def producerFactory: ProducerSettings[K, V] => Producer[K, V] = _ => createKafkaProducer()

in core/src/main/scala/org/apache/pekko/kafka/ProducerSettings.scala [236:415]


  def producerFactory: ProducerSettings[K, V] => Producer[K, V] = _ => createKafkaProducer()

  /**
   * An id string to pass to the server when making requests. The purpose of this is to be able to track the source
   * of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.
   */
  def withClientId(clientId: String): ProducerSettings[K, V] =
    withProperty(ProducerConfig.CLIENT_ID_CONFIG, clientId)

  /**
   * A comma-separated list of host/port pairs to use for establishing the initial connection to the Kafka cluster.
   */
  def withBootstrapServers(bootstrapServers: String): ProducerSettings[K, V] =
    withProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers)

  /**
   * Scala API:
   * The raw properties of the kafka-clients driver, see constants in
   * [[org.apache.kafka.clients.producer.ProducerConfig]].
   */
  def withProperties(properties: Map[String, String]): ProducerSettings[K, V] =
    copy(properties = this.properties ++ properties)

  /**
   * Scala API:
   * The raw properties of the kafka-clients driver, see constants in
   * [[org.apache.kafka.clients.producer.ProducerConfig]].
   */
  def withProperties(properties: (String, String)*): ProducerSettings[K, V] =
    copy(properties = this.properties ++ properties.toMap)

  /**
   * Java API:
   * The raw properties of the kafka-clients driver, see constants in
   * [[org.apache.kafka.clients.producer.ProducerConfig]].
   */
  def withProperties(properties: java.util.Map[String, String]): ProducerSettings[K, V] =
    copy(properties = this.properties ++ properties.asScala)

  /**
   * The raw properties of the kafka-clients driver, see constants in
   * [[org.apache.kafka.clients.producer.ProducerConfig]].
   */
  def withProperty(key: String, value: String): ProducerSettings[K, V] =
    copy(properties = properties.updated(key, value))

  /**
   * Java API: Get a raw property. `null` if it is not defined.
   */
  def getProperty(key: String): String = properties.getOrElse(key, null)

  /**
   * Duration to wait for `KafkaProducer.close` to finish.
   */
  def withCloseTimeout(closeTimeout: FiniteDuration): ProducerSettings[K, V] =
    copy(closeTimeout = closeTimeout)

  /**
   * Java API:
   * Duration to wait for `KafkaProducer.close` to finish.
   */
  def withCloseTimeout(closeTimeout: java.time.Duration): ProducerSettings[K, V] =
    copy(closeTimeout = closeTimeout.asScala)

  /**
   * Call `KafkaProducer.close` on the [[org.apache.kafka.clients.producer.KafkaProducer]] when the producer stage
   * receives a shutdown signal.
   */
  def withCloseProducerOnStop(closeProducerOnStop: Boolean): ProducerSettings[K, V] =
    copy(closeProducerOnStop = closeProducerOnStop)

  /**
   * Tuning parameter of how many sends that can run in parallel.
   */
  def withParallelism(parallelism: Int): ProducerSettings[K, V] =
    copy(parallelism = parallelism)

  /**
   * Fully qualified config path which holds the dispatcher configuration
   * to be used by the producer stages. Some blocking may occur.
   * When this value is empty, the dispatcher configured for the stream
   * will be used.
   */
  def withDispatcher(dispatcher: String): ProducerSettings[K, V] =
    copy(dispatcher = dispatcher)

  /**
   * The time interval to commit a transaction when using the `Transactional.sink` or `Transactional.flow`.
   */
  def withEosCommitInterval(eosCommitInterval: FiniteDuration): ProducerSettings[K, V] =
    copy(eosCommitInterval = eosCommitInterval)

  /**
   * Java API:
   * The time interval to commit a transaction when using the `Transactional.sink` or `Transactional.flow`.
   */
  def withEosCommitInterval(eosCommitInterval: java.time.Duration): ProducerSettings[K, V] =
    copy(eosCommitInterval = eosCommitInterval.asScala)

  /**
   * Scala API.
   * A hook to allow for resolving some settings asynchronously.
   * @since Alpakka Kafka 2.0.0
   */
  def withEnrichAsync(value: ProducerSettings[K, V] => Future[ProducerSettings[K, V]]): ProducerSettings[K, V] =
    copy(enrichAsync = Some(value))

  /**
   * Java API.
   * A hook to allow for resolving some settings asynchronously.
   * @since Alpakka Kafka 2.0.0
   */
  def withEnrichCompletionStage(
      value: java.util.function.Function[ProducerSettings[K, V], CompletionStage[ProducerSettings[K, V]]])
      : ProducerSettings[K, V] =
    copy(enrichAsync = Some((s: ProducerSettings[K, V]) => value.apply(s).asScala))

  /**
   * Replaces the default Kafka producer creation logic with an external producer. This will also set
   * `closeProducerOnStop = false` by default.
   */
  def withProducer(
      producer: Producer[K, V]): ProducerSettings[K, V] =
    copy(producerFactorySync = Some(_ => producer), closeProducerOnStop = false)

  /**
   * Replaces the default Kafka producer creation logic.
   */
  def withProducerFactory(
      factory: ProducerSettings[K, V] => Producer[K, V]): ProducerSettings[K, V] =
    copy(producerFactorySync = Some(factory))

  /**
   * Get the Kafka producer settings as map.
   */
  def getProperties: java.util.Map[String, AnyRef] = properties.asInstanceOf[Map[String, AnyRef]].asJava

  private def copy(
      properties: Map[String, String] = properties,
      keySerializer: Option[Serializer[K]] = keySerializerOpt,
      valueSerializer: Option[Serializer[V]] = valueSerializerOpt,
      closeTimeout: FiniteDuration = closeTimeout,
      closeProducerOnStop: Boolean = closeProducerOnStop,
      parallelism: Int = parallelism,
      dispatcher: String = dispatcher,
      eosCommitInterval: FiniteDuration = eosCommitInterval,
      enrichAsync: Option[ProducerSettings[K, V] => Future[ProducerSettings[K, V]]] = enrichAsync,
      producerFactorySync: Option[ProducerSettings[K, V] => Producer[K, V]] = producerFactorySync)
      : ProducerSettings[K, V] =
    new ProducerSettings[K, V](properties,
      keySerializer,
      valueSerializer,
      closeTimeout,
      closeProducerOnStop,
      parallelism,
      dispatcher,
      eosCommitInterval,
      enrichAsync,
      producerFactorySync)

  override def toString: String = {
    val propertiesWithMandatoryKeys = properties ++ Map(
      ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG -> keySerializerOpt.map(_.getClass).orNull,
      ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG -> valueSerializerOpt.map(_.getClass).orNull)

    val kafkaClients =
      ConfigSettings.serializeAndMaskKafkaProperties(propertiesWithMandatoryKeys,
        new org.apache.kafka.clients.producer.ProducerConfig(_))
    "org.apache.pekko.kafka.ProducerSettings(" +
    s"properties=$kafkaClients," +
    s"keySerializer=$keySerializerOpt," +
    s"valueSerializer=$valueSerializerOpt," +
    s"closeTimeout=${closeTimeout.toCoarsest}," +
    s"closeProducerOnStop=$closeProducerOnStop," +
    s"parallelism=$parallelism," +
    s"dispatcher=$dispatcher," +
    s"eosCommitInterval=${eosCommitInterval.toCoarsest}," +
    s"enrichAsync=${enrichAsync.map(_ => "needs to be applied")}," +
    s"producerFactorySync=${producerFactorySync.map(_ => "is defined").getOrElse("is undefined")})"
  }