express初步认识

// 1. 引入
const express = require('express');

// 2. 创建web服务器
const app = express();

// 根据路由(路径)处理get和post请求
app.get('/', (req, res)=>{
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.write('<h2>Hello, World!</h2>');
    res.end();
});

app.get('/like', (req, res)=>{
    res.writeHead(200, {'Content-Type': 'text/html;charset=utf-8;'});
    res.write('<h2>撩课学院!</h2>');
    res.end();
});

app.get('/it', (req, res)=>{
    res.writeHead(200, {'Content-Type': 'text/html;charset=utf-8;'});
    res.write('<h2>like it, it like!</h2>');
    res.end();
});


// 3. 开启监听
app.listen(3000, ()=>{
   console.log('服务器已经启动!');
});

express中间键

// 1. 引入
const express = require('express');
const fs = require('fs');
const path = require('path');

// 2. 创建web服务器
const app = express();

// 4. 写日志
app.use((req, res, next)=>{
    const log = `
      ----------------------------------------
      1) 请求的方式: ${req.method}, 

      2) 请求的路径: ${req.url}, 

      3) 请求的时间: ${new Date()}, 

      ----------------------------------------
    `;
    //  写入文件
    fs.appendFile(path.join(__dirname, 'req.log'), log, (err)=>{
        if(err) throw err;
        next();
    });
});

// 加入很多很多中间件
app.use((req, res, next)=>{
    console.log('1111111');
    next();
});

app.use((req, res, next)=>{
    console.log('2222222');
    next();
});

app.use((req, res, next)=>{
    console.log('333333');
    next();
});


app.get('/', (req, res, next)=>{
    res.writeHead(200, {'Content-Type': 'text/html;charset=utf-8'});
    res.write('<h2>Hello, World!</h2>');
    next();
});

app.get('/', (req, res)=>{
    res.write('<h2>您好,撩课学院!</h2>');
    res.end();
});



// 3. 开启监听
app.listen(3000, ()=>{
    console.log('服务器已经启动!');
});

服务器搭建网站的初步

const express = require('express');
const path = require('path');
const app = express();

// 中间件访问静态资源
app.use(express.static(path.join(__dirname, 'public')));

app.listen(3001, ()=>{
    console.log('服务器已经启动');
});

express实现动态的渲染ejs

const express = require('express');
const path = require('path');
const app = express();

// 注册模板引擎
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

app.get('/', (req, res)=>{
    const dataJson = {
        "lists":[
            {"title": "撩课学院1周年庆倒计时", "count": 675593, "up": 1},
            {"title": "女演员全美善自杀", "count": 634434, "up": 1},
            {"title": "哈登骑电动车被抓", "count": 623323, "up": 0},
            {"title": "吃酸辣粉被罚款", "count": 546767, "up": 0},
            {"title": "蔚来汽车庄莉离职", "count": 536237, "up": 1},
            {"title": "父母抓阄陪女儿", "count": 525193, "up": 0},
            {"title": "宋仲基爸爸短信", "count": 475593, "up": 0},
            {"title": "宋仲基爸爸短信", "count": 375593, "up": 1},
            {"title": "今天天气很好", "count": 275593, "up": 1}
        ],
        "source": "撩课风云榜 - itLike.com"
    };
    res.render('list', dataJson);
});

app.listen(3000, ()=>{
    console.log('服务器已经启动');
});