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I'm new to Kafka and struggling with a very strange error. Could someone please help in identifying the issue?

The error:

ERROR 26072 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.IllegalArgumentException: Topic cannot be null.] with root cause

java.lang.IllegalArgumentException: Topic cannot be null.
    at org.apache.kafka.clients.producer.ProducerRecord.<init>(ProducerRecord.java:71) ~[kafka-clients-3.0.1.jar:na]

I'm suspecting that somehow it's not able to read the Topic value from the application.yml file but not sure about the reason as it's able to read all other values.

I'm uploading the entire code to Github.

Repo URL: https://github.com/vikram-bhardwaj/KafkaLearning.git

Please help.

Stack trace:

java.lang.IllegalArgumentException: Topic cannot be null.
    at org.apache.kafka.clients.producer.ProducerRecord.<init>(ProducerRecord.java:71) ~[kafka-clients-3.0.1.jar:na]
    at org.apache.kafka.clients.producer.ProducerRecord.<init>(ProducerRecord.java:133) ~[kafka-clients-3.0.1.jar:na]
    at org.springframework.kafka.core.KafkaTemplate.send(KafkaTemplate.java:408) ~[spring-kafka-2.8.5.jar:2.8.5]
    at org.springframework.kafka.core.KafkaTemplate.sendDefault(KafkaTemplate.java:387) ~[spring-kafka-2.8.5.jar:2.8.5]
    at com.learnKafka.producer.LibraryEventProducer.sendLibraryEvents(LibraryEventProducer.java:32) ~[classes/:na]
    at com.learnKafka.controller.LibraryEventsController.postLibraryEvents(LibraryEventsController.java:32) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.19.jar:5.3.19]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:681) ~[tomcat-embed-core-9.0.62.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.19.jar:5.3.19]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.62.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.19.jar:5.3.19]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.19.jar:5.3.19]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.19.jar:5.3.19]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.19.jar:5.3.19]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1743) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
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5
  • May we see more stacktrace? Is that thrown really from the kafkaTemplate.sendDefault(key, value) line of your code? Commented Apr 25, 2022 at 21:39
  • Hi @Artem Bilan added the stack trace to my question Commented Apr 25, 2022 at 21:47
  • Your configuration is defined as spring.kafka.templete.default-topic instead of spring.kafka.template.default-topic in here with the typo for template. That's probably why the topic name is not being assigned. Commented Apr 25, 2022 at 21:47
  • Hi Madhu Bhat Thanks for pointing it out, but it's not due to that. Retried upon update. I have pushed the latest to the repo too and attached a stack trace to the question. Commented Apr 25, 2022 at 22:02
  • I think this all does not make sense any more: see Gary's answer and his investigation. Commented Apr 26, 2022 at 13:26

3 Answers 3

Reset to default
1

I was facing similar issue. I referred - How to set spring boot profile

Seems like intellij is not picking the default topic from yml file and that's why topic was null. Hence the error. It resolved for me without making any changes in sendDefault method.

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0

You have a typo in application.yml - templete Vs. template.

Also, see the error message in the log:

Property 'spring.profiles' imported from location 'file [application.yml]' is invalid and should be replaced with 'spring.config.activate.on-profile' [origin: URL [file:application.yml] - 38:13]

spring:
  config:
    activate:
      on-profile: local
  kafka:
    template:
      default-topic: library-events
    producer:
      bootstrap-servers: localhost:9092, localhost:9093, localhost:9094
      key-serializer: org.apache.kafka.common.serialization.IntegerSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
    admin:
      properties:
       bootstrap.servers: localhost:9092,localhost:9093,localhost:9094
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4 Comments

Hi Gary, Tried your suggestions, still facing the same issue. did this work in your system?
I tested it with your app with no problems with the spelling correction; I can see the defaultTopic field in the template in the debugger.
i used the same, but somehow my defaultTopic field in template is always coming null.
Ask a new question showing your code, config, and version information.
0

I think you should use send method instead of sendDefault for latest versions of spring boot , like this :

kafkaTemplate.sendDefault("topic-name",key,value);
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