尝试使用Socket.io时Next.JS自定义服务器重新启动，地址已在使用中:3000

netstat -ano | findstr :3000
taskkill /PID <进程ID> /F

lsof -i :3000
kill -9 <进程ID>

"scripts": {
  "dev": "node server.js",
  "start": "NODE_ENV=production node server.js"
}

const express = require('express');
const next = require('next');
const http = require('http');
const socketIo = require('socket.io');

const dev = process.env.NODE_ENV !== 'production';
const app = next({ dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  const server = express();
  const httpServer = http.createServer(server);
  const io = socketIo(httpServer);

  io.on('connection', (socket) => {
    console.log('New client connected');
    socket.on('disconnect', () => {
      console.log('Client disconnected');
    });
  });

  server.all('*', (req, res) => {
    return handle(req, res);
  });

  httpServer.listen(3001, (err) => {
    if (err) throw err;
    console.log('> Ready on http://localhost:3001');
  });
});

PORT=3001

const port = process.env.PORT || 3000;
httpServer.listen(port, (err) => {
  if (err) throw err;
  console.log(`> Ready on http://localhost:${port}`);
});