js怎么获取服务器时间

function getServerTime() {
    fetch('/api/get-server-time') // 假设服务器端有一个/api/get-server-time的接口
        .then(response => response.json())
        .then(data => {
            console.log('服务器时间:', new Date(data.serverTime));
        })
        .catch(error => {
            console.error('获取服务器时间失败:', error);
        });
}

getServerTime();

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

app.get('/api/get-server-time', (req, res) => {
    const serverTime = new Date().toISOString();
    res.json({ serverTime });
});

app.listen(3000, () => {
    console.log('服务器运行在 http://localhost:3000');
});

const socket = new WebSocket('ws://example.com/socket'); // 假设服务器端有一个WebSocket服务

socket.onopen = () => {
    console.log('WebSocket连接已打开');
};

socket.onmessage = (event) => {
    const serverTime = new Date(event.data);
    console.log('服务器时间:', serverTime);
};

socket.onerror = (error) => {
    console.error('WebSocket错误:', error);
};

socket.onclose = () => {
    console.log('WebSocket连接已关闭');
};

const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 8080 });

wss.on('connection', (ws) => {
    const serverTime = new Date().toISOString();
    ws.send(serverTime);
});