Express框架基本使用

用法和Flask 很相似

文档&＃xff1a;
英文&＃xff1a;http://expressjs.com/
中文&＃xff1a;https://www.expressjs.com.cn/

初始化项目

# 初始化
$ npm init# 安装
cnpm install express nodemon -S


项目结构

server.js
package.json
node_modules/


简单示例

server.js

const express &＃61; require("express");const app &＃61; express();app.get("/", (request, response) &＃61;> {response.send("hello world!");
})const port &＃61; process.env.PORT || 5000;app.listen(port, () &＃61;> {console.log(&＃96;Server runing on http://127.0.0.1:${port}&＃96;);
})


运行

$ node server.js


http://127.0.0.1:5000/

配置热重载

配置package.json

{"name": "demo","version": "1.0.0","description": "","main": "server.js","scripts": {"start": "node server.js","dev": "nodemon server.js"},"author": "","license": "ISC","dependencies": {"express": "^4.17.1","nodemon": "^2.0.2"}
}


热重载模式启动

$ npm run dev


数据交互

接收参数&＃xff0c;返回json


/*** body 默认是undefined&＃xff0c;需要添加解析中间件*/
// for parsing application/json
app.use(express.json())
// for parsing application/x-www-form-urlencoded
app.use(express.urlencoded({ extended: true })) app.post("/json/:key", (request, response) &＃61;>{const data &＃61; {body: request.body,params: request.params,query: request.query}response.json({ msg: &＃39;success&＃39;, code: 0, data: data})
} )

请求测试

POST http://127.0.0.1:5000/json/value?name&＃61;Tom&age&＃61;23
Content-Type: application/json; charset&＃61;utf-8{"school": "Tsinghua"
}反回数据{"msg": "success","code": 0,"data": {"body": {"school": "Tsinghua"},"params": {"key": "value"},"query": {"name": "Tom","age": "23"}}
}