message has been sent to the system and a reply has been received

src/main/java/ipos/project/DataModellntegration/SimpleSceneIntegration.java

 package ipos.project.DataModellntegration;
 
 import ipos.models.SimpleScene.IposPosition;
-import ipos.project.DataModellntegration.service.impl.ExtMqttServiceImpl;
+import ipos.project.DataModellntegration.service.impl.ExternalPubServiceImpl;
+import ipos.project.mapper.ProtoJsonMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -13,11 +14,15 @@ public class SimpleSceneIntegration {
     private final Logger LOG = LoggerFactory.getLogger(getClass());
 
     @Autowired
-    private ExtMqttServiceImpl mqttService;
+    private ExternalPubServiceImpl mqttService;
 
-    @JmsListener(destination = "/positions", containerFactory = "myFactory")
+    @JmsListener(destination = "/positions", containerFactory = "jmsListenFactory")
     public void receiveMessage(IposPosition pos) {
-        LOG.info("Data integration <" + pos + ">");
-        this.mqttService.publish("test51/subscribe/positions", pos.toString(), 0, false);
+        LOG.trace("Data integration get: " + pos);
+        // we can translate a class into a string using several methods: 1) `.toString()` 2) `JsonFormat` in `ProtoJsonMap`
+        String jsonPos = ProtoJsonMap.toJson(pos);
+        if (jsonPos != null) {
+            this.mqttService.publish("test51/subscribe/positions", jsonPos, 0, false);
+        }
     }
 }

src/main/java/ipos/project/DataModellntegration/service/ExternalCommunicationService.java → src/main/java/ipos/project/DataModellntegration/service/ExternalPubService.java

 package ipos.project.DataModellntegration.service;
 
-public interface ExternalCommunicationService {
+public interface ExternalPubService {
     void publish(final String topic, final String msg , int qos, boolean retained);
-    void subscribe(final String topic, int qos);
 }

src/main/java/ipos/project/DataModellntegration/service/impl/ExtMqttServiceImpl.java → src/main/java/ipos/project/DataModellntegration/service/impl/ExternalPubServiceImpl.java

 package ipos.project.DataModellntegration.service.impl;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-import ipos.project.DataModellntegration.service.ExternalCommunicationService;
+import ipos.project.DataModellntegration.service.ExternalPubService;
 import org.eclipse.paho.client.mqttv3.MqttAsyncClient;
 import org.eclipse.paho.client.mqttv3.MqttException;
 import org.eclipse.paho.client.mqttv3.MqttMessage;
@@ -11,19 +10,15 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
 @Service
-public class ExtMqttServiceImpl implements ExternalCommunicationService {
-
-    private final Logger LOG = LoggerFactory.getLogger(getClass());
+public class ExternalPubServiceImpl implements ExternalPubService {
 
     private final MqttAsyncClient mqttClient;
 
     @Autowired
-    public ExtMqttServiceImpl(MqttAsyncClient mqttClient) {
+    public ExternalPubServiceImpl(MqttAsyncClient mqttClient) {
         this.mqttClient = mqttClient;
     }
 
-    //                                                                                                   ====== Publish
-    //                                                                                          --- Client Json objects
     public void publish(final String topic, final String msg , int qos, boolean retained) {
         MqttMessage mqttMessage = new MqttMessage();
         mqttMessage.setPayload(msg.getBytes());
@@ -36,14 +31,4 @@ public class ExtMqttServiceImpl implements ExternalCommunicationService {
             e.printStackTrace();
         }
     }
-
-    //                                                                                                 ====== Subscribe
-    public void subscribe(final String topic, int qos) {
-        LOG.info(">> Subscribe on " + topic);
-        try {
-            mqttClient.subscribe(topic, qos);
-        } catch (MqttException e) {
-            e.printStackTrace();
-        }
-    }
 }

src/main/java/ipos/project/InitSubscribe.java

-package ipos.project;
-
-import ipos.models.SimpleScene.IposPosition;
-import ipos.project.DataModellntegration.service.impl.ExtMqttServiceImpl;
-import org.eclipse.paho.client.mqttv3.MqttException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.event.ContextRefreshedEvent;
-import org.springframework.context.event.EventListener;
-import org.springframework.stereotype.Component;
-
-@Component
-public class InitSubscribe {
-    private final Logger LOG = LoggerFactory.getLogger(getClass());
-
-    @Autowired
-    private ExtMqttServiceImpl messagingService;
-
-    // intent: example of dynamic subscription
-    @EventListener
-    void initiateSendingMessage(ContextRefreshedEvent event) throws InterruptedException, MqttException {
-        Thread.sleep(6000);
-//        this.messagingService.subscribe("test51/subscribe/positions", 0);
-//        this.messagingService.subscribe("test51/publish/positions", 0);
-
-//        IposPosition pos = IposPosition.newBuilder()
-//                .setX(1)
-//                .setY(2)
-//                .setZ(3)
-//                .setAccuracy((float) 0.9)
-//                .build();
-//
-//        LOG.info(pos.toString());
-    }
-
-}

src/main/java/ipos/project/SensorValueIntegration/api/MqttPositionHandler.java

@@ -32,7 +32,7 @@ public class MqttPositionHandler implements Handler {
             assert pos != null;
             LOG.info("IposPosition received: \n" + pos);
 
