物联网架构成长之路(32)-SpringBoot集成MQTT客户端

一、前言
　　这里虽然是说MQTT客户端。其实对于服务器来说，这里的一个具有超级权限的MQTT客户端，就可以做很多事情。比如手机APP或者网页或者第三方服务需要发送数据到设备，但是这些又不是设备，又不能让他们连到MQTT。那么就可以通过HTTP请求业务服务器。然后由业务服务器利用这个MQTT客户端进行发送数据。
　　还有，之前好多人问我，怎么保存这些物联网数据，真的要像前面的博客那样，要自己写插件吗？特别麻烦的啊。这里给出的结论是不需要。保存数据，除了写EMQ插件，还可以在EMQ的规则引擎上进行配置Web消息转发【EMQ 3.x 版本】，还有就是这种通过业务服务器订阅根Topic来保存物联网原始数据。
　　这篇博客这讨论如何把MQTT客户端集成到业务服务器上（基于SpringBoot 2.0）。下一篇博客会讲到数据保存到InfluxDB，然后如何通过Grafana进行可视化Dashboard看板模式展示。

二、配置pom.xml，引入第三方库

        <!-- MQTT -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-integration</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-stream</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-mqtt</artifactId>
        </dependency>

三、MQTT客户端代码（Java）

　　MqttDemoApplication.java

package com.wunaozai.mqtt;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.wunaozai.mqtt.tools.MqttPushClient;

@SpringBootApplication
public class MqttDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(MqttDemoApplication.class, args);
        
        test();
    }

    
    private static void test(){
        MqttPushClient.MQTT_HOST = "tcp://mqtt.com:1883";
        MqttPushClient.MQTT_CLIENTID = "client";
        MqttPushClient.MQTT_USERNAME = "username";
        MqttPushClient.MQTT_PASSWORD = "password";
        MqttPushClient client = MqttPushClient.getInstance();
        client.subscribe("/#");
    }
}

　　MqttPushCallback.java

package com.wunaozai.mqtt.tools;

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * MQTT 推送回调
 * @author wunaozai
 * @date 2018-08-22
 */
public class MqttPushCallback implements MqttCallback {
    
    private static final Logger log = LoggerFactory.getLogger(MqttPushCallback.class);

    @Override
    public void connectionLost(Throwable cause) {
        log.info("断开连接，建议重连" + this);
        //断开连接，建议重连
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        //log.info(token.isComplete() + "");
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        log.info("Topic: " + topic);
        log.info("Message: " + new String(message.getPayload()));
    }

}

　　MqttPushClient.java

package com.wunaozai.mqtt.tools;

import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttTopic;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 创建一个MQTT客户端
 * @author wunaozai
 * @date 2018-08-22
 */
public class MqttPushClient {
    
    private static final Logger log = LoggerFactory.getLogger(MqttPushClient.class);
    public static String MQTT_HOST = "";
    public static String MQTT_CLIENTID = "";
    public static String MQTT_USERNAME = "";
    public static String MQTT_PASSWORD = "";
    public static int MQTT_TIMEOUT = 10;
    public static int MQTT_KEEPALIVE = 10;
    
    private MqttClient client;
    private static volatile MqttPushClient mqttClient = null;
    public static MqttPushClient getInstance() {
        if(mqttClient == null) {
            synchronized (MqttPushClient.class) {
                if(mqttClient == null) {
                    mqttClient = new MqttPushClient();
                }
            }
        }
        return mqttClient;
    }
    
    private MqttPushClient() {
        log.info("Connect MQTT: " + this);
        connect();
    }
    
    private void connect() {
        try {
            client = new MqttClient(MQTT_HOST, MQTT_CLIENTID, new MemoryPersistence());
            MqttConnectOptions option = new MqttConnectOptions();
            option.setCleanSession(true);
            option.setUserName(MQTT_USERNAME);
            option.setPassword(MQTT_PASSWORD.toCharArray());
            option.setConnectionTimeout(MQTT_TIMEOUT);
            option.setKeepAliveInterval(MQTT_KEEPALIVE);
            option.setAutomaticReconnect(true);
            try {
                client.setCallback(new MqttPushCallback());
                client.connect(option);
            } catch (Exception e) {
                e.printStackTrace();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 发布主题，用于通知<br>
     * 默认qos为1 非持久化
     * @param topic
     * @param data
     */
    public void publish(String topic, String data) {
        publish(topic, data, 1, false);
    }
    /**
     * 发布
     * @param topic
     * @param data
     * @param qos
     * @param retained
     */
    public void publish(String topic, String data, int qos, boolean retained) {
        MqttMessage message = new MqttMessage();
        message.setQos(qos);
        message.setRetained(retained);
        message.setPayload(data.getBytes());
        MqttTopic mqttTopic = client.getTopic(topic);
        if(null == mqttTopic) {
            log.error("Topic Not Exist");
        }
        MqttDeliveryToken token;
        try {
            token = mqttTopic.publish(message);
            token.waitForCompletion();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 订阅某个主题 qos默认为1
     * @param topic
     */
    public void subscribe(String topic) {
        subscribe(topic, 1);
    }
    /**
     * 订阅某个主题
     * @param topic
     * @param qos
     */
    public void subscribe(String topic, int qos) {
        try {
            client.subscribe(topic, qos);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

