{"id":2379,"date":"2020-02-01T18:37:11","date_gmt":"2020-02-01T10:37:11","guid":{"rendered":"http:\/\/www.yuguoxy.com\/geekhome\/?p=2379"},"modified":"2021-06-25T20:18:06","modified_gmt":"2021-06-25T12:18:06","slug":"koa2-%e4%bb%8e%e5%85%a5%e9%97%a8%e5%88%b0%e8%bf%9b%e9%98%b6%e4%b8%89-%e4%b8%ad%e9%97%b4%e4%bb%b6","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=2379","title":{"rendered":"koa2 \u4ece\u5165\u95e8\u5230\u8fdb\u9636(\u4e09)-\u4e2d\u95f4\u4ef6"},"content":{"rendered":"

\u4e4b\u524d\u7684\u6587\u7ae0\u6211\u4eec\u4ecb\u7ecd\u4e86\u4e00\u4e0b koa \u8def\u7531\uff0cget \u4f20\u503c\uff0c\u52a8\u6001\u8def\u7531\uff0c\u672c\u8282\u6211\u4eec\u770b\u4e00\u4e0b koa \u4e2d\u95f4\u4ef6 \u4ee5\u53ca koa \u4e2d\u95f4\u4ef6\u7684\u6d0b\u8471\u56fe\u6267\u884c\u6d41\u7a0b\u3002<\/p>\n

\n
\n
\n

\u4e00\u3001\u4ec0\u4e48\u662f Koa \u7684\u4e2d\u95f4\u4ef6<\/strong><\/p>\n

\n
\n
\n

\u901a\u4fd7\u7684\u8bb2<\/strong>\uff1a\u4e2d\u95f4\u4ef6\u5c31\u662f\u5339\u914d\u8def\u7531\u4e4b\u524d\u6216\u8005\u5339\u914d\u8def\u7531\u5b8c\u6210\u505a\u7684\u4e00\u7cfb\u5217\u7684\u64cd\u4f5c\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u628a\u5b83\u53eb\u505a\u4e2d\u95f4\u4ef6\u3002<\/p>\n

\n
\n
\n

\u5728express\u4e2d\u95f4\u4ef6(Middleware)\u662f\u4e00\u4e2a\u51fd\u6570<\/strong>\uff0c\u5b83\u53ef\u4ee5\u8bbf\u95ee\u8bf7\u6c42\u5bf9\u8c61(request object (req)), \u54cd\u5e94\u5bf9\u8c61(response object (res)), \u548c web \u5e94\u7528\u4e2d\u5904\u7406\u8bf7\u6c42-\u54cd\u5e94\u5faa\u73af\u6d41\u7a0b\u4e2d\u7684\u4e2d\u95f4\u4ef6\uff0c\u4e00\u822c\u88ab\u547d\u540d\u4e3a next \u7684\u53d8\u91cf\u3002\u5728 Koa \u4e2d\u4e2d\u95f4\u4ef6\u548c express \u6709\u70b9\u7c7b\u4f3c\u3002<\/p>\n<\/div>\n<\/div>\n<\/div>\n

\n
\n
\n

\u4e2d\u95f4\u4ef6\u7684\u529f\u80fd\u5305\u62ec:<\/strong><\/p>\n

\u6267\u884c\u4efb\u4f55\u4ee3\u7801\u3002<\/p>\n

\u4fee\u6539\u8bf7\u6c42\u548c\u54cd\u5e94\u5bf9\u8c61\u3002<\/p>\n

\u7ec8\u7ed3\u8bf7\u6c42-\u54cd\u5e94\u5faa\u73af\u3002<\/p>\n

\u8c03\u7528\u5806\u6808\u4e2d\u7684\u4e0b\u4e00\u4e2a\u4e2d\u95f4\u4ef6\u3002<\/p>\n<\/div>\n<\/div>\n<\/div>\n

\n
\n
\n

\u5982\u679c\u6211\u7684 get\u3001post \u56de\u8c03\u51fd\u6570\u4e2d\uff0c\u6ca1\u6709 next \u53c2\u6570\uff0c\u90a3\u4e48\u5c31\u5339\u914d\u4e0a\u7b2c\u4e00\u4e2a\u8def\u7531\uff0c\u5c31\u4e0d\u4f1a\u5f80\u4e0b\u5339 \u914d\u4e86\u3002\u5982\u679c\u60f3\u5f80\u4e0b\u5339\u914d\u7684\u8bdd\uff0c\u90a3\u4e48\u9700\u8981\u5199\u00a0next()<\/strong><\/p>\n

