.0.1:52273");
});

//引入express模塊
const express = require('express');
//創(chuàng)建服務(wù)器
const app = express();
//監(jiān)聽請求與響應(yīng)
app.use((request, response)=>{
     //創(chuàng)建數(shù)組
     let output = [];
     for (let i = 0; i < 3; i++) {
          output.push({
               count: i,
               name: 'name - ' + i
          });
     }
     //向客戶端返回數(shù)組類型的信息
     response.send(output);
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址在 http://127.0.0.1:52273');
});

//導(dǎo)入express模塊
const express = require('express');
//創(chuàng)建服務(wù)器
const app = express();
//監(jiān)聽請求和響應(yīng)
app.use((request, response)=>{
     //獲取客戶端的User-Agent
     let agent = request.header('User-Agent');
     //判斷客戶端瀏覽器的類型
     if (agent.toLowerCase().match(/chrome/)) {
          //發(fā)送響應(yīng)信息
          response.send('<h1>*_*歡迎使用谷歌瀏覽器</h1>');
     } else {
          //發(fā)送響應(yīng)信息
          response.send('<h1>^_^您使用的不是谷歌瀏覽器，
當(dāng)然這并不影響瀏覽網(wǎng)頁</h1>');
     }
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址在 http://127.0.0.1:52273');
});

app.use([path,] callback[,callback])

//導(dǎo)入express模塊
const express = require('express');
//創(chuàng)建服務(wù)器
let app = express();
//設(shè)置中間件
app.use((request, response, next)=>{
     //定義變量
     request.number = 20;
     response.number =35;
     next();
});
app.use((request, response, next)=>{
     //發(fā)送響應(yīng)信息
     response.send('<h1 style="color:green">' + request.number + ' : ' + response.number + '</h1>');
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址在 http://127.0.0.1:52273');
});

//導(dǎo)入express模塊
const express = require('express');
//創(chuàng)建服務(wù)器
let app = express();
//設(shè)置頁面路由規(guī)則
app.get('/page/:id', (request, response)=>{
     //獲取request對象
     let name = request.params.id;
     //發(fā)送響應(yīng)信息
     response.send('<h2 style="color:red">' + name + ' Page</h2>');
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址在 http://127.0.0.1:52273');
});

express.static(root[,options])

const express = require('express');
//創(chuàng)建服務(wù)器
let app = express();
//使用static中間件
app.use(express.static(__dirname + '/image'));
app.use((request, response)=>{
     //發(fā)送響應(yīng)信息
     response.writeHead(200, {'Content-Type': 'text/html'});
     response.end('<img src="/82.jpg" width="100%" />');
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器地址在 http://127.0.0.1:52273');
});

npm install cookie-parser

cookie parser([secret])

//導(dǎo)入模塊
const express = require('express');
const cookieParser = require('cookie-parser');
//創(chuàng)建服務(wù)器
let app = express();
//設(shè)置cookie parser中間件
app.use(cookieParser());
app.get('/', (request, response)=>{
     //設(shè)置cookie內(nèi)容
     response.cookie('string', 'cookie');
     response.cookie('json', {
          name: 'cookie',
          property: 'delicious'
     })
     response.send(request.cookies)
     app.get('/get', (request, response)=>{
          //發(fā)送響應(yīng)信息
          response.send(request.cookies);
     });
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器地址在 http://127.0.0.1:52273');
});

npm install body-parser

const fs = require('fs');
const express = require('express');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
//創(chuàng)建服務(wù)器
let app = express();
//設(shè)置中間件
app.use(cookieParser());
//extended選項為false，表示使用querystring庫轉(zhuǎn)換URL-encoded數(shù)據(jù)
app.use(bodyParser.urlencoded({ extended: false }));
//設(shè)置路由配置
app.get('/', (request, response)=>{
     if (request.cookies.auth) {
          response.send('<h1 style="color:red;text-align: center">登錄成功</h1>');
     } else {
          response.redirect('/login');
     }
});
app.get('/login', (request, response)=>{
     //讀取登錄頁面
     fs.readFile('login.html', (error, data)=>{
          response.send(data.toString());
     });
});
app.post('/login', (request, response)=>{
     //記錄登錄用戶
     let login = request.body.login;
     //記錄登錄密碼
     let pass = request.body.pass;
     //判斷登錄是否成功
     if (login == 'mingrisoft' && pass == '123456') {
          //登錄成功，使用cookie記錄登錄成功標(biāo)識
          response.cookie('auth', true);
          response.redirect('/');                             //跳轉(zhuǎn)頁面
     } else {
          //登錄失敗
          response.redirect('/login');
     }
});
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址是 http://127.0.0.1:52273');
});