四、MQTT客户端代码（C#）
　　为了下下篇博客Grafana有数据可以展示，我需要开发一个PC小工具【设备仿真】，用来模拟设备一直发送数据。这里就不对C#开发进行过多的说明了。通过nuget，引入第三方mqtt库。这个工具是我现在开发平台工具链的一个小工具。至于里面的Payload协议，可以不用管。读者可以根据自己的业务制定自己的通信协议。

　　部分C#代码（连接服务器与发送数据）

using MQTTClient.Model;
using MQTTnet;
using MQTTnet.Core;
using MQTTnet.Core.Client;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace MQTTClient
{
    public partial class MainPage : Form
    {
        public MainPage()
        {
            InitializeComponent();
            init();
        }
        private void init()
        {
            txtusername.Text = "";
            txtpassword.Text = "";
            txtclientid.Text = "";
            txttopic.Text = "iot/UUID/device/devicepub/update";
        }

        IMqttClient client = null;
        private async Task ConnectMqttServerAsync()
        {
            if(client == null)
            {
                client = new MqttClientFactory().CreateMqttClient() as MqttClient;
                client.ApplicationMessageReceived += mqttClientApplicationMessageReceived;
                client.Connected += mqttClientConnected;
                client.Disconnected += mqttClientDisconnected;
            }
            try
            {
                await client.DisconnectAsync();
                var option = getMQTTOption();
                await client.ConnectAsync(option);
            }catch(Exception e)
            {
                Invoke((new Action(() =>
                {
                    lblStatus.Text = "连接服务器失败: " + e.Message;
                })));
            }
        }
        private void mqttClientDisconnected(object sender, EventArgs e)
        {
            Invoke((new Action(() =>
            {
                lblStatus.Text = "连接服务器失败: ERROR";
            })));
        }
        private void mqttClientConnected(object sender, EventArgs e)
        {
            Invoke((new Action(() =>
            {
                lblStatus.Text = "连接服务器成功";
            })));
        }
        private void mqttClientApplicationMessageReceived(object sender, MqttApplicationMessageReceivedEventArgs e)
        {
            //本工具部收数据
            throw new NotImplementedException();
        }

        private void btnconnect_Click(object sender, EventArgs e)
        {
            Task.Run(async () => { await ConnectMqttServerAsync(); });
        }
        private void btndisconnect_Click(object sender, EventArgs e)
        {
            client.DisconnectAsync();
        }
        private void btnsendone_Click(object sender, EventArgs e)
        {
            sendPayload();
        }
        private void btnsendts_Click(object sender, EventArgs e)
        {
            timer1.Interval = Convert.ToInt32(txttime.Text);
            timer1.Enabled = true;
        }
        private void btnstopts_Click(object sender, EventArgs e)
        {
            timer1.Enabled = false;
        }
        private void timer1_Tick(object sender, EventArgs e)
        {
            sendPayload();
        }
        private int sendPayload()
        {
            if (client.IsConnected == false)
            {
                return -1;
            }
            PayloadModel payload = getPayload();
            string json = JsonConvert.SerializeObject(payload, Formatting.Indented);
            txtview.Text = json;
            string topic = txttopic.Text;
            var msg = new MqttApplicationMessage(topic, Encoding.Default.GetBytes(json),
                MQTTnet.Core.Protocol.MqttQualityOfServiceLevel.AtMostOnce, false);
            client.PublishAsync(msg);
            lblSendStatus.Text = "发送: " + DateTime.Now.ToLongTimeString();
            return 0;
        }

        private MqttClientTcpOptions getMQTTOption()
        {
            MqttClientTcpOptions option = new MqttClientTcpOptions();
            string hostname = txthostname.Text;
            string[] host_port = hostname.Split(':');
            int port = 1883;
            if(host_port.Length >= 2)
            {
                hostname = host_port[0];
                port = Convert.ToInt32(host_port[1]);
            }
            option.Server = hostname;
            option.ClientId = txtclientid.Text;
            option.UserName = txtusername.Text;
            option.Password = txtpassword.Text;
            option.Port = port;
            option.CleanSession = true;
            return option;
        }

        private PayloadModel getPayload()
        {
            PayloadModel payload = new PayloadModel();
            //略
            return payload;
        }

        Random rand1 = new Random(System.DateTime.Now.Millisecond);
        private int getRandomNum()
        {
            int data = rand1.Next(0, 100);
            return data;
        }

        int linenum = 0;
        Random rand2 = new Random(System.DateTime.Now.Millisecond);
        private int getLineNum()
        {
            int f = rand2.Next(0, 100);
            int data = rand2.Next(0, 5);
            if(f % 2 == 1)
            {
                linenum += data;
            }
            else
            {
                linenum -= data;
            }
            return linenum;
        }

    }
}

本文地址: https://www.cnblogs.com/wunaozai/p/11147841.html