-            this.jmsTemplate.convertAndSend("/positions", pos.toByteArray()); // submit position to the internal broker
+            this.jmsTemplate.convertAndSend("/positions", pos); // submit position to the internal broker
             //TODO: fix message converter for the internal broker
         } catch (InvalidProtocolBufferException e) {
             LOG.error("Invalid mqtt message:", e);

src/main/java/ipos/project/UseCaseController/PositionMonitoring.java

@@ -11,7 +11,7 @@ import ipos.models.SimpleScene.IposPosition;
 public class PositionMonitoring {
     private final Logger LOG = LoggerFactory.getLogger(getClass());
 
-    @JmsListener(destination = "/positions123", containerFactory = "myFactory")
+    @JmsListener(destination = "/positions123", containerFactory = "jmsListenFactory")
     public void receiveMessage(IposPosition pos) {
         LOG.info("Received <" + pos + ">");
     }

src/main/java/ipos/project/config/JmsConfig.java

@@ -6,9 +6,6 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.jms.annotation.EnableJms;
 import org.springframework.jms.config.DefaultJmsListenerContainerFactory;
 import org.springframework.jms.config.JmsListenerContainerFactory;
-import org.springframework.jms.support.converter.MappingJackson2MessageConverter;
-import org.springframework.jms.support.converter.MessageConverter;
-import org.springframework.jms.support.converter.MessageType;
 
 import javax.jms.ConnectionFactory;
 
@@ -17,23 +14,13 @@ import javax.jms.ConnectionFactory;
 public class JmsConfig {
 
     @Bean
-    public JmsListenerContainerFactory<?> myFactory(ConnectionFactory connectionFactory,
+    public JmsListenerContainerFactory<?> jmsListenFactory(ConnectionFactory connectionFactory,
                                                            DefaultJmsListenerContainerFactoryConfigurer configurer) {
         DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
         // This provides all boot's default to this factory, including the message converter
         configurer.configure(factory, connectionFactory);
-        // You could still override some of Boot's default if necessary.
         return factory;
     }
 
-    @Bean // Serialize message content to bytes
-    public MessageConverter jacksonJmsMessageConverter() {
-//        MarshallingMessageConverter converter = new MarshallingMessageConverter();
-//        converter.setTargetType(MessageType.BYTES);
-//        return converter;
-        MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
-        converter.setTargetType(MessageType.TEXT);
-        converter.setTypeIdPropertyName("_type");
-        return converter;
-    }
+    // + write custom `MessageConverter`
 }

src/main/java/ipos/project/config/MqttConfig.java

@@ -46,7 +46,7 @@ public class MqttConfig {
                         "\n\tTopic:   " + topic +
                         "\n\tMessage: " + new String(message.getPayload()) +
                         "\n\tQoS:     " + message.getQos() + "\n");
-                messageHandler.getMessageHandler(topic).handle(message);
+                messageHandler.getMessageHandler(topic).handle(message); // classes with @MqttListener annotations
             }
 
             public void connectionLost(Throwable cause) {

src/main/java/ipos/project/config/mqtt/MqttHandlerMap.java

@@ -29,7 +29,7 @@ public class MqttHandlerMap {
 
     private Map<String, Handler> findMessageHandlers() {
         /**
-         * Find beans with @MqttHandler annotation
+         * Find beans with @MqttHandler annotation. One topic = One handler (TODO: one-to-many)
          * @return Map(key=Topic name, value=Handler container)
          */
 

src/main/java/ipos/project/mapper/ProtoJsonMap.java

@@ -17,8 +17,13 @@ public class ProtoJsonMap {
 
     private static final Logger LOG = LoggerFactory.getLogger(ProtoJsonMap.class);
 
-    public static String toJson(MessageOrBuilder messageOrBuilder) throws IOException {
+    public static String toJson(MessageOrBuilder messageOrBuilder) {
+        try {
             return JsonFormat.printer().print(messageOrBuilder);
+        } catch (InvalidProtocolBufferException e) {
+            LOG.error("JSON converting error: ", e);
+            return null;
+        }
     }
 
     @SuppressWarnings({"unchecked", "rawtypes"})

src/main/resources/application.yml

@@ -6,10 +6,15 @@ server:
 
 
 mqtt:
-#  automaticReconnect: true
-#  cleanSession: true
-#  setKeepAliveInterval: 10
-#  connectionTimeout: 20
-  clientId: ipos.project.12312312324324
+  automaticReconnect: true
+  cleanSession: true
+  setKeepAliveInterval: 10
+  connectionTimeout: 20
+  clientId: ipos.project
   hostname: broker.hivemq.com
   port: 1883
+
+spring:
+  activemq:
+    packages:
+      trusted: ipos.models, com.google.protobuf
\ No newline at end of file