Kafka Scala消费者代码-打印消耗的记录

Question

当我通过使用url创建以下简单的kafka消费者时：https : //gist.github.com/akhil/6dfda8a04e33eff91a20。

在该链接中，要打印消耗的记录，请使用未识别的单词“ asScala”。好的，告诉我如何迭代返回类型：ConsumerRecord [String，String]，它是poll（）方法的返回类型。

import java.util
import java.util.Properties

import org.apache.kafka.clients.consumer.{ConsumerRecords, KafkaConsumer}

 
object KafkaConsumerEx extends App {

  val topic_name = "newtopic55"
  val consumer_group = "KafkaConsumerBatch"

  val prot = new Properties()
  prot.put("bootstrap.servers","localhost:9092")
  prot.put("group.id",consumer_group)
  prot.put("key.deserializer",  "org.apache.kafka.common.serialization.StringDeserializer")
  prot.put("value.deserializer","org.apache.kafka.common.serialization.StringDeserializer")

  val kfk_consumer = new KafkaConsumer[String,String](prot)
  kfk_consumer.subscribe(util.Collections.singleton(topic_name))
  println("here")

   while(true){
    val consumer_record : ConsumerRecords[String, String]  = kfk_consumer.poll(100)
    println("records count : " + consumer_record.count())
    println("records partitions: " + consumer_record.partitions())
    consumer_record.iterator().


  }

}

感谢在广告中。

Answer 1

您可以轻松地做到这一点

for (record <- consumer_record.iterator()) {
  println(s"Here's your $record")
}

记住要添加此导入：

import scala.collection.JavaConversions._