mqtt php 和js 的库

php： https://github.com/bluerhinos/phpMQTT
可以直接保存库，不用使用其他工具安装，github里面有例子。

js: https://docs.emqx.com/zh/cloud/latest/connect_to_deployments/js_sdk.html
大概内容：
使用cdn引入<script src="https://unpkg.com/mqtt/dist/mqtt.min.js"></script>

js动态引入并连接服务器。

function loadScript(url,callback) {
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = url;
    script.onload=callback;
    document.head.appendChild(script);
    
}
loadScript("https://unpkg.com/mqtt/dist/mqtt.min.js",function(){
    console.log('ws事件组件加载成功');
    const client = mqtt.connect('ws://10.100.100.174:8083/mqtt', {
      clientId:"web_01",
      username:"",
      password:"",
      // ...other options
    })
    const topic = '/migu/Query'
    const qos = 2
    
    //订阅事件
    client.subscribe(topic, { qos }, (error) => {
      if (error) {
        console.log('subscribe error:', error)
        return
      }
      console.log(`Subscribe to topic '${topic}'`)
    });
    
    // 设置发布的主题、消息及 QoS
    let sendMsg=function(payload,topic){
        if (!topic)topic='/Result';
        const qos = 2
        
        client.publish(topic, payload, { qos }, (error) => {
          if (error) {
            console.error(error)
          }
        })
    }
    sendMsg('客户端已连接','/migu/state');
    client.on('message', (topic, payload) => {
       
      console.log('Received Message: ' + payload.toString() + '\nOn topic: ' + topic,data);
      sendMsg("recv");
    })
});