【Node.js】http 模块

1. http 模块

import http from 'http'
// 创建本地服务器接收数据
const server = http.createServer((req, res) => {console.log(req.url)res.writeHead(200, { 'Content-Type': 'application/json' // 'Content-Type': 'text/html;charset=utf-8'  // 将内容以 html 标签和 utf-8 的形式展示到网页上 })// write 中的内容直接展示到网页上// res.write('hello')res.end(JSON.stringify({data: "hello"}))
})
server.listen(8000,()=> {console.log("server is running")
})

1.1 解决跨域问题

接口 jsonp 解决跨域

// server.js
const http = require('http')
const url = require('url')const app = http.createServer((req, res) => {let urlObj = url.parse(req.url, true)console.log(urlObj.query.callback)switch (urlObj.pathname) {case '/api/user':res.end(`${urlObj.query.callback}(${JSON.stringify({name:'xxx',age:18})})`)breakdefault:res.end('404.')break}
})app.listen(3000, () => {console.log('localhost:3000')
})

<!-- index.html -->
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head><body><script>const oscript = document.createElement('script');oscript.src = 'http://localhost:3000/api/user?callback=test';document.body.appendChild(oscript);function test(obj) {console.log(obj)}</script></body></html>

CORS 解决跨域

// server.js
const http = require('http')
const url = require('url')const app = http.createServer((req, res) => {let urlObj = url.parse(req.url, true)// console.log(urlObj.query.callback)res.writeHead(200, {'Content-Type': 'application/json; charset=utf-8',// CORS 头'Access-Control-Allow-Origin': '*'})switch (urlObj.pathname) {case '/api/user':res.end(`${JSON.stringify({ name: 'xxx', age: 18 })}`)breakdefault:res.end('404.')break}
})app.listen(3000, () => {console.log('localhost:3000')
})

<!-- index.html -->
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head><body><script>fetch('http://localhost:3000/api/user').then(res=>res.json()).then(res=>console.log(res))</script></body></html>

1.2 作为客户端

Node.js 既可以做服务端开发，又可以做客户端开发。

get

<!-- index.html -->
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head><body><script>fetch('http://localhost:3000/api/user').then(res=>res.json()).then(res=>console.log(res))</script>
</body></html>

// get.js
const http = require('http')
const https =  require('https')
const url = require('url')const app = http.createServer((req, res) => {let urlObj = url.parse(req.url, true)// console.log(urlObj.query.callback)res.writeHead(200, {'Content-Type': 'application/json; charset=utf-8',// CORS 头'Access-Control-Allow-Origin': '*'})switch (urlObj.pathname) {case '/api/user':// 现在作为客户端 去猫眼api请求数据// 注意协议要统一：https还是httphttpget(res)breakdefault:res.end('404.')break}
})
app.listen(3000, () => {console.log('localhost:3000')
})
function httpget(response) {let data = ''https.get(`https://i.maoyan.com/api/mmdb/movie/v3/list/hot.json?ct=%E7%9F%B3%E5%AE%B6%E5%BA%84&ci=76&channelId=4`,res => {// data 是一份一份的数据收集，end 是最终收集到的所有数据res.on('data', chunk => {data += chunk})res.on('end', () => {console.log(data)response.end(data)})})
}

另一种写法：

// get.js
const http = require('http')
const https =  require('https')
const url = require('url')const app = http.createServer((req, res) => {let urlObj = url.parse(req.url, true)// console.log(urlObj.query.callback)res.writeHead(200, {'Content-Type': 'application/json; charset=utf-8',// CORS 头'Access-Control-Allow-Origin': '*'})switch (urlObj.pathname) {case '/api/user':// 现在作为客户端 去猫眼api请求数据// 注意协议要统一：https还是http// data 收集好的时候调用内部传入的 cb 函数httpget((data)=> {res.end(data)})breakdefault:res.end('404.')break}
})
app.listen(3000, () => {console.log('localhost:3000')
})
function httpget(cb) {let data = ''https.get(`https://i.maoyan.com/api/mmdb/movie/v3/list/hot.json?ct=%E7%9F%B3%E5%AE%B6%E5%BA%84&ci=76&channelId=4`,res => {// data 是一份一份的数据收集，end 是最终收集到的所有数据res.on('data', chunk => {data += chunk})res.on('end', () => {console.log(data)cb(data)})})
}

post

<!-- index.html -->
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head><body><script>fetch('http://localhost:3000/api/user').then(res=>res.json()).then(res=>console.log(res))</script></body></html>

// post.js
const http = require('http')
const https = require('https')
const url = require('url')const app = http.createServer((req, res) => {let urlObj = url.parse(req.url, true)// console.log(urlObj.query.callback)res.writeHead(200, {'Content-Type': 'application/json; charset=utf-8',// CORS 头'Access-Control-Allow-Origin': '*'})switch (urlObj.pathname) {case '/api/user':// 现在作为客户端 去小米优品 api 请求数据// 注意协议要统一：https还是httphttpPost((data) => {res.end(data)})breakdefault:res.end('404.')break}
})
app.listen(3000, () => {console.log('localhost:3000')
})
function httpPost(cb) {let data = ''const options = {hostname: 'm.xiaomiyoupin.com',port: '443', // 80 是 http 默认端口号，443 是 https 默认端口号path: '/mtop/market/search/placeHolder',methods: "POST",headers: {"Content-Type": "application/json",}}const req = https.request(options, (res) => {res.on('data', (chunk) => {data += chunk})res.on('end', () => {cb(data)})})req.write(JSON.stringify([{}, { baseParam: { ypClient: 1 } }]))req.end()
}