node.js 实现一个简单的 web 服务器还是比较简单的，以前利用 express 框架实现过『nodeJS搭一个简单的(代理)web服务器』。代码量很少，可是使用时需要安装依赖，多处使用难免有点不方便。于是便有了完全使用原生 api 来重写的想法，也当作一次 node.js 复习。
1、静态 web 服务器
'use strict'
const http = require('http')
const url = require('url')
const fs = require('fs')
const path = require('path')
const cp = require('child_process')
const port = 8080
const hostname = 'localhost'
// 创建 http 服务
let httpServer = http.createServer(processStatic)
// 设置监听端口
httpServer.listen(port, hostname, () => {
console.log(`app is running at port:${port}`)
console.log(`url: http://${hostname}:${port}`)
cp.exec(`explorer http://${hostname}:${port}`, () => {})
})
// 处理静态资源
function processStatic(req, res) {
const mime = {
css: 'text/css',
gif: 'image/gif',
html: 'text/html',
ico: 'image/x-icon',
jpeg: 'image/jpeg',
jpg: 'image/jpeg',
js: 'text/javascript',
json: 'application/json',
pdf: 'application/pdf',
png: 'image/png',
svg: 'image/svg+xml',
woff: 'application/x-font-woff',
woff2: 'application/x-font-woff',
swf: 'application/x-shockwave-flash',
tiff: 'image/tiff',
txt: 'text/plain',
wav: 'audio/x-wav',
wma: 'audio/x-ms-wma',
wmv: 'video/x-ms-wmv',
xml: 'text/xml'
}
const requestUrl = req.url
let pathName = url.parse(requestUrl).pathname
// 中文乱码处理
pathName = decodeURI(pathName)
let ext = path.extname(pathName)
// 特殊 url 处理
if (!pathName.endsWith('/') && ext === '' && !requestUrl.includes('?')) {
pathName += '/'
const redirect = `http://${req.headers.host}${pathName}`
redirectUrl(redirect, res)
}
// 解释 url 对应的资源文件路径
let filePath = path.resolve(__dirname + pathName)
// 设置 mime
ext = ext ? ext.slice(1) : 'unknown'
const contentType = mime[ext] || 'text/plain'
// 处理资源文件
fs.stat(filePath, (err, stats) => {
if (err) {
res.writeHead(404, { 'content-type': 'text/html;charset=utf-8' })
res.end('404 Not Found
')
return
}
// 处理文件
if (stats.isFile()) {
readFile(filePath, contentType, res)
}
// 处理目录
if (stats.isDirectory()) {
let html = "- "
// 遍历文件目录，以超链接返回，方便用户选择
fs.readdir(filePath, (err, files) => {
if (err) {
res.writeHead(500, { 'content-type': contentType })
res.end('
- ${file} ` } html += '
500 Server Error
') return } else { for (let file of files) { if (file === 'index.html') { const redirect = `http://${req.headers.host}${pathName}index.html` redirectUrl(redirect, res) } html += `500 Server Error
') }) stream.pipe(res) }2、代理功能
// 代理列表
const proxyTable = {
'/api': {
target: 'http://127.0.0.1:8090/api',
changeOrigin: true
}
}
// 处理代理列表
function processProxy(req, res) {
const requestUrl = req.url
const proxy = Object.keys(proxyTable)
let not_found = true
for (let index = 0; index < proxy.length; index++) {
const k = proxy[index]
const i = requestUrl.indexOf(k)
if (i >= 0) {
not_found = false
const element = proxyTable[k]
const newUrl = element.target + requestUrl.slice(i + k.length)
if (requestUrl !== newUrl) {
const u = url.parse(newUrl, true)
const options = {
hostname : u.hostname,
port : u.port || 80,
path : u.path,
method : req.method,
headers : req.headers,
timeout : 6000
}
if(element.changeOrigin){
options.headers['host'] = u.hostname + ':' + ( u.port || 80)
}
const request = http
.request(options, response => {
// cookie 处理
if(element.changeOrigin && response.headers['set-cookie']){
response.headers['set-cookie'] = getHeaderOverride(response.headers['set-cookie'])
}
res.writeHead(response.statusCode, response.headers)
response.pipe(res)
})
.on('error', err => {
res.statusCode = 503
res.end()
})
req.pipe(request)
}
break
}
}
return not_found
}
function getHeaderOverride(value){
if (Array.isArray(value)) {
for (var i = 0; i < value.length; i++ ) {
value[i] = replaceDomain(value[i])
}
} else {
value = replaceDomain(value)
}
return value
}
function replaceDomain(value) {
return value.replace(/domain=[a-z.]*;/,'domain=.localhost;').replace(/secure/, '')
}
3、完整版
服务器接收到 http 请求，首先处理代理列表 proxyTable，然后再处理静态资源。虽然这里面只有二个步骤，但如果按照先后顺序编码，这种方式显然不够灵活，不利于以后功能的扩展。koa 框架的中间件就是一个很好的解决方案。完整代码如下：
'use strict'
const http = require('http')
const url = require('url')
const fs = require('fs')
const path = require('path')
const cp = require('child_process')
// 处理静态资源
function processStatic(req, res) {
const mime = {
css: 'text/css',
gif: 'image/gif',
html: 'text/html',
ico: 'image/x-icon',
jpeg: 'image/jpeg',
jpg: 'image/jpeg',
js: 'text/javascript',
json: 'application/json',
pdf: 'application/pdf',
png: 'image/png',
svg: 'image/svg+xml',
woff: 'application/x-font-woff',
woff2: 'application/x-font-woff',
swf: 'application/x-shockwave-flash',
tiff: 'image/tiff',
