js如何取服务器时间

fetch('/api/get-server-time')
  .then(response => response.json())
  .then(data => {
    const serverTime = new Date(data.serverTime);
    console.log('服务器时间:', serverTime);
  })
  .catch(error => {
    console.error('获取服务器时间失败:', error);
  });

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

const socket = new WebSocket('ws://example.com/socket');

socket.onopen = () => {
  socket.send('get-server-time');
};

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

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

wss.on('connection', (ws) => {
  ws.on('message', (message) => {
    if (message === 'get-server-time') {
      const serverTime = new Date();
      ws.send(serverTime.getTime());
    }
  });
});

fetch('/api')
  .then(response => {
    const serverTime = new Date(response.headers.get('Date'));
    console.log('服务器时间:', serverTime);
  })
  .catch(error => {
    console.error('获取服务器时间失败:', error);
  });