java接入mqtt

jar包

      <dependency>
          <groupId>org.eclipse.paho</groupId>
          <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
          <version>1.2.5</version>
      </dependency>  

工具类

package com.tw.tongli.common.mqtt;

/**
 * Mqtt基础配置信息
 * @author
 */
public class MqttConfig {

    /** 订阅消息主题 - 可为多个 现指一个作为示例 */
    public static final String TOPIC = "test/topic"; 
    /** QOS */
    public static final Integer QOS = 2;
    /** 链接地址 */
    public static final String IP_ADDRESS = "tcp://192.168.1.87:1883"; //服务器地址
    /** 用户名 */
    public static final String USERNAME = "admin";
    /** 密码 */
    public static final String PASSWD = "admin";
    /*QoS0 代表，Sender 发送的一条消息，Receiver 最多能收到一次，也就是说 Sender 尽力向 Receiver 发送消息，如果发送失败，也就算了；
    QoS1 代表，Sender 发送的一条消息，Receiver 至少能收到一次，也就是说 Sender 向 Receiver 发送消息，如果发送失败，会继续重试，直到 Receiver 收到消息为止，但是因为重传的原因，Receiver 有可能会收到重复的消息；
    QoS2 代表，Sender 发送的一条消息，Receiver 确保能收到而且只收到一次，也就是说 Sender 尽力向 Receiver 发送消息，如果发送失败，会继续重试，直到 Receiver 收到消息为止，同时保证 Receiver 不会因为消息重传而收到重复的消息。*/
}

package com.tw.tongli.common.mqtt;

import lombok.extern.slf4j.Slf4j;
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;
import org.springframework.stereotype.Component;

/**
 * MQTT处理器
 * @author
 */
@Component
@Slf4j
public class MqttHandle implements MqttCallback {

    /** 日志组件 */
   // private static Logger log = LoggerFactory.getLogger(MqttHandle.class);

    /**
     * 连接丢失
     * @param cause
     */
    @Override
    public void connectionLost(Throwable cause) {
        System.out.println("connection lost：" + cause.getMessage());
        MqttInitialized.reconnection();
    }

    /**
     * 收到消息
     * @param topic
     * @param message
     */
    @Override
    public void messageArrived(String topic, MqttMessage message) {
        log.info("订阅消息已收到...");
        System.out.println("topic:" + topic);
        System.out.println("Qos:" + message.getQos());
        System.out.println("message_content:" + new String(message.getPayload()));
       // System.out.println("Received message: \n  topic：" + topic + "\n  Qos：" + message.getQos() + "\n  payload：" + new String(message.getPayload()));
    }

    /**
     * 消息传递成功
     * @param token
     */
    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        System.out.println("deliveryComplete---------" + token.isComplete());
    }

}

package com.tw.tongli.common.mqtt;

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.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;

/**
 * 初始化MQTT客户端
 * @author
 */
@Component
public class MqttInitialized {

    /** MQTT客户端 */
    private static MqttClient client = null;
    /** 连接选项 */
    private static MqttConnectOptions connOpts = null;
    /** 连接状态 */
    private static Boolean connectStatus = false;
    /** 日志组件 */
    private static Logger log = LoggerFactory.getLogger(MqttInitialized.class);

    /**
     * 获取MQTT客户端连接状态
     * @return
     */
    public static Boolean getConnectStatus() {
        return connectStatus;
    }

    static {
        try {
            // MQTT 连接选项
            connOpts = new MqttConnectOptions();
            // 设置认证信息
            connOpts.setUserName(MqttConfig.USERNAME);
            connOpts.setPassword(MqttConfig.PASSWD.toCharArray());
            //  持久化
            MemoryPersistence persistence = new MemoryPersistence();
            // MQ客户端建立
            client = new MqttClient(MqttConfig.IP_ADDRESS, "tw", persistence);
            // 设置回调
            client.setCallback(new MqttHandle());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * MQTT客户端启动
     */
    @PostConstruct
    public static void connect() {
        try {
            // 建立连接
            client.connect(connOpts);
            connectStatus = client.isConnected();
            log.info("MQTT服务器连接成功~~~");
        } catch (Exception e) {
            connectStatus = client.isConnected();
            log.error("MQTT服务器连接失败!!");
            e.printStackTrace();
            reconnection();
        }
    }

    /**
     * 消息订阅
     * @param topic 主题
     * @param qos   QOS
     */
    public void subscribe(String topic, Integer qos) throws MqttException {
        client.subscribe(topic, qos);
    }

    /**
     * 消息发布
     * @param topic   主题
     * @param message 消息体
     * @param qos     QOS
     */
    public void publish(String topic, String message, Integer qos) throws MqttException {
        MqttMessage mqttMessage = new MqttMessage(message.getBytes());
        mqttMessage.setQos(qos);
        client.publish(topic, mqttMessage);
    }

    /**
     * 断线重连
     */
    public static void reconnection() {
        // 尝试进行重新连接
        while (true) {
            if (MqttInitialized.getConnectStatus()) {
                // 查询连接状态 连接成功则停止重连
                break;
            }
            try {
                log.info("开始进行MQTT服务器连接.......");
                // 进行连接
                connect();
                Thread.sleep(10000);
            } catch (Exception e) {
                log.error("重新连接出现异常");
                e.printStackTrace();
                break;
            }
        }
    }

    /**
     * 测试方法 进行消息订阅
     */
    public void test() {
        try {
            subscribe(MqttConfig.TOPIC, MqttConfig.QOS);
        } catch (MqttException e) {
            throw new RuntimeException(e);
        }
    }

}

测试接口:

@RestController
@RequestMapping("a")
@Slf4j
public class MqttController {

    @Resource
    private MqttInitialized mqttInitialized;



    @GetMapping("b")
    public void receive(@RequestParam (value = "message") String message) throws MqttException {
        mqttInitialized.subscribe("stock",2); //订阅
        mqttInitialized.publish("stock",message,2);//发布
      //  mqttImpl.MqttCallBack();
    }

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总结

ok