txt: 'text/plain',
wav: 'audio/x-wav',
wma: 'audio/x-ms-wma',
wmv: 'video/x-ms-wmv',
xml: 'text/xml'
}
const requestUrl = req.url
let pathName = url.parse(requestUrl).pathname
// 中文乱码处理
pathName = decodeURI(pathName)
let ext = path.extname(pathName)
// 特殊 url 处理
if (!pathName.endsWith('/') && ext === '' && !requestUrl.includes('?')) {
pathName += '/'
const redirect = `http://${req.headers.host}${pathName}`
redirectUrl(redirect, res)
}
// 解释 url 对应的资源文件路径
let filePath = path.resolve(__dirname + pathName)
// 设置 mime
ext = ext ? ext.slice(1) : 'unknown'
const contentType = mime[ext] || 'text/plain'
// 处理资源文件
fs.stat(filePath, (err, stats) => {
if (err) {
res.writeHead(404, { 'content-type': 'text/html;charset=utf-8' })
res.end('404 Not Found
')
return
} // 处理文件
if (stats.isFile()) {
readFile(filePath, contentType, res)
} // 处理目录
if (stats.isDirectory()) {
let html = "- "
// 遍历文件目录，以超链接返回，方便用户选择
fs.readdir(filePath, (err, files) => {
if (err) {
res.writeHead(500, { 'content-type': contentType })
res.end('
- ${file} ` } html += '
500 Server Error
') return } else { for (let file of files) { if (file === 'index.html') { const redirect = `http://${req.headers.host}${pathName}index.html` redirectUrl(redirect, res) } html += `500 Server Error
') }) stream.pipe(res) } // 处理代理列表 function processProxy(req, res) { const requestUrl = req.url const proxy = Object.keys(proxyTable) let not_found = true for (let index = 0; index < proxy.length; index++) { const k = proxy[index] const i = requestUrl.indexOf(k) if (i >= 0) { not_found = false const element = proxyTable[k] const newUrl = element.target + requestUrl.slice(i + k.length) if (requestUrl !== newUrl) { const u = url.parse(newUrl, true) const options = { hostname : u.hostname, port : u.port || 80, path : u.path, method : req.method, headers : req.headers, timeout : 6000 }; if(element.changeOrigin){ options.headers['host'] = u.hostname + ':' + ( u.port || 80) } const request = http.request(options, response => { // cookie 处理 if(element.changeOrigin && response.headers['set-cookie']){ response.headers['set-cookie'] = getHeaderOverride(response.headers['set-cookie']) } res.writeHead(response.statusCode, response.headers) response.pipe(res) }) .on('error', err => { res.statusCode = 503 res.end() }) req.pipe(request) } break } } return not_found } function getHeaderOverride(value){ if (Array.isArray(value)) { for (var i = 0; i < value.length; i++ ) { value[i] = replaceDomain(value[i]) } } else { value = replaceDomain(value) } return value} function replaceDomain(value) { return value.replace(/domain=[a-z.]*;/,'domain=.localhost;').replace(/secure/, '') } function compose (middleware) { if (!Array.isArray(middleware)) throw new TypeError('Middleware stack must be an array!') for (const fn of middleware) { if (typeof fn !== 'function') throw new TypeError('Middleware must be composed of functions!') } return function (context, next) { // 记录上一次执行中间件的位置 let index = -1 return dispatch(0) function dispatch (i) { // 理论上 i 会大于 index，因为每次执行一次都会把 i递增， // 如果相等或者小于，则说明next()执行了多次 if (i <= index) return Promise.reject(new Error('next() called multiple times')) index = i let fn = middleware[i] if (i === middleware.length) fn = next if (!fn) return Promise.resolve() try { return Promise.resolve(fn(context, function next () { return dispatch(i + 1) })) } catch (err) { return Promise.reject(err) } } } } function Router(){ this.middleware = [] } Router.prototype.use = function (fn){ if (typeof fn !== 'function') throw new TypeError('middleware must be a function!') this.middleware.push(fn) return this} Router.prototype.callback= function() { const fn = compose(this.middleware) const handleRequest = (req, res) => { const ctx = {req, res} return this.handleRequest(ctx, fn) } return handleRequest } Router.prototype.handleRequest= function(ctx, fn) { fn(ctx) } // 代理列表 const proxyTable = { '/api': { target: 'http://127.0.0.1:8090/api', changeOrigin: true } } const port = 8080 const hostname = 'localhost' const appRouter = new Router() // 使用中间件 appRouter.use(async(ctx,next)=>{ if(processProxy(ctx.req, ctx.res)){ next() } }).use(async(ctx)=>{ processStatic(ctx.req, ctx.res) }) // 创建 http 服务 let httpServer = http.createServer(appRouter.callback()) // 设置监听端口 httpServer.listen(port, hostname, () => { console.log(`app is running at port:${port}`) console.log(`url: http://${hostname}:${port}`) cp.exec(`explorer http://${hostname}:${port}`, () => {}) })以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。