<!DOCTYPE html>
<html>
<head>
     <meta charset="utf-8">
     <title>登錄頁面</title>
</head>
<body>
     <form method="post">
          <fieldset style="width: 250px;margin: 0 auto;padding:20px">
               <legend style="color:#ff5722">管理員登錄</legend>
               <table>
                    <tr>
                         <td>
                              <label for="user">賬   號:</label>
                         </td>
                         <td>
                              <input type="text" name="login" id="user"/>
                         </td>
                    </tr>
                    <tr height="40">
                          <td>
                               <label for="pass">密   碼：</label>
                          </td>
                          <td>
                               <input type="pass" name="pass" id="pass"/>
                          </td>
                     </tr>
                     <tr>
                          <td colspan="2" align="center">
                               <input type="submit" style="background: #41d7ea;width: 85px;height: 25px;
                                     border: 1px solid #e0ac5e;outline: none;border-radius: 5px;"/>
                          </td>
                     </tr>
               </table>
          </fieldset>
     </form>
</body>
</html>

//創(chuàng)建虛擬數(shù)據(jù)庫
module.exports = (function(){
    let DummyDB = {};
    let storage = [];
    let count = 1;
    //查詢數(shù)據(jù)庫
    DummyDB.get = (id)=>{
        if(id) {
            //將id轉(zhuǎn)換為數(shù)字類型
            id = (typeof id == 'string') ? Number(id) : id;
            //遍歷存儲數(shù)據(jù)，并判斷是否找到相應(yīng)的id
            for(let i in storage) {
                if(storage[i].id == id){
                    return storage[i];
                }
            } 
        } else {
            return storage;
        }
    }
    //添加數(shù)據(jù)
    DummyDB.insert = (data)=>{
        data.id = count++;
        storage.push(data);
        return data;
    }
    //刪除數(shù)據(jù)
    DummyDB.remove = (id)=>{
        id = (typeof id == 'string') ? Number(id) : id;
        for(let i in storage) {
            if(storage[i].id == id) {
                //刪除數(shù)據(jù)
                storage.splice(i, 1);
                return true;
            }
        }
        return false;
    }
    return DummyDB;
})();

<!DOCTYPE html>
<html>
<head>
     <meta charset="utf-8">
     <title>add User</title>
</head>
<body>
     <form method="post">
          <fieldset style="width: 250px;margin: 0 auto;padding:20px">
               <legend style="color:#ff5722">登錄賬戶</legend>
               <table>
                     <tr>
                          <td><label>用戶名：</label></td>
                          <td><input type="text" name="name"/></td>
                     </tr>
                     <tr height="40">
                          <td><label>密   碼：</label></td>
                          <td><input type="password" name="pass"/></td>
                     </tr>
                     <tr>
                          <td colspan="2" align="center">
                               <input type="submit" style="background: #41d7ea;width: 85px;height: 25px;
                                          border: 1px solid #e0ac5e;outline: none;border-radius: 5px;"/>
                          </td>
                     </tr>
               </table>
          </fieldset>
     </form>
</body>
</html>

const fs = require('fs');
const express = require('express');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
const DummyDB = require('./db.js');
//創(chuàng)建服務(wù)器
let app = express();
//設(shè)置中間件
app.use(cookieParser());
//extended選項為false，表示使用querystring庫轉(zhuǎn)換URL-encoded數(shù)據(jù)
app.use(bodyParser.urlencoded({ extended: false }));
//查詢所有用戶信息
app.get('/user', (request, response)=>{
    response.send(DummyDB.get());
});
//查詢指定id的用戶信息
app.get('/user/:id', (request, response)=>{
    response.send(DummyDB.get(request.params.id));
});
//添加用戶
app.get('/addUser', (request, response)=>{
    fs.readFile('addUser.html', (error, data)=>{
        response.send(data.toString());
    });
});
app.post('/addUser', (request, response)=>{
    let name = request.body.name;
    let pass = request.body.pass;
    if(name && pass) {
        response.send(DummyDB.insert({
            name: name,
            pass: pass
        }));
    } else {
        throw new Error('error');
    }
});
//刪除指定id的用戶
app.delete('/user/:id', (request, response)=>{
    if(DummyDB.remove(request.params.id)) {
        response.send('刪除成功');
    }else{
        response.send('刪除失敗');
    }
})
//啟動服務(wù)器
app.listen(52273, ()=>{
     console.log('服務(wù)器監(jiān)聽地址是 http://127.0.0.1:52273');
});

npm install -g express-generator

cd ../
express my_project

express –e project

express login

cd login
npm install

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var session = require('express-session');
var FileStore = require('session-file-store')(session);
var bodyParser = require('body-parser');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
//導(dǎo)入自定義模塊
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
//創(chuàng)建服務(wù)器對象
var app = express();
var identityKey = 'skey';
var users = require('./routes/user').items;
var findUser = function(name, password){
  return users.find((item)=>{
    return item.name === name && item.password === password;
  })
}

