I have to set up Kafka consumers without using annotations. I have something like this:
public class MyCustomListener<V> implements MessageListener<String, V> {
private final String topicName;
private final Class<V> recordType;
private final String recordTypeName;
private final KafkaProperties props;
private final Logger logger;
private final ConcurrentMessageListenerContainer<String, V> listenerContainer;
public MyCustomListener(
@NotNull String topicName,
@NotNull Class<V> recordType,
@NotNull KafkaProperties props,
Logger logger
) {
this.topicName = topicName;
this.recordType = recordType;
this.recordTypeName = recordType.getSimpleName();
this.props = props;
this.logger = logger;
this.listenerContainer = setup();
}
protected ConcurrentMessageListenerContainer<String, V> setup() {
logger.info("Setting up Kafka listener container for topic {}/{}", topicName, recordTypeName);
var consumerFactory =
new DefaultKafkaConsumerFactory<>(
new HashMap<>() {{
put(BOOTSTRAP_SERVERS_CONFIG, props.getBootstrapServers());
put(GROUP_ID_CONFIG, props.getConsumer().getGroupId());
}},
new StringDeserializer(),
new MyDataDeserializer<>()
);
var containerProps = new ContainerProperties(topicName);
containerProps.setMessageListener(this);
var container = new ConcurrentMessageListenerContainer<>(consumerFactory, containerProps);
container.start();
return container;
}
@Override
public final void onMessage(ConsumerRecord<String, V> record) {
logger.info(
"(#{}) Received {} message in Kafka: ({})",
Thread.currentThread().getId(),
recordTypeName,
record.key()
);
# Actual processing of record code here ...
}
}
The above works for the most part.
How do I associate/provide
RetryTopicConfigurationto the above setup? So that I am able to publish to retry topic and DLT topics and backoff as specified in the retry config.
I am fine with just the retry topic config part being a Bean, say:
public RetryTopicConfiguration myRetryTopicConfig(
KafkaProperties props,
KafkaTemplate<String, MyData> template,
...
) {
return RetryTopicConfigurationBuilder
.newInstance()
.fixedBackOff(..)
.useSingleTopicForFixedDelays()
...
.create(template);
}
