koa-router 404 on node.js - node.js

Question

platform
node: v-4.4.5 koa: v-2.0.0 koa-router: v-7.0.0
here is my code
///<reference path="../typings/tsd.d.ts" />
//导入koa，和koa 1.x不同，在koa2中，我们导入的是一个class，因此用大写的Koa表示:
var Koa = require('koa');
var router=require("koa-router")();
// 创建一个Koa对象表示web app本身:
var app = new Koa();
// parse request body:
//add url-route:
router.get('/hello/:name', (ctx, next) => {
var name = ctx.params.name;
ctx.response.body =`<h1>Hello, ${name}!</h1>`;
});
router.get('/', function *(ctx, next) {
ctx.response.body = '<h1>Index</h1>';
});
router.all('/login', function *() {
this.redirect('/');
this.status = 301;
});
app.use(function (ctx,next){
this.body = `Invalid URL!!!${ctx.request.method} ${ctx.request.url}`;
ctx.response.type = 'text/html';
ctx.response.body = this.body;
});
app.use(router.routes())
.use(router.allowedMethods());
// 在端口3000监听:
app.listen(3000);
console.log('app started at port 3000...');
when I Brower http://localhost:3000/,output 'Invalid URL!!!'. tell me why can't match '/' router ? thank you!

Answer 1

you can use '*' to match urls like 404 or invalid links:
router.all('*', function(ctx, next) {
//
});

Answer 2

upgrade your node version to 7.6.0. koa2 work on >=7.6.0
and code like
Koa=require('koa')
var app = new Koa();
router = require('koa-router')()
// parse request body:
//add url-route:
router.get('/hello/:name', (ctx, next) => {
var name = ctx.params.name;
ctx.response.body =`<h1>Hello, ${name}!</h1>`;
});
router.get('/', function (ctx, next) {
console.log(ctx.request);
ctx.body = '<h1>Index</h1>';
});
router.all('/login', function (ctx) {
ctx.redirect('/');
ctx.status = 301;
});
app.use(function (ctx,next){
this.body = `Invalid URL!!!${ctx.request.method} ${ctx.request.url}`;
ctx.response.type = 'text/html';
ctx.response.body = this.body;
next()
});
app.use(router.routes())
.use(router.allowedMethods());
// 在端口3000监听:
app.listen(3000);
console.log('app started at port 3000...');