Camel-Kafka component not workingfor error :"because of Brokers must be configured"

Question

Got an error using kafka component for Apache Camel (version 2.19.1),i'm just trying to print incoming messages in topic, my pipeline is so composed:

...
context.addRoutes(new RouteBuilder() {
            public void configure() {
                from("kafka://localhost:9092?topic=test&groupId=testing")
               .to("stream:out");
  context.start();
    }
}

tried with and without "//" in endpoint.

What i got is:

Exception in thread "main" org.apache.camel.FailedToCreateRouteException: Failed to create route route1: Route(route1)[[From[kafka://localhost:9092?topic=test&groupI... because of Brokers must be configured
at org.apache.camel.impl.RouteService.warmUp(RouteService.java:147)
at org.apache.camel.impl.DefaultCamelContext.doWarmUpRoutes(DefaultCamelContext.java:3762)
at org.apache.camel.impl.DefaultCamelContext.safelyStartRouteServices(DefaultCamelContext.java:3669)
at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRoutes(DefaultCamelContext.java:3455)
at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3309)
at org.apache.camel.impl.DefaultCamelContext.access$000(DefaultCamelContext.java:202)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:3093)
at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:3089)
at org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:3112)
at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:3089)
at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61)
at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:3026)
at org.apache.camel.MainApp.main(MainApp.java:60)
Caused by: java.lang.IllegalArgumentException: Brokers must be configured
at org.apache.camel.component.kafka.KafkaConsumer.<init>(KafkaConsumer.java:62)
at org.apache.camel.component.kafka.KafkaEndpoint.createConsumer(KafkaEndpoint.java:76)
at org.apache.camel.impl.EventDrivenConsumerRoute.addServices(EventDrivenConsumerRoute.java:69)
at org.apache.camel.impl.DefaultRoute.onStartingServices(DefaultRoute.java:103)
at org.apache.camel.impl.RouteService.doWarmUp(RouteService.java:172)
at org.apache.camel.impl.RouteService.warmUp(RouteService.java:145)
... 12 more

Process finished with exit code 1

I'm trying to figure it out, but i really don't understand what's the problem, my kafka cluster is a single broker and all is up and running (zookeeper and server), ty for help

Answer 1

Add brokers=localhost:9092 to the consumer uri.

Answer 2

Looking at this example the first part of the URL is the topic and then as parameter you can pass the brokers. So the official documentation seems to be a bit misleading to me.

from("kafka:{{consumer.topic}}?brokers={{kafka.host}}:{{kafka.port}}"
                    + "&maxPollRecords={{consumer.maxPollRecords}}"
                    + "&consumersCount={{consumer.consumersCount}}"
                    + "&seekTo={{consumer.seekTo}}"
                    + "&groupId={{consumer.group}}")
                    .routeId("FromKafka")
                .log("${body}");

But as a general advice: Camel is open source, so you can always have a look at the code and the examples there on github. You can also find those lines of the stack trace you posted there, then track down what's missing.