I am attempting to define a simple message flow in Spring Integration that reads from one channel and then dumps the messages into a Kafka queue. To do this, I am using spring-integration-kafka. The problem is I get an EvaluationContext
error I can't decipher.
Here is my configuration in XML:
<int:channel id="myStreamChannel"/>
<int:gateway id="myGateway" service-interface="com.myApp.MyGateway" >
<int:method name="process" request-channel="myStreamChannel"/>
</int:gateway>
<int:channel id="activityOutputChannel"/>
<int:transformer input-channel="myStreamChannel" output-channel="activityOutputChannel" ref="activityTransformer"/>
<int-kafka:outbound-channel-adapter id="kafkaOutboundChannelAdapter"
kafka-producer-context-ref="kafkaProducerContext"
auto-startup="false"
channel="activityOutputChannel"
topic="my-test"
message-key-expression="header.messageKey">
<int:poller fixed-delay="1000" time-unit="MILLISECONDS" receive-timeout="0" task-executor="taskExecutor"/>
</int-kafka:outbound-channel-adapter>
<task:executor id="taskExecutor"
pool-size="5-25"
queue-capacity="20"
keep-alive="120"/>
<int-kafka:producer-context id="kafkaProducerContext" producer-properties="producerProperties">
<int-kafka:producer-configurations>
<int-kafka:producer-configuration broker-list="kafkaserver.com:9092"
key-class-type="java.lang.String"
value-class-type="java.lang.String"
topic="my-test"
key-encoder="stringEncoder"
value-encoder="stringEncoder"
compression-codec="snappy"/>
</int-kafka:producer-configurations>
</int-kafka:producer-context>
When I run my application via Spring Boot, I get this exception:
Error creating bean with name 'org.springframework.integration.kafka.outbound.KafkaProducerMessageHandler#0': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: [Assertion failed] - this argument is required; it must not be null
This is the offending line in the stack trace:
at org.springframework.integration.kafka.outbound.KafkaProducerMessageHandler.onInit(KafkaProducerMessageHandler.java:68)
Here is what happens at Line 68:
Assert.notNull(this.evaluationContext);
So the EvaluationContext
is null. I have no idea why.
By the way, when I replace the Kafka endpoint with a trivial stdout
endpoint to print the message body, everything works fine.
Can you tell me what is wrong with my Kafka endpoint configuration that there is no EvaluationContext
available?