express4里要单独安装cookie-parser和express-session

express4里要单独安装cookie-parser和express-session:

1 2	`npm install express-session --save` `npm install cookie-parser --save`

有关代码替换成

var cookieParser = require('cookie-parser')

var session = require('express-session')

app.use(cookieParser())

app.use(session({

secret: 'imooc'

}))

参考地址：