@Bean
public ProducerFactory<Integer, String> producerFactory() {
    return new DefaultKafkaProducerFactory<>(producerConfigs());
}

consumer:
  group-id: group_id
  auto-offset-reset: earliest
  key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
  value-deserializer: io.confluent.kafka.serializers.KafkaAvroDeserializer
  properties:
    specific.avro.reader: true

Arrays use the type name "array" and support a single attribute:
items: the schema of the array's items.

        {
           "type": "array",
           "items": "long"
        }

        {
           "type": "array",
           "items": {
                "name": "ids",
                "type": "long"
           }
        }