bash-4.3# ./kafka-consumer-groups.sh --bootstrap-server localhost:9092 --describe --group test
Note: This will only show information about consumers that use the Java consumer API (non-ZooKeeper-based consumers).

Consumer group 'test' has no active members.

TOPIC         PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG  CONSUMER-ID  HOST  CLIENT-ID
test_topic    0          42              43              1    -            -     -

public void consumeMessages() {
    Properties props = new Properties();
    props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
    props.put(ConsumerConfig.GROUP_ID_CONFIG, "test");
    props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
    props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

    try (KafkaConsumer < String, String > kafkaConsumer = new KafkaConsumer < > (props)) {
        kafkaConsumer.subscribe(Collections.singletonList("test_topic"));
        ConsumerRecords < String, String > consumerRecords = kafkaConsumer.poll(5000);
        for (ConsumerRecord < String, String > consumerRecord: consumerRecords) {
            System.out.printf("offset = %d, message = %s%n", consumerRecord.offset(), consumerRecord.value());
        }
    }
}