\n
\n
\n

\u4e8c\u3001Koa \u5e94\u7528\u53ef\u4f7f\u7528\u5982\u4e0b\u51e0\u79cd\u4e2d\u95f4\u4ef6:<\/strong><\/p>\n

\u3000\u3000<\/strong>\u5e94\u7528\u7ea7\u4e2d\u95f4\u4ef6<\/p>\n

\u8def\u7531\u7ea7\u4e2d\u95f4\u4ef6<\/p>\n

\u9519\u8bef\u5904\u7406\u4e2d\u95f4\u4ef6<\/p>\n

\u7b2c\u4e09\u65b9\u4e2d\u95f4\u4ef6<\/p>\n

 <\/p>\n

\u6211\u4eec\u5148\u6765\u770b\u4e00\u4e0b\u5e94\u7528\u7ea7\u4e2d\u95f4\u4ef6\uff0c\u6211\u4eec\u8fd8\u662f\u6309\u7167\u4e4b\u524d\u7684\u9879\u76ee\u5c06 app.js \u6539\u4e3a\u5982\u4e0b\uff1a<\/p>\n

[java]
\n\/\/\u5f15\u5165 koa\u6a21\u5757
\nvar Koa = require(‘koa’);
\nvar Router = require(‘koa-router’);<\/p>\n

\/\/\u5b9e\u4f8b\u5316
\nvar app = new Koa();
\nvar router = new Router();<\/p>\n

\/\/\u5339\u914d\u4efb\u4f55\u8def\u7531\uff0c\u5982\u679c\u4e0d\u5199next\uff0c\u8fd9\u4e2a\u8def\u7531\u88ab\u5339\u914d\u5230\u4e86\u5c31\u4e0d\u4f1a\u7ee7\u7eed\u5411\u4e0b\u5339\u914d
\napp.use(async (ctx, next) => {
\n console.log("\u6211\u662f\u4e00\u4e2a\u4e2d\u95f4\u4ef6");
\n \/\/ \u5f53\u524d\u8def\u7531\u5339\u914d\u5b8c\u6210\u4ee5\u540e\u7ee7\u7eed\u5411\u4e0b\u5339\u914d
\n await next();
\n});<\/p>\n

\/\/\u914d\u7f6e\u8def\u7531
\nrouter.get(‘\/’, async (ctx) => {
\n ctx.body = "\u9996\u9875";
\n});
\nrouter.get(‘\/news’, async (ctx) => {
\n ctx.body = "\u65b0\u95fb\u5217\u9875\u9762";
\n});<\/p>\n

\/\/\u542f\u52a8\u8def\u7531
\napp.use(router.routes());
\napp.use(router.allowedMethods());<\/p>\n

app.listen(3000);
\n[\/java]<\/p>\n

\u6211\u4eec\u5728\u5339\u914d\u8def\u7531\u4e4b\u524d\u5199\u4e86\u4e00\u4e2a app.use(async ()=>{}) \u7684\u4e2d\u95f4\u4ef6\uff0c\u8be5\u4e2d\u95f4\u4ef6\u5982\u679c\u4e0d\u50cf router.get \u90a3\u6837\u5199\u4e00\u4e2a\u53c2\u6570 “\/” \u6216 “\/news”\uff0c\u90a3\u4e48\u5b83\u5c06\u5339\u914d\u4efb\u4f55\u4e00\u4e2a\u8def\u7531\uff0c\u4e14\u6700\u5148\u5339\u914d\uff0c\u5982\u679c\u6211\u4eec\u5728\u5176\u4e2d\u5199 next() \u7684\u8bdd\uff0c\u5219\u4f1a\u7ec8\u6b62\u5728\u6b64\uff0c\u4e0d\u518d\u5411\u4e0b\u966a\u966a\u8def\u7531\uff0c\u8fd0\u884c\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n

 <\/p>\n

\u6211\u4eec\u5728\u7f16\u8f91\u5668\u7684\u63a7\u5236\u53f0\u770b\u4e00\u4e0b\u8f93\u51fa\u65e5\u5fd7\uff1a<\/p>\n

 <\/p>\n

 <\/p>\n

\u63a5\u4e0b\u6765\u6211\u4eec\u770b\u4e00\u4e0b\u8def\u7531\u4e2d\u95f4\u4ef6\uff1a<\/p>\n

[java]
\n\/\/\u5f15\u5165 koa\u6a21\u5757
\nvar Koa = require(‘koa’);
\nvar Router = require(‘koa-router’);<\/p>\n

