nodejs爬虫简单实现

const fs = require('fs');
const URL = require('url')
const gbk = require('gbk')
const { JSDOM } = require('jsdom')

class Getdata {
    static http(url) {
        let Url = URL.parse(url)
        let http;
        if (Url.protocol == 'http:') {
            http = require('http')
            return { "http": http, 'hostname': Url.hostname, 'path': Url.path }
        } else {
            http = require('https')
            return {
                "http": http, 'hostname': Url.hostname, 'path': Url.path
            };
        }
    }
    get(url, Filename) {
        Getdata.a += 1
        let app = Getdata.http(url);
        let https = app.http.request({
            'hostname': app.hostname,
            'path': app.path
        }, res => {
            if (res.statusCode == 200) {
                // console.log(res.statusCode)
                let arr = []
                res.on('data', data => {
                    // console.log(data);
                    arr.push(data)
                }).on('end', () => {
                    let b = Buffer.concat(arr)
                    // let html = gbk.toString('utf-8', b)
                    let dom = new JSDOM(b);
                    let doc = dom.window.document.querySelectorAll('.Left_list_cont2 img');

                    for (let i = 0; i < doc.length; i++) {
                        let a = doc[i].getAttribute('data-original')                    // console.log()
                        this.set(a, `${Filename}${i}`, 'jpg')
                    }
                })
            } else {
                console.log(Getdata.a);
                console.log(res.statusCode, res.headers);
                this.get(url, Filename)
            }
        })
        https.end()
    }

    set(url, Filename, kz = 'html') {
        Getdata.a += 1
        let app = Getdata.http(url);
        let https = app.http.request({
            'hostname': app.hostname,
            'path': app.path
        }, res => {
            if (res.statusCode == 200) {
                // console.log(res.statusCode)
                let arr = []
                res.on('data', data => {
                    // console.log(data);
                    arr.push(data)
                }).on('end', () => {
                    let b = Buffer.concat(arr)
                    fs.writeFile('img/' + Filename + '.' + kz, b, () => {
                        console.log('成功了');
                    })

                })
            } else {
                console.log(Getdata.a);
                console.log(res.statusCode, res.headers);
                this.get(url, Filename)
            }
        })
        https.end()
    }


}
Getdata.a = 0;