[
https://issues.apache.org/jira/browse/BEAM-2704?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16338195#comment-16338195
]
Raghu Angadi commented on BEAM-2704:
------------------------------------
Resolving this as BEAM-2257 is fixed (it still needs to be marked resolved).
> KafkaIO: NPE without key serializer set
> ---------------------------------------
>
> Key: BEAM-2704
> URL: https://issues.apache.org/jira/browse/BEAM-2704
> Project: Beam
> Issue Type: Bug
> Components: sdk-java-extensions
> Reporter: Chris Pettitt
> Assignee: Raghu Angadi
> Priority: Major
>
> The KafkaIO javadoc implies that you do not need to set a Serializer if you
> only want to emit values:
> {code}
> * <p>Often you might want to write just values without any keys to Kafka.
> Use {@code values()} to
> * write records with default empty(null) key:
> *
> * <pre>{@code
> * PCollection<String> strings = ...;
> * strings.apply(KafkaIO.<Void, String>write()
> * .withBootstrapServers("broker_1:9092,broker_2:9092")
> * .withTopic("results")
> * .withValueSerializer(new StringSerializer()) // just need serializer
> for value
> * .values()
> * );
> * }</pre>
> {code}
> However, if you don't set the key serializer then Kafka blows up when trying
> to instantiate the key serializer (in Kafka 0.10.1, at least). It would be
> more convenient if KafkaIO worked as documented and assigned a null
> serializer if values() is used.
> Relevant stack trace:
> {code}
> Caused by: java.lang.NullPointerException
> at
> org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:230)
> at
> org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:163)
> at
> org.apache.beam.sdk.io.kafka.KafkaIO$KafkaWriter.setup(KafkaIO.java:1582)
> at
> org.apache.beam.sdk.io.kafka.KafkaIO$KafkaWriter$DoFnInvoker.invokeSetup(Unknown
> Source)
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