\/\/\u5b9e\u4f8b\u5316
\nvar app = new Koa();
\nvar router = new Router();<\/p>\n

\/\/\u914d\u7f6e\u8def\u7531
\nrouter.get(‘\/’, async (ctx, next) => {
\n console.log("\u63a7\u5236\u53f0\u6253\u5370");
\n \/\/ \u5f53\u524d\u8def\u7531\u5339\u914d\u5b8c\u6210\u4ee5\u540e\u7ee7\u7eed\u5411\u4e0b\u5339\u914d
\n await next();
\n});
\nrouter.get(‘\/’, async (ctx) => {
\n ctx.body = "\u9996\u9875";
\n});
\nrouter.get(‘\/news’, async (ctx) => {
\n ctx.body = "\u65b0\u95fb\u5217\u9875\u9762";
\n});<\/p>\n

\/\/\u542f\u52a8\u8def\u7531
\napp.use(router.routes());
\napp.use(router.allowedMethods());<\/p>\n

app.listen(3000);<\/p>\n

[\/java]<\/p>\n

\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u4e2d\u6211\u4eec\u5b9a\u4e49\u4e86\u4e24\u4e2a router.get(‘\/’,\u00a0 ) \u7684\u8def\u7531\uff0c\u7b2c\u4e00\u4e2a\u6211\u4eec\u5728\u63a7\u5236\u53f0\u8f93\u51fa\u4e00\u53e5\u8bdd\uff0c\u7b2c\u4e8c\u4e2a\u6211\u4eec\u60f3\u9875\u9762\u8f93\u51fa\u5185\u5bb9\u3002\u5982\u679c\u5728\u7b2c\u4e00\u4e2a\u91cc\u9762\u6211\u4eec\u4e0d\u5199 next() \u65b9\u6cd5\u7684\u8bdd\uff0c\u5219\u4e0d\u4f1a\u8fdb\u5165\u7b2c\u4e8c\u4e2a\u91cc\u9762\uff0c\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n

 <\/p>\n

\u63a7\u5236\u53f0\u6253\u5370\u7ed3\u679c<\/p>\n

 <\/p>\n

 <\/p>\n

\u63a5\u4e0b\u6765\u6211\u4eec\u770b\u4e00\u4e0b\u9519\u8bef\u5904\u7406\u4e2d\u95f4\u4ef6\uff1a<\/p>\n

[java]
\n\/\/\u5f15\u5165 koa\u6a21\u5757
\nvar Koa = require(‘koa’);
\nvar Router = require(‘koa-router’);<\/p>\n

\/\/\u5b9e\u4f8b\u5316
\nvar app = new Koa();
\nvar router = new Router();<\/p>\n

\/\/\u5339\u914d\u4efb\u4f55\u8def\u7531\uff0c\u5982\u679c\u4e0d\u5199next\uff0c\u8fd9\u4e2a\u8def\u7531\u88ab\u5339\u914d\u5230\u4e86\u5c31\u4e0d\u4f1a\u7ee7\u7eed\u5411\u4e0b\u5339\u914d
\napp.use(async (ctx,next)=>{
\n await next();
\n \/\/\u5982\u679c\u9875\u9762\u627e\u4e0d\u5230
\n if(ctx.status==404){
\n ctx.status = 404;
\n ctx.body="404 \u9875\u9762"
\n }
\n});<\/p>\n

\/\/\u914d\u7f6e\u8def\u7531
\nrouter.get(‘\/’, async (ctx) => {
\n ctx.body = "\u9996\u9875";
\n});
\nrouter.get(‘\/news’, async (ctx) => {
\n ctx.body = "\u65b0\u95fb\u5217\u9875\u9762";
\n});<\/p>\n

\/\/\u542f\u52a8\u8def\u7531
\napp.use(router.routes());
\napp.use(router.allowedMethods());<\/p>\n

app.listen(3000);
\n[\/java]<\/p>\n

\u6211\u4eec\u8fd8\u6309\u4e4b\u524d\u7684\u5e94\u7528\u4e2d\u95f4\u4ef6\u90a3\u6837\u5199\uff0c\u7136\u540e\u5728\u91cc\u9762\u505a\u4e86\u4e00\u4e2a if \u8bed\u53e5\u5224\u65ad\uff0c\u5f53\u9875\u9762\u54cd\u5e94\u65f6\uff0c\u4f1a\u7ed9\u540e\u7aef\u8fd4\u56de\u4e00\u4e2a status \u7801\uff0c\u8fd9\u4e2a\u5c31\u4e0d\u5728\u5355\u72ec\u8bf4\u4e86\uff0c\u5982\u679c\u8fd9\u4e2a status \u62a5 404\uff0c\u6211\u4eec\u77e5\u9053\u8868\u793a\u8be5\u9875\u9762\u4e0d\u5b58\u5728\uff0c\u90a3\u4e48\u6211\u4eec\u5c31\u53ef\u4ee5\u62e6\u622a next() \u65b9\u6cd5\uff0c\u8f93\u51fa\u7ed9\u524d\u7aef\u4e00\u4e2a 404 \u9875\u9762\uff0c\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n

