Apache Kafka’nın Java ile kullanımı

By Mehmet Kılıç Last updated Jul 28, 2018

Merhaba arkadaşlar,
Apache Kafka ile ilgili bilgiyi kurulum ve kullanımı hakkında bir önceki yazımda detaylı deyinmiştik.

Link: http://www.turkishh.com/programlama/kafka-nedir-kurulumu-ve-kullanimi/
Bu yazımda kafka ile javada procuder ve consumer yapan küçük bir uygulama yapacağız. Uygulamamız maven olacak springboot ile yapacağız uygulamamızı.Kafka’yı kullanabilmemiz için Java version 1.8 olması lazım.

Senaryomuz basit prodecure yapacak bir rest servis yazacağız. Servise istek attığımızda messajımızı parametre ile geçeceğiz ve kafka kütüphanelerini kullanarak producer yapacağız ve aynı şekilde producer ettiğimiz mesajımızı consumer edip konsola yazacağız. Ayrıyeten komut satırından da consumer edeceğiz.
İlk önce bağımlılıklarımızı tanımlayalım pom dosyamız şöyle olacak.

pom.xml



<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>io.bilisim</groupId>
    <artifactId>ApacheKafka</artifactId>
    <packaging>jar</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>ApacheKafka</name>
    <url>http://www.turkishh.com</url>
 
 
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.3.5.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka_2.10</artifactId>
            <version>0.8.2.2</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>javax.ws.rs</groupId>
            <artifactId>jsr311-api</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-kafka</artifactId>
            <version>1.1.1.RELEASE</version>
        </dependency>
         
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
         
        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-java-dsl</artifactId>
            <version>1.1.0.RELEASE</version>
        </dependency>
    </dependencies>
 
 
 
 
    <build>
        <finalName>ApacheKafka</finalName>
    </build>
</project>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

<groupId>io.bilisim</groupId>

<artifactId>ApacheKafka</artifactId>

<version>0.0.1-SNAPSHOT</version>

<name>ApacheKafka</name>

<url>http://www.turkishh.com</url>

<java.version>1.8</java.version>

</properties>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-parent</artifactId>

<version>1.3.5.RELEASE</version>

</parent>

<groupId>org.apache.kafka</groupId>

<artifactId>kafka_2.10</artifactId>

</exclusion>

</exclusion>

</exclusions>

</dependency>

<groupId>javax.ws.rs</groupId>

</dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-test</artifactId>

</dependency>

<groupId>org.springframework.integration</groupId>

<artifactId>spring-integration-kafka</artifactId>

<version>1.1.1.RELEASE</version>

</dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-web</artifactId>

</dependency>

<groupId>org.springframework.integration</groupId>

<artifactId>spring-integration-java-dsl</artifactId>

<version>1.1.0.RELEASE</version>

</dependency>

</dependencies>

<build>

<finalName>ApacheKafka</finalName>

</build>

</project>

SpringBoot kullandığımız için uygulamamızı start edecek sınıfı yazıyoruz

Application.java



package io.bilisim;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.integration.config.EnableIntegration;
 
@SpringBootApplication
@EnableIntegration
public class Application {
    private static final Logger LOGGER = LoggerFactory.getLogger(Application.class);
        public static void main(String[] args) {
            LOGGER.info("Starting...");
            SpringApplication.run(Application.class, args);
        }
    }

package io.bilisim;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.integration.config.EnableIntegration;

@SpringBootApplication

@EnableIntegration

public class Application {

private static final Logger LOGGER = LoggerFactory.getLogger(Application.class);

public static void main(String[] args) {

LOGGER.info("Starting...");

SpringApplication.run(Application.class, args);

}

Sonrasında properties dosyamızı resources dizininde altına atıyoruz.

service.properties



kafka.producer.host=localhost
kafka.producer.port=9092
kafka.producer.topic=turkishh.com
kafka.consumer.zookeeperAddress=localhost:2181
kafka.consumer.topic=io.bilisim

kafka.producer.host=localhost

kafka.producer.port=9092

kafka.producer.topic=turkishh.com

kafka.consumer.zookeeperAddress=localhost:2181

kafka.consumer.topic=io.bilisim

Daha sonra KafkaConfig sınıfımızı yazıyoruz .

