获取Get方法中的用户角色

const express = require('express');
const app = express();

// 使用查询字符串参数
app.get('/api/resource', (req, res) => {
  const role = req.query.role;
  if (role) {
    res.send(`User role is: ${role}`);
  } else {
    res.status(400).send('Role is required');
  }
});

// 使用路径参数
app.get('/api/resource/:role', (req, res) => {
  const role = req.params.role;
  res.send(`User role is: ${role}`);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});

if (!req.query.role) {
  return res.status(400).send('Role is required');
}

const validRoles = ['admin', 'user'];
if (!validRoles.includes(req.query.role)) {
  return res.status(400).send('Invalid role');
}