ICS sample producer and consumer

[nonrtric.git] / sample-services / ics-producer-consumer / consumer / src / main / java / com / demo / consumer / consumer / SimpleConsumer.java

diff --git a/sample-services/ics-producer-consumer/consumer/src/main/java/com/demo/consumer/consumer/SimpleConsumer.java b/sample-services/ics-producer-consumer/consumer/src/main/java/com/demo/consumer/consumer/SimpleConsumer.java
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+/*-
+ * ========================LICENSE_START=================================
+ * O-RAN-SC
+ *
+ * Copyright (C) 2024: OpenInfra Foundation Europe
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ========================LICENSE_END===================================
+ */
+
+package com.demo.consumer.consumer;
+
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.errors.WakeupException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import com.demo.consumer.messages.AbstractSimpleKafka;
+import com.demo.consumer.messages.KafkaMessageHandler;
+import com.demo.consumer.messages.MessageHelper;
+import com.demo.consumer.messages.PropertiesHelper;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.Properties;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+import java.time.Duration;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+@Component
+@Setter
+@Getter
+public class SimpleConsumer extends AbstractSimpleKafka {
+    private static final Logger log = LoggerFactory.getLogger(SimpleConsumer.class);
+
+    private KafkaConsumer<String, String> kafkaConsumer = null;
+    private final AtomicBoolean closed = new AtomicBoolean(false);
+
+    @Value("${vars.time:2000}")
+    private int TIME_OUT_MS;
+
+    public void run(String topicName, int numberOfRecords, KafkaMessageHandler callback) throws Exception {
+        Properties props = PropertiesHelper.getProperties();
+        // See if the number of records is provided
+        Optional<Integer> recs = Optional.ofNullable(numberOfRecords);
+
+        // adjust the number of records to get accordingly
+        Integer numOfRecs = recs.orElseGet(() -> Integer.parseInt(props.getProperty("max.poll.records")));
+        props.setProperty("max.poll.records", String.valueOf(numOfRecs));
+
+        // create the consumer
+        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
+
+        // make the consumer available for graceful shutdown
+        setKafkaConsumer(consumer);
+        consumer.assign(Collections.singleton(new TopicPartition(topicName, 0)));
+        //consumer.seekToBeginning(consumer.assignment()); //--from-beginning
+        int recNum = numOfRecs;
+        while (recNum > 0) {
+            ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(TIME_OUT_MS));
+            recNum = records.count();
+            if (recNum == 0) {
+                log.info(MessageHelper.getSimpleJSONObject("No records retrieved").toJSONString());
+                break;
+            }
+
+            for (ConsumerRecord<String, String> record : records) {
+                callback.processMessage(topicName, record);
+                recNum--;
+            }
+        }
+        consumer.close();
+    }
+
+    private void close() throws Exception {
+        if (this.getKafkaConsumer() == null) {
+            log.info(MessageHelper.getSimpleJSONObject("The internal consumer is NULL").toJSONString());
+            return;
+        }
+        log.info(MessageHelper.getSimpleJSONObject("Closing consumer").toJSONString());
+        this.getKafkaConsumer().close();
+    }
+
+    public void runAlways(String topicName, KafkaMessageHandler callback) throws Exception {
+        Properties props = PropertiesHelper.getProperties();
+        // make the consumer available for graceful shutdown
+        setKafkaConsumer(new KafkaConsumer<>(props));
+
+        // keep running forever or until shutdown() is called from another thread.
+        try {
+            getKafkaConsumer().subscribe(List.of(topicName));
+            while (!closed.get()) {
+                ConsumerRecords<String, String> records = getKafkaConsumer().poll(Duration.ofMillis(TIME_OUT_MS));
+                if (records.count() == 0) {
+                    log.info(MessageHelper.getSimpleJSONObject("No records retrieved").toJSONString());
+                }
+
+                for (ConsumerRecord<String, String> record : records) {
+                    callback.processMessage(topicName, record);
+                    log.info(MessageHelper.getSimpleJSONObject("Topic: " + topicName + "Message: " + record.value()).toJSONString());
+                }
+            }
+        } catch (WakeupException e) {
+            // Ignore exception if closing
+            if (!closed.get())
+                throw e;
+        }
+    }
+
+    public void shutdown() {
+        closed.set(true);
+        try {
+            log.info(MessageHelper.getSimpleJSONObject("Shutting down consumer").toJSONString());
+        } catch (Exception e) {
+        }
+        getKafkaConsumer().wakeup();
+    }
+
+    public KafkaConsumer<String, String> getKafkaConsumer() {
+        return kafkaConsumer;
+    }
+
+    public void setKafkaConsumer(KafkaConsumer<String, String> kafkaConsumer) {
+        this.kafkaConsumer = kafkaConsumer;
+    }
+}