js ajax跨域解决方案

Access-Control-Allow-Origin: *

Access-Control-Allow-Origin: https://example.com

function handleResponse(response) {
    console.log('The responsed data is: ' + response.data);
}

var script = document.createElement('script');
script.src = 'https://example.com/api/data?callback=handleResponse';
document.body.appendChild(script);

var socket = new WebSocket('wss://example.com/socketserver');

fetch('https://example.com/api/data', {
    method: 'GET',
    credentials: 'include'
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

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

app.use((req, res, next) => {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
    next();
});

app.get('/data', (req, res) => {
    res.json({ message: 'This is data from the server.' });
});

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