NONRTRIC - Implement DMaaP mediator producer service in Java

[nonrtric.git] / dmaap-adaptor-java / src / main / java / org / oran / dmaapadapter / tasks / KafkaTopicListener.java

diff --git a/dmaap-adaptor-java/src/main/java/org/oran/dmaapadapter/tasks/KafkaTopicListener.java b/dmaap-adaptor-java/src/main/java/org/oran/dmaapadapter/tasks/KafkaTopicListener.java
index 0452b88..d1045ee 100644 (file)
--- a/dmaap-adaptor-java/src/main/java/org/oran/dmaapadapter/tasks/KafkaTopicListener.java
+++ b/dmaap-adaptor-java/src/main/java/org/oran/dmaapadapter/tasks/KafkaTopicListener.java
@@ -26,7 +26,6 @@ import java.util.Map;
 
 import org.apache.kafka.clients.consumer.ConsumerConfig;
 import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.common.serialization.IntegerDeserializer;
 import org.apache.kafka.common.serialization.StringDeserializer;
 import org.oran.dmaapadapter.configuration.ApplicationConfig;
 import org.oran.dmaapadapter.repository.InfoType;
@@ -48,24 +47,25 @@ public class KafkaTopicListener {
     private static final Logger logger = LoggerFactory.getLogger(KafkaTopicListener.class);
     private final ApplicationConfig applicationConfig;
     private final InfoType type;
-    private final Many<String> output;
+    private Many<String> output;
+    private Disposable topicReceiverTask;
 
     public KafkaTopicListener(ApplicationConfig applicationConfig, InfoType type) {
         this.applicationConfig = applicationConfig;
-
-        final int CONSUMER_BACKPRESSURE_BUFFER_SIZE = 1024 * 10;
-        this.output = Sinks.many().multicast().onBackpressureBuffer(CONSUMER_BACKPRESSURE_BUFFER_SIZE);
-
         this.type = type;
-        startKafkaTopicReceiver();
+        start();
     }
 
     public Many<String> getOutput() {
         return this.output;
     }
 
-    private Disposable startKafkaTopicReceiver() {
-        return KafkaReceiver.create(kafkaInputProperties()) //
+    public void start() {
+        stop();
+        final int CONSUMER_BACKPRESSURE_BUFFER_SIZE = 1024 * 10;
+        this.output = Sinks.many().multicast().onBackpressureBuffer(CONSUMER_BACKPRESSURE_BUFFER_SIZE);
+        logger.debug("Listening to kafka topic: {} type :{}", this.type.getKafkaInputTopic(), type.getId());
+        topicReceiverTask = KafkaReceiver.create(kafkaInputProperties()) //
                 .receive() //
                 .doOnNext(this::onReceivedData) //
                 .subscribe(null, //
@@ -73,7 +73,14 @@ public class KafkaTopicListener {
                         () -> logger.warn("KafkaTopicReceiver stopped"));
     }
 
-    private void onReceivedData(ConsumerRecord<Integer, String> input) {
+    private void stop() {
+        if (topicReceiverTask != null) {
+            topicReceiverTask.dispose();
+            topicReceiverTask = null;
+        }
+    }
+
+    private void onReceivedData(ConsumerRecord<String, String> input) {
         logger.debug("Received from kafka topic: {} :{}", this.type.getKafkaInputTopic(), input.value());
         output.emitNext(input.value(), Sinks.EmitFailureHandler.FAIL_FAST);
     }
@@ -82,17 +89,17 @@ public class KafkaTopicListener {
         logger.error("KafkaTopicReceiver error: {}", t.getMessage());
     }
 
-    private ReceiverOptions<Integer, String> kafkaInputProperties() {
+    private ReceiverOptions<String, String> kafkaInputProperties() {
         Map<String, Object> consumerProps = new HashMap<>();
         if (this.applicationConfig.getKafkaBootStrapServers().isEmpty()) {
             logger.error("No kafka boostrap server is setup");
         }
         consumerProps.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, this.applicationConfig.getKafkaBootStrapServers());
         consumerProps.put(ConsumerConfig.GROUP_ID_CONFIG, "osc-dmaap-adaptor");
-        consumerProps.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class);
+        consumerProps.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
         consumerProps.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
 
-        return ReceiverOptions.<Integer, String>create(consumerProps)
+        return ReceiverOptions.<String, String>create(consumerProps)
                 .subscription(Collections.singleton(this.type.getKafkaInputTopic()));
     }