1 package de.juplo.kafka;
3 import lombok.RequiredArgsConstructor;
4 import lombok.extern.slf4j.Slf4j;
5 import org.apache.kafka.clients.consumer.Consumer;
6 import org.apache.kafka.clients.consumer.ConsumerRecord;
7 import org.apache.kafka.clients.consumer.ConsumerRecords;
8 import org.apache.kafka.common.errors.WakeupException;
10 import java.time.Duration;
11 import java.util.Arrays;
12 import java.util.concurrent.Callable;
16 @RequiredArgsConstructor
17 public class SimpleConsumer implements Callable<Integer>
19 private final String id;
20 private final String topic;
21 private final Consumer<String, Message> consumer;
23 private long consumed = 0;
31 log.info("{} - Subscribing to topic {}", id, topic);
32 consumer.subscribe(Arrays.asList(topic));
36 ConsumerRecords<String, Message> records =
37 consumer.poll(Duration.ofSeconds(1));
39 log.info("{} - Received {} messages", id, records.count());
40 for (ConsumerRecord<String, Message> record : records)
51 catch(WakeupException e)
53 log.info("{} - Consumer was signaled to finish its work", id);
58 log.error("{} - Unexpected error: {}, unsubscribing!", id, e.toString());
59 consumer.unsubscribe();
64 log.info("{} - Closing the KafkaConsumer", id);
66 log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
70 private void handleRecord(
78 log.info("{} - {}: {}/{} - {}={}", id, offset, topic, partition, key, value);