创建Express后端项目
1.创建项目
npm init -y
touch index.js
node index
npm install express --save
2.安装修改自动更新
npm i nodemon -g
在package.json里加入：“dev:live”: “nodemon ./src/app.ts”
{"name": "express","version": "1.0.0","main": "index.js","scripts": {"test": "echo \"Error: no test specified\" && exit 1","dev:live": "nodemon ./src/app.ts"},"keywords": [],"author": "","license": "ISC","description": "","dependencies": {"body-parser": "^1.20.3","cors": "^2.8.5","express": "^4.21.0"}
}2.安装跨域和表单中间件
npm i cors
npm i body-parser
3.编写index.js
// 导入express
const express = require('express');// 创建Web服务器
const app = express();//引入cors
const cors = require('cors');
app.use(cors());// 引入body-parser
const bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());// 监听服务器
app.listen('8089', () => {console.log('server started at 8089');
});//监听一个/user的GET请求接口，并返回响应数据：
app.get('/user', async (req, res, next) => {// res.send向客户端发送响应数据res.send({name: 'xiaoli',age: 20,gender: '男'});
});// 监听一个/user的POST请求接口，并返回响应数据：
app.post('/user', async (req, res, next) => {// res.send向客户端发送响应数据res.send('请求成功');
});