Spark Streaming：打印JavaInputDStream

目前我正在使用Spark Streaming以及从Kafka读取消息的可能性 . 使用Kafka Producer，我将消息发送到主题，并希望在Spark Streaming的帮助下阅读此主题 .

我使用以下Java代码来查询消息：

package apache_spark_streaming;

import java.util.*;
import org.apache.spark.SparkConf;
import org.apache.spark.streaming.Durations;
import org.apache.spark.streaming.api.java.JavaInputDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;
import org.apache.spark.streaming.kafka010.*;
import org.apache.kafka.clients.consumer.ConsumerRecord;

public final class Spark_Kafka_Example {

private static final String BOOTSTRAP_SERVERS_CONNECTION = "XXXXX";
private static final String SPARK_CONNECTION = "spark://XXXXX:7077";
private static final String TOPIC_NAME = "KafkaTesting1";
private static final Set<String> TOPIC_1 = new HashSet<>(Arrays.asList(TOPIC_NAME.split(",")));

public static Map<String, Object> getProperties() {

    try {
        Map<String, Object> kafkaParams = new HashMap<>();
        kafkaParams.put("bootstrap.servers", BOOTSTRAP_SERVERS_CONNECTION);
        kafkaParams.put("key.deserializer", org.apache.kafka.common.serialization.StringDeserializer.class.getName());
        kafkaParams.put("value.deserializer", org.apache.kafka.common.serialization.StringDeserializer.class.getName());
        kafkaParams.put("group.id", "Stream Testing");
        kafkaParams.put("auto.offset.reset", "earliest");
        kafkaParams.put("enable.auto.commit", false);
        return kafkaParams;
    } 
    catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}
public static void main(String[] args) throws Exception {

    // Create context with a 2 seconds batch interval
    SparkConf sparkConf = new SparkConf().setAppName("Kafka Example").setMaster(SPARK_CONNECTION);   
    JavaStreamingContext sc = new JavaStreamingContext(sparkConf, Durations.seconds(2));

    JavaInputDStream<ConsumerRecord<String, String>> stream = KafkaUtils.createDirectStream(
           sc
           , LocationStrategies.PreferConsistent()
           , ConsumerStrategies.Subscribe(TOPIC_1, getProperties())
    );    

    stream.print();
    sc.start(); 
    sc.awaitTermination();
  }
}

我的问题是我不知道如何在命令行上输出消息 . 也许我只有一个理解问题如何正确使用JavaInputDStreams .

目前我只使用print（）函数作为输出：

17/07/10 16:59:20 INFO JobScheduler：添加了1499698760000 ms的工作时间

我希望你能帮我解决这个“问题” .

Updated 我试过了

stream.foreachRDD(consumerRecordJavaRDD -> {
   consumerRecordJavaRDD.foreach(stringStringConsumerRecord -> {
   //.to get topic name: stringStringConsumerRecord.topic()
   //To get value : stringStringConsumerRecord.value()
  } }