java mqtt

maven

 <dependency>
            <groupId>org.fusesource.mqtt-client</groupId>
            <artifactId>mqtt-client</artifactId>
            <version>1.14</version>
        </dependency>

server

package com.stonegeek;

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

public class ServerMQTT {
    //tcp:// MQTT安装的服务器地址:MQTT定义的主题
    public static final String HOST="tcp://10.1.166.161:1884";
    //定义一个主题
    public static final String TOPIC = "s/req/device/sendTopAD/deviceId/15187";
    //定义MQTT的id,可以在MQTT服务配置中指定
    private static final String clientid = "server11";


    private MqttClient client;
    private MqttTopic topic11;
    private String userName = "test";
    private String passWord = "test";

    private MqttMessage message;

    public ServerMQTT()throws MqttException {
        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());
        options.setConnectionTimeout(10);
        options.setKeepAliveInterval(20);
        try {
            client.setCallback(new PushCallback());
            client.connect(options);

            topic11 = client.getTopic(TOPIC);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

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

    }

    public static void main(String[] args) throws MqttException{
        ServerMQTT server = new ServerMQTT();
        server.message = new MqttMessage();
        server.message.setQos(1);
        server.message.setRetained(true);
        server.message.setPayload("hello,topic11".getBytes());
        server.publish(server.topic11,server.message);
        System.out.println(server.message.isRetained() + "------ratained状态");
    }
}

client

package com.stonegeek;
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 java.util.concurrent.ScheduledExecutorService;
/**
 * Created by StoneGeek on 2018/6/5.
 * 博客地址：http://www.cnblogs.com/sxkgeek
 */
public class ClientMQTT {
    public static final String HOST="tcp://10.1.166.161:1884";
    public static final String TOPIC = "s/req/device/sendTopAD/deviceId/15187";
    private static final String clientid = "client11";
    private MqttClient client;
    private MqttConnectOptions options;
    private String userName = "test";
    private String passWord = "test";

    private ScheduledExecutorService scheduler;

    private void start() {
        try {
            // host为主机名，clientid即连接MQTT的客户端ID，一般以唯一标识符表示，MemoryPersistence设置clientid的保存形式，默认为以内存保存
            client = new MqttClient(HOST, clientid, new MemoryPersistence());
            // MQTT的连接设置
            options = new MqttConnectOptions();
            // 设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录，这里设置为true表示每次连接到服务器都以新的身份连接
            options.setCleanSession(true);
            // 设置连接的用户名
            options.setUserName(userName);
            // 设置连接的密码
            options.setPassword(passWord.toCharArray());
            // 设置超时时间 单位为秒
            options.setConnectionTimeout(10);
            // 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送个消息判断客户端是否在线，但这个方法并没有重连的机制
            options.setKeepAliveInterval(20);
            // 设置回调
            client.setCallback(new PushCallback());
            MqttTopic topic = client.getTopic(TOPIC);
            //setWill方法，如果项目中需要知道客户端是否掉线可以调用该方法。设置最终端口的通知消息
            options.setWill(topic, "close".getBytes(), 2, true);

            client.connect(options);
            //订阅消息
            int[] Qos  = {1};
            String[] topic1 = {TOPIC};
            client.subscribe(topic1, Qos);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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