//對服務(wù)器進(jìn)行設(shè)置
app.set('views', path.join(__dirname, 'views'));
var ejs = require('ejs');
//將ejs模板映射至html文件
app.engine(".html", ejs.__express);
app.set("view engine", "html");

//設(shè)置中間件
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(session({
  name: identityKey,
  secret: 'mingrisoft', //用來對session_id相關(guān)的cookie進(jìn)行簽名
  store: new FileStore(), //本地存儲session
  saveUninitialized: false, //是否自動保存未初始化的會話
  resave: false, //是否每次都重新保存會話
  cookie: {
    maxAge: 1000 * 1000 //有效期，單位是毫秒
  }
}));

//GET請求，設(shè)置用戶登錄狀態(tài)
app.get("/", function(req, res, next){
  var sess = req.session;
  var loginUser = sess.loginUser;//記錄登錄用戶
  var isLogined = !loginUser; //將登錄用戶變量轉(zhuǎn)換為對應(yīng)的布爾值
  res.render("index", {
    isLogined: isLogined,
    name: loginUser 
  });
});

//Post請求，判斷用戶是否能夠登錄成功
app.post("/login", function(req, res, next){
  var sess = req.session;
  var user = findUser(req.body.name, req.body.password);
  if(user) {
    req.session.regenerate(function(err){
      if(err){
        return res.json({ret_code: 2, ret_msg: '登錄失敗'});
      }
      req.session.loginUser = user.name;
      res.json({ret_code: 0, ret_msg: '登錄成功'});
    })
  } else {
    res.json({ret_code: 1, ret_msg: '賬號或密碼錯誤'});
  }
});

//GET請求，退出登錄時，清空session
app.get("/logout", function(req, res, next){
  req.session.destroy(function(err){
    if(err){
      res.json({ret_code:2, ret_msg: '退出登錄s失敗'});
      return;
    }
    res.clearCookie(identityKey);
    res.redirect("/");
  });
});



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

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

module.exports = {
     items: [
          {name: 'mingrisoft', password: '123456'}
     ]
};

<!DOCTYPE html>
<html>
<head>
     <title>會話管理</title>
</head>
<body>
     <h2 style="text-align: center">會話管理</h2>
     <p id="loged">
          當(dāng)前登錄用戶：<span style="color:red"><%= name %></span>，<a href="/logout" rel="external nofollow"  id="logout">退出登錄</a>
     </p>
     <fieldset style="width: 300px;text-align: center;margin: 10px auto;border:1px solid #4caf50" id="unlog">
          <legend style="text-align: left">登錄</legend>
          <form method="POST" action="/login">
               <label style="display: block;margin-top: 20px">
                     用戶名：<input type="text" id="name" name="name" value=""/>
               </label>
               <label style="display: block;margin: 20px auto">
                     密&nbsp;&nbsp;碼：<input type="password" id="password" name="password" value=""/>
               </label>
               <div style="text-align: center;margin-bottom: 10px">
                     <input type="submit" value="登錄" id="login" style="background: #cddc39;border:1px solid #ff9800"/>
               </div>
          </form>
     </fieldset>
     <script type="text/javascript" src="/jquery-3.1.0.min.js"></script>
     <script>
          if (isLogined) {
               $("#loged").css("display", "block")
               $("#unlog").css("display", "none")
          }
          else {
               $("#unlog").css("display", "block")
               $("#loged").css("display", "none")
          }
     </script>
     <script type="text/javascript">
          $('#login').click(function (evt) {
               evt.preventDefault();
               $.ajax({
                     url: '/login',
                     type: 'POST',
                     data: {
                          name: $('#name').val(),
                          password: $('#password').val()
                     },
                     success: function (data) {
                          if (data.ret_code === 0) {
                               location.reload();
                          }
                     }
               });
          });
     </script>
</body>
</html>

<!doctype html>
<html>
<head>
     <meta charset="utf-8">
     <title>出錯了</title>
</head>
<body>
<script>
     document.getElementById("mess").innerHTML=message;
     document.getElementById("err").innerHTML=error;
     document.getElementById("errt").innerHTML=error.stack;
</script>
</body>
</html>

/**
 * Get port from environment and store in Express.
 */
var port = normalizePort(process.env.PORT || '52273');
app.set('port', port);

npm install koa

const Koa = require('koa');
const app = new Koa();

const Koa = require('koa');
const app = new Koa();
app.use(async ctx => {
     ctx.body = 'Hello World';
});
app.listen(3000);

const Koa = require("koa")
const app = new Koa()
app.use((ctx, next) => {
     console.log("first")
     next()                           //設(shè)置中間件
     console.log("third")
     ctx.body = '在koa中使用中間件';
})
app.use((ctx, next) => {
     //同步操作
     console.log("second")
})
app.listen(3000)