creating multiple kafka topics using spring

Question

I am creating a spring-boot application which will create multiple topics. I am taking the list of topic names and configurations from a .csv file. I am trying this code but it can only create a single topic but its not favorable to create multiple topics using this. Is there a way to create multiple topics using spring?

@Bean
public KafkaAdmin admin(){
    Map<String, Object> configs = new HashMap<>();
    configs.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG,"localhost:9092");
    return new KafkaAdmin(configs);
}
@Bean
public NewTopic topic1() {
        NewTopic topic = new NewTopic(String.format("topic%d",1), 10, (short) 1);
        Map<String, String> extraTopicConfig = new HashMap<String, String>();
        extraTopicConfig.put(TopicConfig.CLEANUP_POLICY_CONFIG, "compact");
        extraTopicConfig.put(TopicConfig.MIN_IN_SYNC_REPLICAS_CONFIG, "1");
        topic.configs(extraTopicConfig);
        return topic;

}

Answer 1

I came upon this old question looking for an answer. I solved it like this:

@Configuration
public class TopicCreation {
  final String[] topicNames = new String[] {"topic1", "topic2"};
  final SingletonBeanRegistry beanRegistry;

  public TopicCreation(GenericApplicationContext context) {
    this.beanRegistry = context.getBeanFactory();
  }

  @PostConstruct
  public void createTopics() {
    for (String topic : topicNames) {
      NewTopic newTopic = TopicBuilder.name(topic)
          .replicas(1)
          .partitions(1)
          .build();
      beanRegistry.registerSingleton("topic-" + topic, newTopic);
    }
  }
}

Answer 2

For anyone who is struggling to programmatically create multiple topics or topics on different brokers during start-up, consider using ApplicationRunner. Similar to what has been described in the accepted answer here .