Kafka Streams如何在scala中从kafka消息中获取TimeStamp

import org.apache.kafka.streams.scala.ImplicitConversions._
import org.apache.kafka.streams.scala.Serdes._
import org.apache.kafka.streams.scala.StreamsBuilder
import org.apache.kafka.streams.scala.kstream._

object KafkaStreamsExample {
  def main(args: Array[String]): Unit = {
    val builder = new StreamsBuilder()
    val inputTopic = "input-topic"

    val stream: KStream[String, String] = builder.stream[String, String](inputTopic)

    // 使用timestampExtractor方法来从消息中提取时间戳
    val timestampStream: KStream[String, String] = stream
      .selectKey((_, value) => value) // 设置消息的key为value，方便后续操作
      .transformValues(() => new TimestampExtractor) // 使用自定义的时间戳提取器

    // 处理时间戳流
    timestampStream.foreach((key, value) => {
      println(s"Key: $key, Value: $value")
    })

    // 构建Kafka Streams应用程序
    val streams = new KafkaStreams(builder.build(), config)
    streams.start()
  }

  // 自定义时间戳提取器
  class TimestampExtractor extends ValueTransformer[String, String] {
    override def init(context: ProcessorContext): Unit = {}

    override def transform(value: String): String = {
      // 在这里从消息中提取时间戳的逻辑
      val timestamp = // 从消息中提取时间戳的具体实现
      timestamp.toString
    }

    override def close(): Unit = {}
  }
}