如何从Express服务器上的React应用程序获取数据，以使用从API获取的数据更新元标记

const express = require('express');
const router = express.Router();

router.get('/data', (req, res) => {
  // 从数据库或其他数据源获取数据
  const data = { name: 'John', age: 25 };

  res.json(data);
});

module.exports = router;

const express = require('express');
const cors = require('cors');
const apiRouter = require('./api');

const app = express();

app.use(cors());
app.use('/api', apiRouter);

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

import React, { useState, useEffect } from 'react';

const App = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch('http://localhost:3000/api/data')
      .then(response => response.json())
      .then(data => setData(data))
      .catch(error => console.log(error));
  }, []);

  return (
    <div>
      {data && (
        <div>
          <h1>{data.name}</h1>
          <p>Age: {data.age}</p>
        </div>
      )}
    </div>
  );
};

export default App;