如何在骆驼路线上模拟Kafka消费者endpoint？

Question

我有一个驼峰endpoint，基本上是Kafka消费者从一个主题中读取信息并将其发送到数据库。它工作得很好，但是，我很难对它进行单元测试，因为我无法模拟Kafkaendpoint。有谁能帮我在骆驼路线上嘲笑Kafka的消费者吗？

java prettyprint-override">@Override
public void configure() {    
    from(kafka:eph?brokers=localhost:9092...).routeId("KafkaConsumer")
        .to(direct:updateDatabase)
}

Answer 1

只需在属性中外部化endpointURI（例如，使用Spring属性工具）

from(consumerEndpoint).routeId("KafkaConsumer")

然后在生产配置中，使用真正的endpoint

consumerEndpoint=kafka:eph?brokers=localhost:9092...

而在测试配置中，使用直接endpoint

consumerEndpoint=direct:consumer

这一个很容易从骆驼路线测试中触发

producer.sendBody("direct:consumer", myMessageBody);

Answer 2

要对路线进行单元测试，可以使用标准的驼峰Spring引导测试。在测试期间，Kafka制作人（在Camel看来）可以与直接组件交换，模拟消息可以在那里传递。要查看路由是否正确处理了这些消息，可以使用模拟endpoint。

//Route definition
@Component
public class KafkaRoute extends RouteBuilder {

    public static final String KAFKA_ROUTE_NAME = "kafka-route";

    @Override
    public void configure() throws Exception {
        from("kafka:eph?brokers=localhost:9092").routeId(KAFKA_ROUTE_NAME)
                .log(LoggingLevel.INFO, "Message: ${body}  received on the topic: ${headers[kafka.TOPIC]} ")
                .to("direct:updateDatabase");

        from("direct:updateDatabase").log(LoggingLevel.INFO, "DB Updated.");

    }

}

import java.util.HashMap;
import java.util.Map;

import org.apache.camel.CamelContext;
import org.apache.camel.EndpointInject;
import org.apache.camel.Produce;
import org.apache.camel.ProducerTemplate;
import org.apache.camel.builder.AdviceWithRouteBuilder;
import org.apache.camel.component.kafka.KafkaConstants;
import org.apache.camel.component.mock.MockEndpoint;
import org.apache.camel.test.spring.CamelSpringBootRunner;
import org.apache.camel.test.spring.MockEndpoints;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.annotation.DirtiesContext;

@RunWith(CamelSpringBootRunner.class)
@SpringBootTest
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
@MockEndpoints("direct:*")
public class KafkaRouteTest {

    @Autowired
    CamelContext camelContext;

    @Produce
    ProducerTemplate mockKafkaProducer;

    @EndpointInject("mock:direct:updateDatabase")
    MockEndpoint finalSink;

    @Test
    public void testKafkaRoute() throws Exception {

        //Here we swap the FROM component in the KafkaRoute.KAFKA_ROUTE_NAME with a direct component, direct:kafka-from
        AdviceWithRouteBuilder.adviceWith(camelContext, KafkaRoute.KAFKA_ROUTE_NAME, routeBuilder -> {
            routeBuilder.replaceFromWith("direct:kafka-from");
        });

        Map<String, Object> headers = new HashMap<>();
        headers.put(KafkaConstants.TOPIC, "testTopic");

        //Send mock message to the route
        mockKafkaProducer.sendBodyAndHeaders("direct:kafka-from", "test-body", headers);


        //Assertions. You may do additional assertions with the likes of Mockito
        finalSink.expectedBodiesReceived("test-body");
        finalSink.expectedHeaderReceived(KafkaConstants.TOPIC, "testTopic");
        finalSink.assertIsSatisfied();

    }

}

Camel Kafka组件已经经过单元测试，在代码库中复制所有这些测试是没有意义的。但是，如果你真的想对一个真正的Kafka实例进行测试，你可以使用测试容器。这里有一个完整的例子，来自Camel存储库本身，使用测试容器。