MQTT

package com.Carspace.demo.model;

/**
 * Created by danie on 2/28/2019.
 */
import com.Carspace.demo.controller.MainController;
import com.sun.media.sound.ModelAbstractChannelMixer;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
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.springframework.web.servlet.ModelAndView;


public class MqttHandler implements MqttCallback {

    /** The broker url. */
    private static final String brokerUrl = "tcp://localhost:1883";

    /** The client id. */
    private static final String clientId = "CarSpace_Server";

    private String messageVar = "default_message";

    public String getMessageVar(){
        return messageVar;
    }

    public void setMessageVar(String message){
        messageVar=message;
    }

    public void subscribe(String topic) {

        MemoryPersistence persistence = new MemoryPersistence();

        try {

            MqttClient sampleClient = new MqttClient(brokerUrl, clientId, persistence);
            MqttConnectOptions connOpts = new MqttConnectOptions();
            connOpts.setCleanSession(true);

            System.out.println("checking");

            System.out.println("Mqtt Connecting to broker: " + brokerUrl);
            sampleClient.connect(connOpts);
            System.out.println("Mqtt Connected");

            sampleClient.setCallback(this);
            sampleClient.subscribe(topic);

            System.out.println("Subscribed to " + topic);
            System.out.println("Listening");

        } catch (MqttException me) {

            System.out.println("Mqtt reason " + me.getReasonCode());
            System.out.println("Mqtt msg " + me.getMessage());
            System.out.println("Mqtt loc " + me.getLocalizedMessage());
            System.out.println("Mqtt cause " + me.getCause());
            System.out.println("Mqtt excep " + me);
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.eclipse.paho.client.mqttv3.MqttCallback#connectionLost(java.lang.
     * Throwable)
     */
    public void connectionLost(Throwable arg0) {

    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.eclipse.paho.client.mqttv3.MqttCallback#deliveryComplete(org.eclipse.
     * paho.client.mqttv3.IMqttDeliveryToken)
     */
    public void deliveryComplete(IMqttDeliveryToken arg0) {

    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.eclipse.paho.client.mqttv3.MqttCallback#messageArrived(java.lang.
     * String, org.eclipse.paho.client.mqttv3.MqttMessage)
     */
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        System.out.println("Mqtt topic : " + topic);
        System.out.println("Mqtt msg : " + message.toString());
        setMessageVar(message.toString());
    }

}