MQTT 發布者訂閱者

添加依賴:

<dependency>
　　<groupId>org.eclipse.paho</groupId>
　　<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
　　<version>1.1.1</version>
</dependency>

MQ發布者:

package com.ra.car.utils;

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;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * MQ發布者
 * 
 * @author lanhao
 * 
 */
public class MQTTPubMsg {
    protected static final Logger logger = LoggerFactory
            .getLogger(MQTTPubMsg.class);
    public static final String HOST = "tcp://10.74.20.43:1883";
    public static final String TOPIC = "toclient/124";
//    public static final String TOPIC125 = "toclient/125";
    private static final String clientid = "server";
    private MqttClient client;
    private MqttTopic topic;
//    private MqttTopic topic125;
    private String userName = "root";
    private String passWord = "Passw0rd";
    private MqttMessage message;

    public MQTTPubMsg() throws MqttException {
        // MemoryPersistence設置clientid的保存形式，默認為以內存保存
        client = new MqttClient(HOST, clientid, new MemoryPersistence());
        connect();
    }

    private void connect() {
        MqttConnectOptions options = new MqttConnectOptions();
        options.setCleanSession(false);
        options.setUserName(userName);
        options.setPassword(passWord.toCharArray());
        // 設置超時時間
        options.setConnectionTimeout(10);
        // 設置會話心跳時間
        options.setKeepAliveInterval(20);
        try {
            client.setCallback(new MQTTPushCallback());
            client.connect(options);
            topic = client.getTopic(TOPIC);
//            topic125 = client.getTopic(TOPIC125);
        } catch (Exception e) {
            logger.error("MQ發布者connect異常......",e);
        }
    }

    public void publish(MqttTopic topic, MqttMessage message)
            throws MqttPersistenceException, MqttException {
        MqttDeliveryToken token = topic.publish(message);
        token.waitForCompletion();
        logger.info("message is published completely! "
                + token.isComplete());
    }

    public static void main(String[] args) throws MqttException {
        MQTTPubMsg server = new MQTTPubMsg();
        String s="這是第一條消息";
        server.message = new MqttMessage();
        server.message.setQos(2);
        server.message.setRetained(true);
        server.message.setPayload(s.getBytes());
        server.publish(server.topic, server.message);
        
        try {
            Thread.sleep(20000);
        } catch (InterruptedException e) {
        }
        for (int i = 0; i < 500; i++) {
            String str = "這是后續循環發送的消息" + i;
            server.message = new MqttMessage();
            server.message.setQos(2);
            server.message.setRetained(true);
            server.message.setPayload(str.getBytes());
            server.publish(server.topic, server.message);

            // 給另外一個topic發送消息
            
             * server.message = new MqttMessage(); server.message.setQos(2);
             * server.message.setRetained(true);
             * server.message.setPayload("給客戶端125推送的信息".getBytes());
             * server.publish(server.topic125, server.message);
             

            logger.info(server.message.isRetained() + "------ratained狀態");
        }
    }

}

 

 

MQ訂閱者:

package com.ra.car.utils;

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

/**
 * MQ訂閱者
 * 
 * @author lanhao
 * 
 */
public class MQTTSubMsg {
    protected static final Logger logger = LoggerFactory
            .getLogger(MQTTSubMsg.class);
    public static final String HOST = "tcp://10.74.20.43:1883";
    public static final String TOPIC = "toclient/124";
    private static final String clientid = "client124";
    private MqttClient client;
    private MqttConnectOptions options;
    private String userName = "root";
    private String passWord = "Passw0rd";

    public void start() {
        try {
            logger.info("SubMsg----->start");
            // host為主機名，clientid即連接MQTT的客戶端ID，一般以唯一標識符表示，MemoryPersistence設置clientid的保存形式，默認為以內存保存
            client = new MqttClient(HOST, clientid, new MemoryPersistence());
            // MQTT的連接設置
            options = new MqttConnectOptions();
            // 設置是否清空session,這里如果設置為false表示服務器會保留客戶端的連接記錄，這里設置為true表示每次連接到服務器都以新的身份連接
            options.setCleanSession(true);
            // 設置連接的用戶名
            options.setUserName(userName);
            // 設置連接的密碼
            options.setPassword(passWord.toCharArray());
            // 設置超時時間 單位為秒
            options.setConnectionTimeout(10);
            // 設置會話心跳時間 單位為秒 服務器會每隔1.5*20秒的時間向客戶端發送個消息判斷客戶端是否在線，但這個方法並沒有重連的機制
            options.setKeepAliveInterval(20);
            // 設置回調
            client.setCallback(new MQTTPushCallback());
            MqttTopic topic = client.getTopic(TOPIC);
            // setWill方法，如果項目中需要知道客戶端是否掉線可以調用該方法。設置最終端口的通知消息
            options.setWill(topic, "close".getBytes(), 2, true);
            client.connect(options);
            // 訂閱消息
            int[] Qos = { 2 };
            String[] topic1 = { TOPIC };
            client.subscribe(topic1, Qos);
        } catch (Exception e) {
            logger.error("MQ訂閱者異常",e);
        }
    }

    public static void main(String[] args) throws MqttException {
        MQTTSubMsg client = new MQTTSubMsg();
        client.start();
    }

}

回調類:

package com.ra.car.utils;

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;

/**
 * 發布消息的回調類
 * 
 * 必須實現MqttCallback的接口並實現對應的相關接口方法CallBack 類將實現 MqttCallBack。
 * 每個客戶機標識都需要一個回調實例。在此示例中，構造函數傳遞客戶機標識以另存為實例數據。 在回調中，將它用來標識已經啟動了該回調的哪個實例。
 * 必須在回調類中實現三個方法
 */
public class MQTTPushCallback implements MqttCallback{
    protected static final Logger logger = LoggerFactory
            .getLogger(MQTTPushCallback.class);
    public void connectionLost(Throwable cause) {
        // 在斷開連接時調用,連接丟失后,一般在這里面進行重連.
        logger.info("連接斷開，可以做重連");
    }

    public void deliveryComplete(IMqttDeliveryToken token) {
        //接收到已經發布的 QoS 1 或 QoS 2 消息的傳遞令牌時調用. 由 MqttClient.connect 激活此回調.
        logger.info("deliveryComplete---------" + token.isComplete());
    }

    public void messageArrived(String topic, MqttMessage message)
            throws Exception {
        // subscribe后得到的消息會執行到這里面
        logger.info("接收消息主題 : " + topic);
        logger.info("接收消息Qos : " + message.getQos());
        logger.info("接收消息內容 : " + new String(message.getPayload()));
    }
}