Akka Stream没有直接实现Kafka Stream所实现的连接语义。但是，你可以使用Akka Stream和Alpakka Kafka来实现类似的连接语义。下面是一个示例代码，演示如何使用Akka Stream和Alpakka Kafka实现Kafka连接语义：

import akka.actor.ActorSystem
import akka.kafka.scaladsl.Consumer
import akka.kafka.scaladsl.Producer
import akka.stream.ActorMaterializer
import akka.stream.scaladsl.{Sink, Source}
import org.apache.kafka.clients.consumer.ConsumerRecord
import org.apache.kafka.clients.producer.ProducerRecord
import org.apache.kafka.common.serialization.{ByteArrayDeserializer, StringDeserializer, StringSerializer}

import scala.concurrent.ExecutionContextExecutor

object KafkaConnectionExample extends App {
  implicit val system: ActorSystem = ActorSystem("kafka-connection-example")
  implicit val materializer: ActorMaterializer = ActorMaterializer()
  implicit val executionContext: ExecutionContextExecutor = system.dispatcher

  val bootstrapServers = "localhost:9092"
  val consumerSettings = ConsumerSettings(system, new ByteArrayDeserializer, new StringDeserializer)
    .withBootstrapServers(bootstrapServers)
    .withGroupId("test-group")

  val producerSettings = ProducerSettings(system, new StringSerializer, new StringSerializer)
    .withBootstrapServers(bootstrapServers)

  val topic = "test-topic"

  // Consumer
  val consumerSource = Consumer.plainSource(consumerSettings, Subscriptions.topics(topic))
    .map(_.value())

  // Producer
  val producerSink = Producer.plainSink(producerSettings)

  // Connect the consumer and producer
  val pipeline = consumerSource
    .map(record => new ProducerRecord[String, String](topic, record))
    .runWith(producerSink)

  // Run the pipeline
  pipeline.onComplete {
    case Success(_) =>
      println("Pipeline completed successfully.")
      system.terminate()
    case Failure(ex) =>
      println(s"Pipeline failed with error: ${ex.getMessage}")
      system.terminate()
  }
}

在这个示例中，我们首先设置了Kafka的消费者设置和生产者设置。然后，我们创建了一个消费者Source，将其订阅到指定的主题上。接下来，我们将消费者Source映射为生产者记录，并将其与生产者Sink连接起来。最后，我们运行整个流水线。

请注意，这只是一个简单的示例，你可以根据自己的需求进行修改和扩展。希望这可以帮助你开始使用Akka Stream和Alpakka Kafka来实现Kafka连接语义。