Kafka consumer for multiple topic

Question

I have a list of topics (for now it\'s 10) whose size can increase in future. I know we can spawn multiple threads (per topic) to consume from each topic, but in my case if

Answer 1

We can subscribe for multiple topic using following API : consumer.subscribe(Arrays.asList(topic1,topic2), ConsumerRebalanceListener obj)

Consumer has the topic info and we can comit using consumer.commitAsync or consumer.commitSync() by creating OffsetAndMetadata object as follows.

ConsumerRecords records = consumer.poll(long value);
for (TopicPartition partition : records.partitions()) {
    List> partitionRecords = records.records(partition);
    for (ConsumerRecord record : partitionRecords) {
        System.out.println(record.offset() + ": " + record.value());
    }
    long lastOffset = partitionRecords.get(partitionRecords.size() - 1).offset();
    consumer.commitSync(Collections.singletonMap(partition, new OffsetAndMetadata(lastOffset + 1)));
}