KafkaConfig.java



package io.bilisim.kafka;
 
 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
 
@Component
public  class KafkaConfig {
    @Value("${kafka.topic:io-bilisim}")
    private String topic;
 
    @Value("${kafka.consumer.zookeeperAddress}")
    private String zookeeperAddress; 
 
    public KafkaConfig() {
    }
 
    public KafkaConfig(String topic, String brokerAddress, String zookeeperAddress) {
        this.topic = topic;
        this.zookeeperAddress = zookeeperAddress;
    }
 
    public String getTopic() {
        return topic;
    }
 
    public String getZookeeperAddress() {
        return zookeeperAddress;
    }
}

package io.bilisim.kafka;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.stereotype.Component;

@Component

public class KafkaConfig {

@Value("${kafka.topic:io-bilisim}")

private String topic;

@Value("${kafka.consumer.zookeeperAddress}")

private String zookeeperAddress;

public KafkaConfig() {

}

public KafkaConfig(String topic, String brokerAddress, String zookeeperAddress) {

this.topic = topic;

this.zookeeperAddress = zookeeperAddress;

}

public String getTopic() {

return topic;

}

public String getZookeeperAddress() {

return zookeeperAddress;

}

Prodecure yapabilmemiz için config sınıfını yazıyoruz.

KafkaProducerConfig.java



package io.bilisim.kafka;
 
import java.util.Properties;
 
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
 
import kafka.javaapi.producer.Producer;
import kafka.producer.ProducerConfig;
 
@Configuration
@PropertySource("classpath:/service.properties")
public class KafkaProducerConfig {
 
    @Value("${kafka.producer.host}")
    private String kafkaHost;
 
    @Value("${kafka.producer.port}")
    private int kafkaPort;
 
    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }
 
    @Bean
    public Producer<String,String> kafkaProducer() {
         
        Properties properties = new Properties();
        properties.put("metadata.broker.list",kafkaHost + ":" + kafkaPort);
        properties.put("serializer.class","kafka.serializer.StringEncoder");;
        ProducerConfig producerConfig = new ProducerConfig(properties);
        Producer<String,String> producer = new Producer<String, String>(producerConfig);
 
        System.out.println("kafka is ready on " + kafkaHost + ":" + kafkaPort);
         
        return producer;
    }
}

package io.bilisim.kafka;

import java.util.Properties;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.PropertySource;

import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;

import kafka.javaapi.producer.Producer;

import kafka.producer.ProducerConfig;

@Configuration

@PropertySource("classpath:/service.properties")

public class KafkaProducerConfig {

@Value("${kafka.producer.host}")

private String kafkaHost;

@Value("${kafka.producer.port}")

private int kafkaPort;

@Bean

public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {

return new PropertySourcesPlaceholderConfigurer();

}

@Bean

public Producer<String,String> kafkaProducer() {

Properties properties = new Properties();

properties.put("metadata.broker.list",kafkaHost + ":" + kafkaPort);

properties.put("serializer.class","kafka.serializer.StringEncoder");;

ProducerConfig producerConfig = new ProducerConfig(properties);

Producer<String,String> producer = new Producer<String, String>(producerConfig);

System.out.println("kafka is ready on " + kafkaHost + ":" + kafkaPort);

return producer;

}

Consumer yapabilmemiz için bir başka config sınıfımızı yazıyoruz.

