Node.js 之HTTP 小爬虫 （详细版）

var http = require('http');

var cheerio = require('cheerio');

var url = 'http://www.imooc.com/learn/348';

function filterChapters(html) {

var $ = cheerio.load(html);

var chapters = $('.chapter');

var courseData = [];

chapters.each(function(item) {

var chapter = $(this);

var chapterTitle = chapter.find('strong').text();

var videos = chapter.find('.video').children('li');

var chapterData = {

chapterTitle: chapterTitle,

video: []

};

videos.each(function(item) {

var video = $(this).find('.J-media-item');

var videoTitle = video.text();

var id = video.attr('href').split('video/')[1];

chapterData.video.push({

title: videoTitle,

id: id

});

});

//console.log(chapterData.video);

courseData.push(chapterData);

});

return courseData;

}

function printCourseInfo(courseData) {

courseData.forEach(function(item) {

var chapterTitle = item.chapterTitle;

console.log(chapterTitle + '\n');

item.video.forEach(function(video) {

console.log('【' + video.id + '】' + video.title + '\n');

});

});

}

http.get(url, function(res) {

var html = '';

res.on('data', function(data) {

html += data;

});

res.on('end', function() {

var courseData = filterChapters(html);

//console.log(courseData.video);

printCourseInfo(courseData);

}).on('error', function() {

console.log('获取课程数据出错');

});

});