摘要：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...
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}${pathName}` redirectUrl(redirect, res) } // 解释 url 对应的资源文件路径 let filePath = path.resolve(__dirname + pathName) // 设置 mime ext = ext ? ext.slice(1) : unknown const contentType = mime[ext] || text/plain // 处理资源文件 fs.stat(filePath, (err, stats) => { if (err) { res.writeHead(404, { content-type: text/html;charset=utf-8 }) res.end(<h1>404 Not Found</h1>) return } // 处理文件 if (stats.isFile()) { readFile(filePath, contentType, res) } // 处理目录 if (stats.isDirectory()) { let html = "<head><meta charset = utf-8/></head><body><ul>" // 遍历文件目录，以超链接返回，方便用户选择 fs.readdir(filePath, (err, files) => { if (err) { res.writeHead(500, { content-type: contentType }) res.end(<h1>500 Server Error</h1>) return } else { for (let file of files) { if (file === index.html) { const redirect = `http://${req.headers.host}${pathName}index.html` redirectUrl(redirect, res) } html += `<li><a href=${file}>${file}</a></li>` } html += </ul></body> res.writeHead(200, { content-type: text/html }) res.end(html) } }) } }) } // 重定向处理 function redirectUrl(url, res) { url = encodeURI(url) res.writeHead(302, { location: url }) res.end() } // 文件读取 function readFile(filePath, contentType, res) { res.writeHead(200, { content-type: contentType }) const stream = fs.createReadStream(filePath) stream.on(error, function() { res.writeHead(500, { content-type: contentType }) res.end(<h1>500 Server Error</h1>) }) 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}${pathName}` redirectUrl(redirect, res) } // 解释 url 对应的资源文件路径 let filePath = path.resolve(__dirname + pathName) // 设置 mime ext = ext ? ext.slice(1) : unknown const contentType = mime[ext] || text/plain // 处理资源文件 fs.stat(filePath, (err, stats) => { if (err) { res.writeHead(404, { content-type: text/html;charset=utf-8 }) res.end(<h1>404 Not Found</h1>) return } // 处理文件 if (stats.isFile()) { readFile(filePath, contentType, res) } // 处理目录 if (stats.isDirectory()) { let html = "<head><meta charset = utf-8/></head><body><ul>" // 遍历文件目录，以超链接返回，方便用户选择 fs.readdir(filePath, (err, files) => { if (err) { res.writeHead(500, { content-type: contentType }) res.end(<h1>500 Server Error</h1>) return } else { for (let file of files) { if (file === index.html) { const redirect = `http://${req.headers.host}${pathName}index.html` redirectUrl(redirect, res) } html += `<li><a href=${file}>${file}</a></li>` } html += </ul></body> res.writeHead(200, { content-type: text/html }) res.end(html) } }) } }) } // 重定向处理 function redirectUrl(url, res) { url = encodeURI(url) res.writeHead(302, { location: url }) res.end() } // 文件读取 function readFile(filePath, contentType, res) { res.writeHead(200, { content-type: contentType }) const stream = fs.createReadStream(filePath) stream.on(error, function() { res.writeHead(500, { content-type: contentType }) res.end(<h1>500 Server Error</h1>) }) 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}`, () => {}) })版权声明：除特别声明外，本站所有文章皆是来自互联网，转载请以超链接形式注明出处！