ConsumerConfiguration.java



package io.bilisim.kafka;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.dsl.IntegrationFlow;
import org.springframework.integration.dsl.IntegrationFlows;
import org.springframework.integration.dsl.SourcePollingChannelAdapterSpec;
import org.springframework.integration.dsl.kafka.Kafka;
import org.springframework.integration.dsl.kafka.KafkaHighLevelConsumerMessageSourceSpec;
import org.springframework.integration.dsl.support.Consumer;
import org.springframework.integration.kafka.support.ZookeeperConnect;
 
@Configuration
public class ConsumerConfiguration {
 
    @Autowired
    private KafkaConfig kafkaConfig;
 
 
    private Log log = LogFactory.getLog(getClass());
 
    @Bean
    IntegrationFlow consumer() {
 
        log.info("starting consumer..  Access Point -> " + "topic : " + kafkaConfig.getTopic() + "zookpeeperaddress : "
                + kafkaConfig.getZookeeperAddress());
 
        KafkaHighLevelConsumerMessageSourceSpec messageSourceSpec = Kafka
                .inboundChannelAdapter(new ZookeeperConnect(this.kafkaConfig.getZookeeperAddress()))
                .consumerProperties(
                        props -> props.put("auto.offset.reset", "smallest").put("auto.commit.interval.ms", "1"))
                .addConsumer("iot-events-group",
                        metadata -> metadata.consumerTimeout(100)
                                .topicStreamMap(m -> m.put(this.kafkaConfig.getTopic(), 1)).maxMessages(10)
                                .valueDecoder(String::new));
 
        Consumer<SourcePollingChannelAdapterSpec> endpointConfigurer = e -> e.poller(p -> p.fixedDelay(100));
 
        return IntegrationFlows.from(messageSourceSpec, endpointConfigurer)
                .<Map<String, List<String>>> handle((payload, headers) -> {
                    payload.entrySet().forEach(e -> log.info(readProducer(payload)));
                    return null;
                }).get();
 
    }
 
 
    public String readProducer(Map<String, List<String>> payload) {
        try {
 
            List<List<String>> values = new ArrayList<List<String>>(payload.values());
            @SuppressWarnings("unchecked")
            ConcurrentHashMap<String, List<String>> value = (ConcurrentHashMap<String, List<String>>) values.get(0);
            for (int i = 0; i < value.get(0).size(); i++) {
     
                               log.info(" producer data : " + value.get(0).get(i));
     
            }
        } catch (Exception e) {
 
            log.info("Ended in failure method ConsumerConfiguration@createEvents " + e.getMessage());
        }
        return "success";
    }
 
}

package io.bilisim.kafka;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.integration.dsl.IntegrationFlow;

import org.springframework.integration.dsl.IntegrationFlows;

import org.springframework.integration.dsl.SourcePollingChannelAdapterSpec;

import org.springframework.integration.dsl.kafka.Kafka;

import org.springframework.integration.dsl.kafka.KafkaHighLevelConsumerMessageSourceSpec;

import org.springframework.integration.dsl.support.Consumer;

import org.springframework.integration.kafka.support.ZookeeperConnect;

@Configuration

public class ConsumerConfiguration {

@Autowired

private KafkaConfig kafkaConfig;

private Log log = LogFactory.getLog(getClass());

@Bean

IntegrationFlow consumer() {

log.info("starting consumer.. Access Point -> " + "topic : " + kafkaConfig.getTopic() + "zookpeeperaddress : "

+ kafkaConfig.getZookeeperAddress());

KafkaHighLevelConsumerMessageSourceSpec messageSourceSpec = Kafka

.inboundChannelAdapter(new ZookeeperConnect(this.kafkaConfig.getZookeeperAddress()))

.consumerProperties(

props -> props.put("auto.offset.reset", "smallest").put("auto.commit.interval.ms", "1"))

.addConsumer("iot-events-group",

metadata -> metadata.consumerTimeout(100)

.topicStreamMap(m -> m.put(this.kafkaConfig.getTopic(), 1)).maxMessages(10)

.valueDecoder(String::new));

Consumer<SourcePollingChannelAdapterSpec> endpointConfigurer = e -> e.poller(p -> p.fixedDelay(100));

return IntegrationFlows.from(messageSourceSpec, endpointConfigurer)

.<Map<String, List<String>>> handle((payload, headers) -> {

payload.entrySet().forEach(e -> log.info(readProducer(payload)));

return null;

}).get();

}

public String readProducer(Map<String, List<String>> payload) {

try {

List<List<String>> values = new ArrayList<List<String>>(payload.values());

@SuppressWarnings("unchecked")

ConcurrentHashMap<String, List<String>> value = (ConcurrentHashMap<String, List<String>>) values.get(0);

for (int i = 0; i < value.get(0).size(); i++) {

log.info(" producer data : " + value.get(0).get(i));

}

} catch (Exception e) {

log.info("Ended in failure method ConsumerConfiguration@createEvents " + e.getMessage());

}

return "success";

}

Kafka producer yapabilmemiz için producer servisimizi yazıyoruz.

