请用nodejs实现物联网应用程序通信协议使用COAP服务端监听客户端的请求每隔一毫秒发送当前时间的字符串。当服务器有新的相应数据时客户端将其打印到控制台上

以下是一个基本的COAP服务器示例，它将在每隔一毫秒发送当前时间的字符串。

const coap = require('coap');
const server = coap.createServer();

server.on('request', (req, res) => {
  console.log(`Received ${req.method} request for ${req.url}`);
  let currentTime = new Date().toISOString();
  res.end(currentTime);
});

server.listen(() => {
  console.log('COAP server listening');
});

setInterval(() => {
  let currentTime = new Date().toISOString();
  server.emit('response', { payload: currentTime });
}, 1);

客户端代码如下：

const coap = require('coap');
const client = coap.request('coap://localhost');

client.on('response', (res) => {
  console.log(`Received ${res.code} response with payload: ${res.payload.toString()}`);
});

client.end();

当服务器有新的响应数据时，客户端将会打印出来。