java springboot 对接mqtt发消息

一、引入maven

        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.2.2</version>
        </dependency>

二、客户端

import com.ruoyi.common.config.MinioConfigg;
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.springframework.stereotype.Component;

@Component
public class MyMqttClient  {

    public static MqttClient mqttClient = null;
    private static MemoryPersistence memoryPersistence = null;
    private static MqttConnectOptions mqttConnectOptions = null;
    public static String ClientId = (int)((Math.random()*9+1)*10000000)+"";

    public static  void init(String clientId) {
        //初始化连接设置对象
        mqttConnectOptions = new MqttConnectOptions();
        //初始化MqttClient
        if(null != mqttConnectOptions) {
//            true可以安全地使用内存持久性作为客户端断开连接时清除的所有状态
            mqttConnectOptions.setCleanSession(false);
//            设置连接超时
            mqttConnectOptions.setConnectionTimeout(30);
            //设置断开后重新连接
            mqttConnectOptions.setAutomaticReconnect(true);
//            设置持久化方式
            memoryPersistence = new MemoryPersistence();
            if(null != memoryPersistence && null != clientId) {
                try {
                    mqttClient = new MqttClient("tcp://"+MinioConfigg.APP_KEY, clientId,memoryPersistence);
                } catch (MqttException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }else {

            }
        }else {
            System.out.println("mqttConnectOptions对象为空");
        }

        System.out.println(mqttClient.isConnected());
        //设置连接和回调
        if(null != mqttClient) {
            if(!mqttClient.isConnected()) {

//            创建回调函数对象
                MqttRecieveCallback mqttReceriveCallback = new MqttRecieveCallback();
//            客户端添加回调函数
                mqttClient.setCallback(mqttReceriveCallback);
//            创建连接
                try {
                    System.out.println("创建连接");
                    mqttClient.connect(mqttConnectOptions);
                } catch (MqttException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
        }else {
            System.out.println("mqttClient为空");
        }
        System.out.println(mqttClient.isConnected());
    }

    //    关闭连接
    public void closeConnect() {
        //关闭存储方式
        if(null != memoryPersistence) {
            try {
                memoryPersistence.close();
            } catch (MqttPersistenceException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }else {
            System.out.println("memoryPersistence is null");
        }

//        关闭连接
        if(null != mqttClient) {
            if(mqttClient.isConnected()) {
                try {
                    mqttClient.disconnect();
                    mqttClient.close();
                } catch (MqttException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }else {
                System.out.println("mqttClient is not connect");
            }
        }else {
            System.out.println("mqttClient is null");
        }
    }

    //    发布消息
    public void publishMessage(String pubTopic,String message) {

        if(null != mqttClient&& mqttClient.isConnected()) {
            System.out.println("发布消息   "+mqttClient.isConnected());
            System.out.println("id:"+mqttClient.getClientId());
            MqttMessage mqttMessage = new MqttMessage();
            /*QoS0，At most once，至多一次；
        QoS1，At least once，至少一次；
        QoS2，Exactly once，确保只有一次。2比1耗性能*/
            mqttMessage.setQos(2);
            mqttMessage.setPayload(message.getBytes());
            MqttTopic topic = mqttClient.getTopic(pubTopic);

            if(null != topic) {
                try {
                    MqttDeliveryToken publish = topic.publish(mqttMessage);
                    if(!publish.isComplete()) {
                        System.out.println("消息发布成功");
                    }
                } catch (MqttException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

        }else {
            reConnect();
        }

    }
    //    重新连接
    public void reConnect() {
        if(null != mqttClient) {
            if(!mqttClient.isConnected()) {
                if(null != mqttConnectOptions) {
                    try {
                        mqttClient.connect(mqttConnectOptions);
                    } catch (MqttException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }else {
                    System.out.println("mqttConnectOptions is null");
                }
            }else {
                System.out.println("mqttClient is null or connect");
            }
        }else {
            init(ClientId);
        }

    }
    //    订阅主题
    public void subTopic(String topic) {
        if(null != mqttClient&& mqttClient.isConnected()) {
            try {
                mqttClient.subscribe(topic, 1);
            } catch (MqttException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }else {
            System.out.println("mqttClient is error");
        }
    }


    //    清空主题
    public void cleanTopic(String topic) {
        if(null != mqttClient&& !mqttClient.isConnected()) {
            try {
                mqttClient.unsubscribe(topic);
            } catch (MqttException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }else {
            System.out.println("mqttClient is error");
        }
    }
}

三、消费端

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

public class MqttRecieveCallback implements MqttCallback{

    @Override
    public void connectionLost(Throwable cause) {

    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        /*System.out.println("Client 接收消息主题 : " + topic);
        System.out.println("Client 接收消息Qos : " + message.getQos());
        System.out.println("Client 接收消息内容 : " + new String(message.getPayload()));*/


    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {

    }

}

四、程序启动时候开启mqtt   在主程序的Application中

public class XXXApplication implements ApplicationListener<ApplicationReadyEvent>
{
    public static void main(String[] args)
    {
        SpringApplication.run(XXXApplication.class, args);
    }

    @Override
    public void onApplicationEvent(ApplicationReadyEvent event) {
        MyMqttClient.init(MyMqttClient.ClientId);
    }
}