<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title>mqtt</title>
<p>官方文档参考网址：https://docs.emqx.io/tutorial/v3/cn/client_dev/javascript.html</p>
<script src="https://unpkg.com/mqtt/dist/mqtt.min.js"></script>
<script>
const TCP_URL = ‘ws://192.168.1.54:8083/mqtt‘
const options = {
// 超时时间
connectTimeout: 4000,
clientId: ‘test1‘,
// 心跳时间
keepalive: 30,
clean: false,
}
const client = mqtt.connect(TCP_URL, options)
// 判断是否已成功连接
if (!client.connected) {
console.log(‘客户端连接成功。。。。。。。‘)
}
var payload = new Object();//传递信息的对象
payload.userName ="wjf3";
payload.password = "123456";
payload.securityCode = "123456789";
//1.订阅主题动作
//client.subscribe(‘/#‘, { qos: 2 }, (error) => {
// if (!error) {
// console.log(‘订阅成功‘)
// }
//})
//2.发布动作
//client.publish(‘/mo/wftdlx/login‘, JSON.stringify(payload),{ qos: 2, rein: false }, (err) => {
// console.log(err || ‘发布成功‘)
//})
//3.取消订阅动作
//client.unsubscribe(‘/#‘,
// (err) => {
// console.log(err || ‘取消订阅成功‘)
// },)
//4.手动断开连接动作
// client.end()
//监控程序=================================================
//1.【clientId】接收【所有订阅主题】的消息
client.on(‘message‘, (topic, message) => {
console.log(‘收到来自‘, topic, ‘的消息:‘, message.toString())
})
//2.成功连接
// client.on(‘connect‘, () => {
//console.log(‘成功连接‘, TCP_URL)
//})
//3.连接错误
client.on(‘error‘, (error) => {
console.log(‘连接失败:‘, error)
//4.重连操作
client.on(‘reconnect‘, (error) => {
console.log(‘正在重连:‘, error)
})
})
</script>
</head>
<body>
</body>
</html>
原文：https://www.cnblogs.com/ynhk/p/11840136.html