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 -;
             }
             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 ;
         }

         private MqttClientTcpOptions getMQTTOption()
         {
             MqttClientTcpOptions option = new MqttClientTcpOptions();
             string hostname = txthostname.Text;
             string[] host_port = hostname.Split(':');
             int port = ;
             if(host_port.Length >= )
             {
                 hostname = host_port[];
                 port = Convert.ToInt32(host_port[]);
             }
             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(, );
             return data;
         }

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

     }
 }

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