问net.createConnection ECONNREFUSED

EN

const net = require('net');
const client = net.createConnection({ port: 8124}, () => {
  // 'connect' listener.
  console.log('connected to server!');
  client.write('world!\r\n');
});
client.on('error', function(e) {
    console.log(e);
    console.log(e.message);
});
client.on('data', (data) => {
  console.log(data.toString());
  client.end();
});
client.on('end', () => {
  console.log('disconnected from server');
});

Error: connect ECONNREFUSED 127.0.0.1:8124
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1146:16) {
  errno: -4078,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 8124
}
connect ECONNREFUSED 127.0.0.1:8124