将数据从express.js发送到react js

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

dataRouter.get('/data', (req, res) => {
  // 处理数据请求的逻辑
  const data = {
    message: 'Hello from Express.js!'
  };
  res.json(data);
});

module.exports = dataRouter;

const express = require('express');
const app = express();
const dataRouter = require('./dataRouter');

app.use('/api', dataRouter);

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

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      data: null
    };
  }

  componentDidMount() {
    fetch('/api/data')
      .then(response => response.json())
      .then(data => {
        this.setState({ data });
      })
      .catch(error => {
        console.error('Error:', error);
      });
  }

  render() {
    const { data } = this.state;

    return (
      <div>
        {data ? <p>{data.message}</p> : <p>Loading...</p>}
      </div>
    );
  }
}

export default MyComponent;