Java-Mqtt-ActiveMq(3)

Java-Mqtt-ActiveMq(3)

1、maven

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

2、push-code

**
 * Mqtt服务生产者（推送）
 *
 * @author: zy
 * @date: 2020-09-22 10:34
 */
@Component
public class MqttProduce {

    private MqttProduce() {
    }

    /**
     * ActiveMq服务地址
     */
    private static String MqUrl;

    @Value("${config.MQ-URL}")
    public void setMqUrl(String mqUrl) {
        MqUrl = mqUrl;
    }

    /**
     * ActiveMq客户端id
     */
    private static String MqClinetId;

    @Value("${config.MQ-SUB-CLIENTID}")
    public void setMqClinetId(String mqClinetId) {
        MqClinetId = mqClinetId;
    }

    /**
     * ActiveMq用户名
     */
    private static String MqUserName;

    @Value("${config.MQ-USERNAME}")
    public void setMqUserName(String mqUserName) {
        MqUserName = mqUserName;
    }

    /**
     * ActiveMq用户密码
     */
    private static String MqPassword;

    @Value("${config.MQ-PASSWORD}")
    public void setMqPassword(String mqPassword) {
        MqPassword = mqPassword;
    }

    private static String TOPIC;
    private static String MESSAGE;
    private static MqttClient client;
    private static MqttTopic topic;
    private static MqttMessage message;

    /**
     * Mqtt-推送
     *
     * @param top Topic
     * @param msg Message
     * @throws MqttException
     */
    public static void doPush(String top, String msg) throws MqttException {
        TOPIC = top;
        MESSAGE = msg;
        client = new MqttClient(MqUrl, MqClinetId, new MemoryPersistence());
        connect();
        message = new MqttMessage();
        message.setQos(2);
        //设置是否在服务器中保存消息体
        message.setRetained(true);
        //设置消息的内容
        message.setPayload(MESSAGE.getBytes());
        //发布
        publish(topic, message);
    }

    private static void connect() {
        //1、设置连接属性
        MqttConnectOptions options = new MqttConnectOptions();
        //2、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；换而言之，设置为false时可以客户端可以接受离线消息
        options.setCleanSession(false);
        //3、用户名密码
        options.setUserName(MqUserName);
        options.setPassword(MqPassword.toCharArray());
        //4、设置超时时间
        options.setConnectionTimeout(10);
        //5、设置回话心跳时间
        options.setKeepAliveInterval(20);
        try {
            //6、设置回调类
            client.setCallback(new PushCallback());
            //7、连接
            client.connect(options);
            //8、获取activeMQ上名为TOPIC的topic
            topic = client.getTopic(TOPIC);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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

3、callback-code

/**
 * @author: zy
 * @date: 2020-09-22 15:32
 */
public class PushCallback implements MqttCallback {

    @Override
    public void connectionLost(Throwable cause) {
        // 连接丢失后，一般在这里面进行重连
        System.out.println("连接断开，可以做重连");
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        System.out.println("deliveryComplete---------" + token.isComplete());
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        // subscribe后得到的消息会执行到这里面
        System.out.println("接收消息主题 : " + topic);
        System.out.println("接收消息Qos : " + message.getQos());
        System.out.println("接收消息内容 : " + new String(message.getPayload()));
    }
}