<dependency>
    <groupId>io.vertx</groupId>
    <artifactId>vertx-mqtt-client</artifactId>
    <version>4.2.2</version> <!-- Пожалуйста, измените номер версии в соответствии с реальной ситуацией. -->
</dependency>

import io.vertx.core.AbstractVerticle;
import io.vertx.core.Vertx;
import io.vertx.core.buffer.Buffer;
import io.vertx.mqtt.MqttClient;
import io.vertx.mqtt.MqttClientOptions;

public class MqttClientVerticle extends AbstractVerticle {

    @Override
    public void start() {
        MqttClientOptions options = new MqttClientOptions()
            .setAutoKeepAlive(true)
            .setKeepAliveTimeSeconds(10);

        MqttClient mqttClient = MqttClient.create(vertx, options);

        mqttClient.connect(1883, "mqtt.eclipse.org", ar -> {
            if (ar.succeeded()) {
                System.out.println("Connected to the MQTT broker");

                // Подписаться на тему
                mqttClient.subscribe("your_topic", 0, subAck -> {
                    if (subAck.succeeded()) {
                        System.out.println("Subscribed to topic");
                    } else {
                        System.err.println("Failed to subscribe to topic");
                    }
                });

                // Опубликовать сообщение
                mqttClient.publish("your_topic", Buffer.buffer("Hello, MQTT!"), 0, false, false, pubAck -> {
                    if (pubAck.succeeded()) {
                        System.out.println("Message published");
                    } else {
                        System.err.println("Failed to publish message");
                    }
                });
            } else {
                System.err.println("Failed to connect to the MQTT broker");
            }
        });
    }

    public static void main(String[] args) {
        Vertx vertx = Vertx.vertx();
        vertx.deployVerticle(new MqttClientVerticle());
    }
}

javac -cp ".:your/dependency/jars/*" YourMqttClientVerticle.java
java -cp ".:your/dependency/jars/*" YourMqttClientVerticle