 <\/p>\n

\u6211\u4eec\u5339\u914d\u4e86\u4e00\u4e2a “\/news” \u8def\u7531\uff0c\u53ef\u4ee5\u6b63\u5e38\u663e\u793a\u5185\u5bb9\uff0c\u5982\u679c\u6211\u4eec\u4e0d\u5c0f\u5fc3\u5c11\u5199\u4e00\u4e2a “s”\uff0c\u5199\u6210\u4e86 “new”\uff0c\u7ed3\u679c\u5982\u4e0b\uff1a<\/p>\n

 <\/p>\n

\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u4e2d\u6211\u4eec\u662f\u5c06 if \u5224\u65ad\u8bed\u53e5\u653e\u5728\u4e86 next() \u65b9\u6cd5\u4e4b\u540e\uff0c\u90a3\u80fd\u4e0d\u80fd\u653e\u5728 next() \u4e4b\u524d\u5462\uff1f\u8fd9\u4e2a\u95ee\u9898\u6211\u4eec\u5728\u4e0b\u9762\u7684 koa \u4e2d\u95f4\u4ef6\u6d41\u7a0b\u63a7\u5236\u4e2d\u518d\u8be6\u7ec6\u8bf4\u660e\u3002<\/p>\n

 <\/p>\n

\u7b2c\u4e09\u65b9\u4e2d\u95f4\u4ef6\u5728\u4e4b\u540e\u7684\u6587\u7ae0\u4e2d\u6211\u4eec\u7528\u5230\u4e86\u7b2c\u4e09\u65b9\u6a21\u5757\u65f6\u518d\u8bf4\u3002<\/p>\n

\u63a5\u4e0b\u6765\u6211\u4e48\u770b\u4e00\u4e0b koa \u4e2d\u7684\u4e2d\u95f4\u4ef6\u6d41\u7a0b\u63a7\u5236\u3002<\/p>\n

koa\u88ab\u8ba4\u4e3a\u662f\u7b2c\u4e8c\u4ee3node web framework\uff0c\u5b83\u6700\u5927\u7684\u7279\u70b9\u5c31\u662f\u72ec\u7279\u7684\u4e2d\u95f4\u4ef6\u6d41\u7a0b\u63a7\u5236\uff0c\u662f\u4e00\u4e2a\u5178\u578b\u7684\u6d0b\u8471\u6a21\u578b\u3002<\/p>\n

 <\/p>\n

 <\/p>\n

 <\/p>\n

\u4e0a\u9762\u7684\u4e24\u5f20\u56fe\u53ef\u4ee5\u5f88\u76f4\u89c2\u7684\u8bf4\u660e koa \u4e2d\u7684\u4e2d\u95f4\u4ef6\u6d41\u7a0b\u63a7\u5236\u3002\u6211\u4eec\u63a5\u4e0b\u6765\u7528\u4ee3\u7801\u6f14\u793a\u4e00\u4e0b\uff1a<\/p>\n

[java]
\n\/\/\u5f15\u5165 koa\u6a21\u5757
\nvar Koa = require(‘koa’);
\nvar Router = require(‘koa-router’);<\/p>\n

\/\/\u5b9e\u4f8b\u5316
\nvar app = new Koa();
\nvar router = new Router();<\/p>\n

app.use(async (ctx, next) => {
\n console.log(‘1\u3001\u8fd9\u662f\u7b2c\u4e00\u4e2a\u4e2d\u95f4\u4ef601’);
\n await next();
\n console.log(‘5\u3001\u5339\u914d\u8def\u7531\u5b8c\u6210\u4ee5\u540e\u53c8\u4f1a\u8fd4\u56de\u6765\u6267\u884c\u4e2d\u95f4\u4ef6’);
\n});<\/p>\n

app.use(async (ctx, next) => {
\n console.log(‘2\u3001\u8fd9\u662f\u7b2c\u4e8c\u4e2a\u4e2d\u95f4\u4ef602’);
\n await next();
\n console.log(‘4\u3001\u5339\u914d\u8def\u7531\u5b8c\u6210\u4ee5\u540e\u53c8\u4f1a\u8fd4\u56de\u6765\u6267\u884c\u4e2d\u95f4\u4ef6’);
\n});<\/p>\n

router.get(‘\/’, async (ctx) => {
\n console.log(‘3\u3001\u5339\u914d\u5230\u4e86news\u8fd9\u4e2a\u8def\u7531’);
\n ctx.body = "\u9996\u9875";
\n});<\/p>\n

