Javaフレームワークにおけるミドルウェアを最小限にする利用戦略

// KafkaProducer 示例
    val properties = Properties()
    properties["bootstrap.servers"] = "localhost:9092"

    val producer = KafkaProducer<String, String>(properties)

    val future = producer.send(ProducerRecord("my-topic", "some-data"))
    future.get() // (可选) 等待消息发送完成

// KafkaConsumer 示例
    val properties = Properties()
    properties["bootstrap.servers"] = "localhost:9092"
    properties["group.id"] = "my-group"

    val consumer = KafkaConsumer<String, String>(properties)
    consumer.subscribe(Arrays.asList("my-topic"))

    while (true) {
        val records = consumer.poll(100)
        records.forEach { record ->
            println("${record.key()}: ${record.value()}")
        }
    }

// GreeterServiceGrpc 客户端
    val channel = ManagedChannelBuilder.forAddress("localhost", 9090).usePlaintext().build()
    val client = GreeterServiceGrpc.newBlockingStub(channel)

    val request = HelloRequest.newBuilder().setName("John Doe").build()
    val response = client.sayHello(request)

    println("Received response: ${response.message}")