Node.js实现简单的爬取的示例代码

//引入依赖//https请求const https = require('https');//简称node版的jqueryconst cheerio = require('cheerio');//解决防止出现乱码const iconv = require('iconv-lite')//http请求const request = require("request");//负责读写文件const fs = require('fs');//处理文件路径const path = require('path');

const url = 'https://unsplash.com/';

//方法对象const util = {   getsrc: function (url) {    https.get(url, res => {      const chunks = [];      res.on('data', chunk => {        // chunks里面存储着网页的html内容        chunks.push(chunk);      });      res.on('end', e => {         let ALL = [];        //编码格式        let html = iconv.decode(Buffer.concat(chunks), 'utf8');        let $ = cheerio.load(html, { decodeEntities: false });         //标签遍历        $("figure img").each(function (idex, elent) {          let $elent = $(elent);          let $srcset = $elent.attr("srcset");          if ($srcset != undefined) {            let src = ($srcset.split(',').pop()).split('?')[0];            ALL.push({              src: src            })          }        });        //遍历数组 每个后面加.jpg        ALL.forEach(item => {          util.downloadimg(item.src, path.basename(item.src) + ".jpg", function () {            console.log(path.basename(item.src) + ".jpg");          });        })      });       res.on('error', e => {        console.log('Error: ' + e.message);      });    });  },   //运行主函数  main: function () {    console.log("------start--------");    util.getsrc(url);  },  //下载图片函数  downloadimg: function (src, srcname, callback) {     //http请求    request.head(src, function (err, res, body) {      if (err) {        console.log('err:' + err);        return false;      }      console.log('res: ' + res);      //保存数据，这里是防止未来得及记录数据又开始读取数据而导致数据丢失      request(src).pipe(fs.createWriteStream('./img/' + srcname)).on('close', callback);    });  }} //主函数util.main();