NPE in JsonSerializer on template.send if key is null

[Shabin]

I just upgraded from 1.3.4.RELEASE to 2.1.6.RELEASE and on sending a message without any key I am getting NPE.

-java.lang.NullPointerException
	at org.springframework.kafka.support.serializer.JsonSerializer.serialize(JsonSerializer.java:134)
	at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:783)
	at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:768)
	at org.springframework.kafka.core.DefaultKafkaProducerFactory$CloseSafeProducer.send(DefaultKafkaProducerFactory.java:285)
	at org.springframework.kafka.core.KafkaTemplate.doSend(KafkaTemplate.java:348)
	at org.springframework.kafka.core.KafkaTemplate.send(KafkaTemplate.java:181)
	at com.itest.event.distributer.kafka.KafkaEventDistributor.notify(KafkaEventDistributor.java:226)

I am calling the default send() method.
template.send(topicName, eventdata);

I coudn't find any migration steps related to this.

My kafka template configuration:

<bean id="kafkaTemplate" class="org.springframework.kafka.core.KafkaTemplate">
		<constructor-arg>
			<bean class="org.springframework.kafka.core.DefaultKafkaProducerFactory">
				<constructor-arg>
					<map>
						<entry key="bootstrap.servers" value="${event.kafka.url}" />
						<entry key="key.serializer"
							value="org.springframework.kafka.support.serializer.JsonSerializer" />
						<entry key="value.serializer"
							value="com.itest.event.kafka.EventJsonSerializer" />
					</map>
				</constructor-arg>
			</bean>
		</constructor-arg>
	</bean>

[artembilan]

I think this is a good catch and our problem that we don't have this there:

 if (data == null)
            return null;

I mean that is is normal in Kafka world to send null as for value, as well as for key.

Therefore this NPE has to be fixed.

Feel free to contribute it, @Shabin !

Thank you!