1、MQTT Server使用EMQTTD开源库，自行安装配置；
2、JS使用Websocket连接通信。
3、JS的MQTT库为paho-mqtt，git地址：https://github.com/eclipse/paho.mqtt.javascript.git
代码如下：
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title></title> <!-- <script src=“https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.1/mqttws31.js” type=“text/javascript”> </script> --> <script src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.1/mqttws31.min.js" type="text/javascript"></script> <script> var hostname = '127.0.0.1', //'192.168.1.2', port = 8083, clientId = 'client-mao2080', timeout = 5, keepAlive = 100, cleanSession = false, ssl = false, // userName = 'mao2080', // password = '123', topic = '/World'; client = new Paho.MQTT.Client(hostname, port, clientId); //建立客户端实例 var options = { invocationContext: { host: hostname, port: port, path: client.path, clientId: clientId }, timeout: timeout, keepAliveInterval: keepAlive, cleanSession: cleanSession, useSSL: ssl, // userName: userName, // password: password, onSuccess: onConnect, onFailure: function (e) { console.log(e); s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", onFailure()}"; console.log(s); } }; client.connect(options); //连接服务器并注册连接成功处理事件 function onConnect() { console.log("onConnected"); s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", onConnected()}"; console.log(s); client.subscribe(topic); } client.onConnectionLost = onConnectionLost; //注册连接断开处理事件 client.onMessageArrived = onMessageArrived; //注册消息接收处理事件 function onConnectionLost(responseObject) { console.log(responseObject); s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", onConnectionLost()}"; console.log(s); if (responseObject.errorCode !== 0) { console.log("onConnectionLost:" + responseObject.errorMessage); console.log("连接已断开"); } } function onMessageArrived(message) { s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", onMessageArrived()}"; console.log(s); console.log("收到消息:" + message.payloadString); } function send() { var s = document.getElementById("msg").value; if (s) { s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", content:" + (s) + ", from: web console}"; message = new Paho.MQTT.Message(s); message.destinationName = topic; client.send(message); document.getElementById("msg").value = ""; } } var count = 0; function start() { window.tester = window.setInterval(function () { if (client.isConnected) { var s = "{time:" + new Date().Format("yyyy-MM-dd hh:mm:ss") + ", content:" + (count++) + ", from: web console}"; message = new Paho.MQTT.Message(s); message.destinationName = topic; client.send(message); } }, 1000); } function stop() { window.clearInterval(window.tester); } Date.prototype.Format = function (fmt) { //author: meizz var o = { "M+": this.getMonth() + 1, //月份 "d+": this.getDate(), //日 "h+": this.getHours(), //小时 "m+": this.getMinutes(), //分 "s+": this.getSeconds(), //秒 "q+": Math.floor((this.getMonth() + 3) / 3), //季度 "S": this.getMilliseconds() //毫秒 }; if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length)); for (var k in o) if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[ k]) : (("00" + o[k]).substr(("" + o[k]).length))); return fmt; } </script> </head> <body> <input type="text" id="msg" /> <input type="button" value="Send" onclick="send()" /> <input type="button" value="Start" onclick="start()" /> <input type="button" value="Stop" onclick="stop()" /> </body> </html>