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https://issues.apache.org/jira/browse/SPARK-20238?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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rayu yuan updated SPARK-20238:
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Summary: Is the JavaDirectKafkaWordCount example correct for Spark version
2.1? (was: Is the JavaKafkaWordCount example correct for Spark version 2.1?)
> Is the JavaDirectKafkaWordCount example correct for Spark version 2.1?
> -----------------------------------------------------------------------
>
> Key: SPARK-20238
> URL: https://issues.apache.org/jira/browse/SPARK-20238
> Project: Spark
> Issue Type: Question
> Components: Examples, ML
> Affects Versions: 2.1.0
> Reporter: rayu yuan
>
> My question is
> https://github.com/apache/spark/blob/master/examples/src/main/java/org/apache/spark/examples/streaming/JavaKafkaWordCount.java
> correct?
> I'm pretty new to both Spark and Java. I wanted to find an example of Spark
> Streaming using Java, streaming from Kafka. The JavaKafkaWordCount at
> https://github.com/apache/spark/blob/master/examples/src/main/java/org/apache/spark/examples/streaming/JavaKafkaWordCount.java
> looked to be perfect.
> However, when I tried running it, I found a couple of issues that I needed to
> overcome.
> 1. This line was unnecessary:
> {code}
> StreamingExamples.setStreamingLogLevels();
> {code}
> Having this line in there (and the associated import) caused me to go looking
> for a dependency spark-examples_2.10 which of no real use to me.
> 2. After running it, this line:
> {code}
> JavaPairReceiverInputDStream<String, String> messages =
> KafkaUtils.createStream(jssc, args[0], args[1], topicMap);
> {code}
> Appeared to throw an error around logging:
> {code}
> Exception in thread "main" java.lang.NoClassDefFoundError:
> org/apache/spark/Logging
> at java.lang.ClassLoader.defineClass1(Native Method)
> at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
> at
> java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
> at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
> at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
> at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
> at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
> at java.security.AccessController.doPrivileged(Native Method)
> at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
> at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
> at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
> at
> org.apache.spark.streaming.kafka.KafkaUtils$.createStream(KafkaUtils.scala:91
> at
> org.apache.spark.streaming.kafka.KafkaUtils$.createStream(KafkaUtils.scala:66
> at
> org.apache.spark.streaming.kafka.KafkaUtils$.createStream(KafkaUtils.scala:11
> at
> org.apache.spark.streaming.kafka.KafkaUtils.createStream(KafkaUtils.scala)
> at
> main.java.com.cm.JavaKafkaWordCount.main(JavaKafkaWordCount.java:72)
> {code}
> To get around this, I found that the code sample in
> https://spark.apache.org/docs/latest/streaming-kafka-0-10-integration.html
> helped me to come up with the right lines to see streaming from Kafka in
> action. Specifically this called createDirectStream instead of createStream.
> So is the example in
> https://github.com/apache/spark/blob/master/examples/src/main/java/org/apache/spark/examples/streaming/JavaKafkaWordCount.java
> or is there something I could have done differently to get that example
> working?
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