<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head> <body> <script src="https://cdn.bootcss.com/paho-mqtt/1.0.2/mqttws31.min.js"></script> <script> client = new Paho.MQTT.Client("broker.emqx.io", Number(8083), "websockets-test");//建立客户端实例 client.connect({onSuccess:onConnect});//连接服务器并注册连接成功处理事件 function onConnect() { console.log("onConnected"); topic = 'mytopic'; //订阅的主题 client.subscribe(topic);//订阅主题 console.log("subscribed"); //发送消息 } 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) { if (responseObject.errorCode !== 0) { // console.log("onConnectionLost:"+responseObject.errorMessage); console.log("连接已断开"); } } function onMessageArrived(message) { console.log("收到消息:"+message.payloadString); console.log("主题："+message.destinationName); } </script> </body> </html>