<script type="text/javascript" src="mqttws31.js"></script>

var hostname = '',
    port = ,
    clientId = '',
    timeout = ,
    keepAlive = ,
    cleanSession = true,
    ssl = true,
    userName = '',
    password = '',
    topic = '';
client = new Paho.MQTT.Client(hostname, port, clientId);
//建立客戶端例項
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(){
        console.log(12112);
    }
};
client.connect(options);
//連線伺服器並註冊連線成功處理事件
function onConnect() {
    console.log("onConnected");
    client.subscribe(topic);
    //訂閱主題
    //傳送訊息
    message = new Paho.MQTT.Message("");
    message.destinationName = topic;
    // client.send(message);
}
client.onConnectionLost = onConnectionLost;
//註冊連線斷開處理事件
client.onMessageArrived = onMessageArrived;
//註冊訊息接收處理事件
function onConnectionLost(responseObject) {
    if (responseObject.errorCode !== 0) {
        console.log("onConnectionLost:"+responseObject.errorMessage);
        console.log("連線已斷開");
    }
}
function onMessageArrived(message) {
    console.log("收到訊息:"+message.payloadString);
}