一站式网上办事大厅

// 选课系统示例代码

const express = require('express');

const jwt = require('jsonwebtoken');

const app = express();

app.use(express.json());

// JWT密钥

const secretKey = 'secretkey';

// 模拟数据库

const courses = [

{ id: 1, name: '生物化学', available: true },

{ id: 2, name: '医学统计学', available: false }

];

// 验证Token中间件

function authenticateToken(req, res, next) {

const authHeader = req.headers['authorization'];

const token = authHeader && authHeader.split(' ')[1];

if (token == null) return res.sendStatus(401);

jwt.verify(token, secretKey, (err, user) => {

if (err) return res.sendStatus(403);

req.user = user;

next();

});

}

// 获取课程列表

app.get('/courses', authenticateToken, (req, res) => {

res.json(courses);

});

// 学生选课

app.post('/selectCourse/:id', authenticateToken, (req, res) => {

const courseId = parseInt(req.params.id);

const course = courses.find(course => course.id === courseId);

if (!course) return res.status(404).send('课程不存在');

if (!course.available) return res.status(400).send('课程已满或不可用');

res.send(`成功选修课程：${course.name}`);

});

app.listen(3000, () => console.log('选课系统已启动'));