\/\/\u542f\u52a8\u8def\u7531
\napp.use(router.routes());
\napp.use(router.allowedMethods());<\/p>\n

app.listen(3000);
\n[\/java]<\/p>\n

\u6211\u4eec\u5728\u4e0a\u9762\u7684\u4ee3\u7801\u5f15\u7528\u4e86\u4e24\u4e2a\u5e94\u7528\u7ea7\u7684\u4e2d\u95f4\u4ef6\uff0c\u5206\u522b\u5728 next() \u524d\u540e\u8f93\u51fa\u65e5\u5fd7\uff0c\u5f53\u6211\u4eec\u8bbf\u95ee localhost:3000\/ \u65f6\uff0c\u6211\u4eec\u770b\u4e00\u4e0b\u63a7\u5236\u53f0\u7684\u8f93\u51fa\u7ed3\u679c\uff1a<\/p>\n

 <\/p>\n

\u4ece\u8f93\u51fa\u6253\u5370\u7ed3\u679c\u987a\u5e8f\u6211\u4eec\u53ef\u4ee5\u770b\u51fa\u4e2d\u95f4\u4ef6\u4f1a\u5148\u9010\u7ea7\u5904\u7406 request\u00a0 \u8bf7\u6c42\uff0c\u7136\u540e\u518d\u8fd4\u56de\u6765\u9010\u7ea7\u5904\u7406 response \u8bf7\u6c42\uff0c\u8fd9\u5c31\u662f\u6211\u4eec\u4e3a\u4ec0\u4e48\u8981\u5c06 \u9519\u8bef\u5904\u7406\u4e2d\u95f4\u4ef6 \u4e2d\u7684 if \u5224\u65ad\u8bed\u53e5\u653e\u5728 next() \u65b9\u6cd5\u4e4b\u540e\uff0c\u8fd9\u6837\u5c31\u662f\u5728\u8def\u7531\u8fdb\u5165 “\/news” \u540e\u8fd4\u56de status = 404 \u7684\u7ed3\u679c\u540e\u518d\u8fdb\u884c\u5904\u7406\uff0c\u5982\u679c\u653e\u5728\u4e86 next() \u65b9\u6cd5\u4e4b\u524d\uff0c\u5219\u4f1a\u76f4\u63a5\u5224\u65ad if \u8bed\u53e5\uff0c\u4e0d\u4f1a\u518d\u5411\u4e0b\u5339\u914d “\/news” \u8def\u7531\u4e86\u3002\u6bd4\u5982\u6211\u4eec\u7684\u7528\u6237\u767b\u5f55\u7cfb\u7edf\u5c31\u53ef\u4ee5\u8fd9\u4e48\u7528\uff0c\u5f53\u7528\u6237\u8f93\u5165\u8d26\u53f7\u5bc6\u7801\u540e\u51fa\u5165\u540e\u53f0\uff0c\u540e\u53f0\u5728\u6570\u636e\u5e93\u5339\u914d\u4e4b\u540e\u518d\u8fdb\u884c\u5904\u7406\uff0c\u5904\u7406\u4e4b\u540e\u8fd4\u56de\u7ed9\u524d\u7aef\uff0c\u5c31\u662f\u8fd9\u4e48\u73a9\u7684\u3002<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\u4e4b\u524d\u7684\u6587\u7ae0\u6211\u4eec\u4ecb\u7ecd\u4e86\u4e00\u4e0b koa \u8def\u7531\uff0cget \u4f20\u503c\uff0c\u52a8\u6001\u8def\u7531\uff0c\u672c\u8282\u6211\u4eec\u770b\u4e00\u4e0b koa \u4e2d\u95f4\u4ef6 \u4ee5\u53ca koa […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[107,105],"tags":[],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2379"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2379"}],"version-history":[{"count":5,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2379\/revisions"}],"predecessor-version":[{"id":3266,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/2379\/revisions\/3266"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2379"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2379"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2379"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}