1 //HTTP小爬虫 2 //×××××类似 $.AJAX×××××× 3  4  5 var http = require(‘http‘); //加载http模块 6  7 var cheerio = require(‘cheerio‘);//加载第三方模块 cheerio 类似JQuery 8  9 // 安装方法 npm install cheerio10 11 12 function printCourseInfo(courseData) {//打印函数 传入获取数据13     courseData.forEach(function(item) {//循环打印14         var chapterTitle = item.chapterTitle;15 16         console.log(chapterTitle + ‘\n‘);17 18         item.videos.forEach(function(video) {19             console.log(‘[‘ + video.id + ‘]‘ + video.title + ‘\n‘);20         })21     })22 }23 24 25 function fliterChapters(html) {//数据筛选函数26 27     var $ = cheerio.load(html);28 29     var chapters = $(‘.chapter‘)//获取元素30 31 32 //目标数据结构33     /*    [{34             capterTitle:‘‘,35             videos:‘‘,36             id:‘‘37         }]*/38 39     var courseData = http://www.mamicode.com/[];//存放数组40 41 42     chapters.each(function(item) {43         var chapters = $(this);44 45         var chapterTitle = chapters.find(‘strong‘).text();46 47 48         var videos = chapters.find(‘.video‘).children(‘li‘);49 50         var chapterData =http://www.mamicode.com/ {51             chapterTitle: chapterTitle,52             videos: []53         }54 55         videos.each(function(item) {56             var video = $(this).find(‘.J-media-item‘);57             var videoTitle = video.text();58             var id = video.attr(‘href‘).split(‘video/‘)[1]59 60 61             chapterData.videos.push({62                 title: videoTitle,63                 id: id64             })65         })66 67 68         courseData.push(chapterData);69     })70 71     return courseData//数据拼接完成并返回72 73 }74 75 //目标url76 var url = ‘http://www.imooc.com/learn/348‘;//慕课网77 78 79 80 //使用get方法81 http.get(url, function(res) {//get方法爬取代码82     var html = ‘‘;83 84     res.on(‘data‘, function(data) {//获取数据事件85         html += data;86     })87 88     res.on(‘end‘, function() {//获取结束事件89         var courseData =http://www.mamicode.com/ fliterChapters(html);90 91         printCourseInfo(courseData);92     })93 94 }).on(‘error‘, function() {95     console.log(‘获取错误！‘);//报错96 })