KafkaProducerService.java



package io.bilisim.kafka;
 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Service;
 
import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
 
@Service
@PropertySource("classpath:/service.properties")
public class KafkaProducerService {
     
    private Log log = LogFactory.getLog(getClass());
    @Value("${kafka.producer.topic}")
    String kafkaTopic;
     
 
    @Autowired
    Producer<String,String> producer;
     
 
     
    /**
    * Kafka writes value
    *
    * @param   data  - The type parameter String 
    * @return  the method return type is void
    * @author  mkilic 
    */
    public void setMessage(String data){
        KeyedMessage<String, String> message =new KeyedMessage<String, String>(kafkaTopic,data);
         
        producer.send(message);
    }
     
}

package io.bilisim.kafka;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.context.annotation.PropertySource;

import org.springframework.stereotype.Service;

import kafka.javaapi.producer.Producer;

import kafka.producer.KeyedMessage;

@Service

@PropertySource("classpath:/service.properties")

public class KafkaProducerService {

private Log log = LogFactory.getLog(getClass());

@Value("${kafka.producer.topic}")

String kafkaTopic;

@Autowired

Producer<String,String> producer;

/**

* Kafka writes value

* @param data - The type parameter String

* @return the method return type is void

* @author mkilic

public void setMessage(String data){

KeyedMessage<String, String> message =new KeyedMessage<String, String>(kafkaTopic,data);

producer.send(message);

}

Contoller sınıfımızı yazıyoruz.

KafkaProducerController.java



package io.bilisim.controller;
 
import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
 
import com.turkishh.kafka.KafkaProducerService;
 
@RestController
@RequestMapping("/kafka")
@PropertySource("classpath:/service.properties")
public class KafkaProducerController {
 
    @Autowired
    KafkaProducerService kafkaProducerService;
 
    @RequestMapping(value = "/producer/{message}", method = RequestMethod.GET)
    @Consumes({ MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN, MediaType.APPLICATION_XML })
    @Produces({ MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN, MediaType.APPLICATION_XML })
    public String producer(@PathVariable("message") String message) {
 
        kafkaProducerService.setMessage(message);
 
        return "true";
    }
 
}

package io.bilisim.controller;

import javax.ws.rs.Consumes;

import javax.ws.rs.Produces;

import javax.ws.rs.core.MediaType;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.PropertySource;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.bind.annotation.RestController;

import com.turkishh.kafka.KafkaProducerService;

@RestController

@RequestMapping("/kafka")

@PropertySource("classpath:/service.properties")

public class KafkaProducerController {

@Autowired

KafkaProducerService kafkaProducerService;

@RequestMapping(value = "/producer/{message}", method = RequestMethod.GET)

@Consumes({ MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN, MediaType.APPLICATION_XML })

@Produces({ MediaType.APPLICATION_JSON, MediaType.TEXT_PLAIN, MediaType.APPLICATION_XML })

public String producer(@PathVariable("message") String message) {

kafkaProducerService.setMessage(message);

return "true";

}

Uygulamamızı çalıştırdığımız zaman servisimize istek atmamız lazım producer işlemi için

http://localhost:8080/kafka/producer/<mesajımız>

Producer ettiğimizde çıktısını konsola bakabilirz yada bir önceki yazımdaki consumer ekranından görebiliriz.

Apache Kafka’nın Java ile kullanımı

pom.xml

Application.java

service.properties

KafkaConfig.java

KafkaProducerConfig.java

ConsumerConfiguration.java

KafkaProducerService.java

KafkaProducerController.java

çıktısı:

konsol çıktısı:

Proje Linki : ProjectsRelatedToKafka-master