Using ConcurrentMessageListenerContainer section of reference doc is a bit confusing

[jourteen]

Using ConcurrentMessageListenerContainer section starts with:

The single constructor is similar to the KafkaListenerContainer constructor.

Then just below:

For the first constructor, Kafka distributes the partitions across the consumers using its group management capabilities.

Probably there were multiple constructors in older versions, but there is a single constructor now.

[artembilan]

Yes, we have only one constructor there at the moment:

	/**
	 * Construct an instance with the supplied configuration properties.
	 * The topic partitions are distributed evenly across the delegate
	 * {@link KafkaMessageListenerContainer}s.
	 * @param consumerFactory the consumer factory.
	 * @param containerProperties the container properties.
	 */
	public ConcurrentMessageListenerContainer(ConsumerFactory<? super K, ? super V> consumerFactory,
			ContainerProperties containerProperties) {

The rest of the logic is done against that ContainerProperties:

	private KafkaMessageListenerContainer<K, V> constructContainer(ContainerProperties containerProperties,
			@Nullable TopicPartitionOffset[] topicPartitions, int i) {

		KafkaMessageListenerContainer<K, V> container;
		if (topicPartitions == null) {
			container = new KafkaMessageListenerContainer<>(this, this.consumerFactory, containerProperties); // NOSONAR
		}
		else {
			container = new KafkaMessageListenerContainer<>(this, this.consumerFactory, // NOSONAR
					containerProperties, partitionSubset(containerProperties, i));
		}
		return container;
	}

I believe indeed in some old version we had different constructor with those assigned partitions.

Now the doc has to be fixed.

I guess that For the first constructor, sentence could be changed to:

If the container properties are configured for topics (or topic pattern),  Kafka distributes the partitions across the consumers using its group management capabilities.

Feel free to contribute the fix: https://github.com/spring-projects/spring-kafka/blob/main/CONTRIBUTING.adoc

Thank you!