node之http模块之爬虫和event

爱学习的前端歌谣

发布于 2023-12-10 14:06:20

1850

发布于 2023-12-10 14:06:20

文章被收录于专栏：前端小歌谣

前言

我是歌谣微信公众号关注前端小歌谣一起学习前端知识今天继续给大家讲解node中爬虫的讲解

安装

 npm init -y
 npm i cheerio

案例

var http=require("http")
var url=require("url")
var https=require("https")
var cheerio=require("cheerio")
http.createServer((req,res)=>{
     var urlobj=url.parse(req.url)
     res.writeHead(200,{
        "content-Type":"application/json;charset=utf-8",
        "access-control-allow-origin":"*"
     })
     switch(urlobj.pathname){
        case "/api/aaa":
            httpget((data)=>{
                res.end(spider(data))
            })
            break
        default:
            res.end("404")
     }
}).listen(3000)


function httpget(cb){
    var data=""
    https.get(`https://i.maoyan.com/`,(res)=>{
        res.on("data",(chunk)=>{
           data+=chunk
        })
        res.on("end",()=>{
           cb(data)
        })
    })
}




function spider(data){
    let $=cheerio.load(data)
    let $movielist=$("")
     console.log($)
     let movie=[]
     $movielist.each((index,value)=>{
        movie.push($(value).find(".title").text())
     })
    return JSON.stringify(movie)
}

运行结果

前言

我是歌谣微信公众号关注前端小歌谣一起学习前端知识今天继续给大家讲解node中event的讲解

案例

const EventEmitter=require("events")
const event=new EventEmitter()
event.on("play",()=>{
    console.log("事件触发了")
})
event.emit("play")

运行结果

案例1

var http=require("http")
var url=require("url")
var https=require("https")
const EventEmitter=require("events")
var event=null
http.createServer((req,res)=>{
     var urlobj=url.parse(req.url)
     res.writeHead(200,{
        "content-Type":"application/json;charset=utf-8",
        "access-control-allow-origin":"*"
     })
     switch(urlobj.pathname){
        case "/api/aaa":
            event=new EventEmitter()
            event.on("play",(data)=>{
                res.end(data)
            })
              httpget()
            break
        default:
            res.end("404")
     }
}).listen(3000)


function httpget(){
    var data=""
    https.get(`https://i.maoyan.com/api/mmdb/movie/v3/list/hot.json`,(res)=>{
        res.on("data",(chunk)=>{
           data+=chunk
        })
        res.on("end",()=>{
        //    console.log(data)
           event.emit("play",data)
        //    response.end(data)
        })
    })
}

运行结果