1.首先搭建起MQTT服務

1.1安裝mosquitto，mosquitto是開源的MQTT代理伺服器，它的Windows安裝包地址：https://mosquitto.org/download/

1.2安裝、配置ActiveMQ

ActiveMQ下載地址：http://activemq.apache.org/components/classic/download/

ActiveMQ操作手冊：http://activemq.apache.org/getting-started#StartingActiveMQStartingActiveMQ

把下載的壓縮包解壓以後，放到自己可以方便找到的目錄。在這個目錄下，進入解壓檔案包的bin目錄，在這個目錄下開啟cmd視窗，輸入activemq start ，按回車MQTT服務啟動成功如下

開啟ActiveMQ的檢視頁面：http://127.0.0.1:8161/admin/，輸入使用者名稱：admin 密碼 ：admin，進入檢視頁面，如下圖。

2.用java實現一個MQTT客戶端，併發布訊息，測試MQTT服務端

2.1 下載mqtt的jar包

地址如下：https://repo.eclipse.org/content/repositories/paho-releases/org/eclipse/paho/

2.2引用官方示例測試，官方示例程式碼如下：

package com.mqtttest;

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
 

import org.eclipse.paho.client.mqttv3.MqttCallback;

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.MqttException;

import org.eclipse.paho.client.mqttv3.MqttMessage;
 

import org.eclipse.paho.client.mqttv3.MqttPersistenceException;

import org.eclipse.paho.client.mqttv3.MqttTopic;

import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;

public class Main {

    public static void main(String[] args) {

        String topic        = "MQTT Examples";

        String content      = "Message from MqttPublishSample";

        int qos             = 2;

        String broker       = "tcp://127.0.0.1:1883";

        String clientId     = "JavaSample";

        MemoryPersistence persistence = new MemoryPersistence();

        try {

            MqttClient sampleClient = new MqttClient(broker, clientId, persistence);

            MqttConnectOptions connOpts = new MqttConnectOptions();

            connOpts.setCleanSession(true);

            System.out.println("Connecting to broker: "+broker);

            sampleClient.connect(connOpts);

            System.out.println("Connected");

            System.out.println("Publishing message: "+content);

            MqttMessage message = new MqttMessage(content.getBytes());

            message.setQos(qos);

            sampleClient.publish(topic, message);

            System.out.println("Message published");

            sampleClient.disconnect();

            System.out.println("Disconnected");

            System.exit(0);

        } catch(MqttException me) {

            System.out.println("reason "+me.getReasonCode());

            System.out.println("msg "+me.getMessage());

            System.out.println("loc "+me.getLocalizedMessage());

            System.out.println("cause "+me.getCause());

            System.out.println("excep "+me);

            me.printStackTrace();

        }

    }

}

執行完畢上面的程式，進入http://localhost:8161/admin/topics.jsp，點選Topics，就可以看到我們釋出的訊息了，如下圖

至此，windows下的 MQTT服務 環境搭建完畢。