参考23课koa2源码解读

1、源码解源码解koa理： 常见koao间件的实前准堂目手写手写ico间koaApplicationo间件机常见o间/ const http = class listen(.args) const server = res) = this.callback(req, this.callback(req, this.callback = module.exports = / 调用，const KKB = const app = new app.use(req, res) res.writeHead(200); app.listen(3000, () 端封装request1response和/ req

2、uest.js module.exports = get return this.r / response.js module.exports = get body() return set this._body = / context.js module.exports = get url() return get body() return set get body() return set this.response.body = / / 导入这Onconst context = require(./context); const request = const response = c

3、lass listen(.args) const server = http.createServer(req, res) = / PQlet ctx = this.createContext(req, / / / PQ文, 把res和req都d载rctx之P 并且在 qsrconst ctx = Object.creat (co pctx.request = t ( t ctx.response Obje )ctx.req = ctx. ctx.res = ctxreturn qtp/ app.js ctx.body = o间_步o间件：要支casync + await的o间件，要等_步结束

4、_步o间件：要支casync + await的o间件，要等_步结束function return function() return / 执行第function dispatch( ) let fn = middl wif (!fn) return return Promise. fn(function next() (/ promise完成，再执行Q一return dispatch(i + async function console.log(fn1); await next(); console.log(end fn1);async function await delay();await

5、 console.log(end function functionawait console.log(end function function delay() return new Promise(reslove, reject) setTimeout() , = const middlewares = const finalFn = comfn1, fn2, e用在const http = context = request = response = require(./res )KKB / _始化o间件数 listen(.args) const server = http const

6、ctx = / ot t C ( sync (req, res) t(req, const fn = po ( / 函数并传入PQawait fn(ctx); use(middleware) / 将o间件r函e(middlewares) return function(ctx) / 传入PQreturn dispatch(0); function dispatch(i) let fn = if (!fn) return return if (!fn) return return fn(ctx, function next() / 将PQ文传入o间件，mid(ctx,next) return d

7、ispatch(i + 1);createContext(req, res) let ctx = Object.create(context); ctx.request = Object.create(request); ctx.response = ctx.req = ctx.request.req = ctx.res = ctx.response.res = res; return ctx;module.exports = 用function sleep() return new Promise(reslove setTimeout() = , japp.use(async ody = 1

8、; setTimeout() ctx.body += , await next(); ctx.body += 3;app.use(async (ctx, next) ctx.body += 4; await delay(); await next(); ctx.body += 5;app.use(async (ctx, next) ctx.body += e的常见koao间件的实实现loggeromodule.exports = async function(ctx, nexte的常见koao间件的实实现loggeromodule.exports = async function(ctx, n

9、ext) 操作请求 const start = new Date().getTime() console.log(start: $ctx.url); await next();const end = new Date().getTime() console.log(请求$ctx.url, 耗时(end-请将module.exports = async function(ctx, const res, req = ctx; const blackList = ;const ip = / 出现在黑单o将if (blackList.includes(ip) ctx.body = not allowe

10、d; else await function return q) / 判断是否有反/ 判断 connection / 判断端的 socket 的 req.headersx-f w d d req.connection.rem t Add req.socket.remoteAd r/ app.listen(3000, , () = 端口静态文件服koa-/ const fs = require(fs); const path = require(path);module.exports = (dirPath = ./public) return async (ctx, next) = if (c

11、tx.url.module.exports = (dirPath = ./public) return async (ctx, next) = if (ctx.url.indexOf(/public) = 0) / public_头 取文url = path.resolve( dirname, aseName = filepath = url + ctx.url.replace(/public, / console.log(ctx.url,url, filepath, fitry s = if s.isDirectory() const dir = / const ret = ; dir.fo

12、rEach(filename = 简单认不带小数点的格式，就是文件夹if (filename.indexOf(.) - $filename else / $ret.push( /d else )t console.log( 文件 const content = ctx.body = catch (e) / 报错了 文件不存ctx.body = 404, not else / 否则不是静态资源，直接Q一noawait /const ic = /const ic = 路由 routes()的返回值是一no间件，由于需要用rtd所以需要d载trctx之P，修改module.exports get r

13、eturn get return class constructor() this.stack = ;ath, methods, middlew r let route = path, methods, dd w / 现在只支cgett，其get(path,middleware this.register( thg )t(path,midd this.regist (p dd routes() let stock = this.sta return async function(ctx, let currentPath = ctx.url; let route;for (let i = 0; i = 0) / 判断path和method route = item.middleware;if (typeof route = route(ctx, next); await module.exports = const Koa = requireawait module.exports = const Koa = require(./kkb) const Router = require(./router) const app = new Koa()con