Kafka入门实例

kafka安装过程

kafka安装过程参考：Windows系统下搭建Kafka

工程目录

pom文件

<?xml version="1.0" encoding="UTF-8"?>

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>cesi.kafka</groupId>
  <artifactId>kafkaDemo</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>kafkaDemo</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <dependency>
      <groupId>org.apache.kafka</groupId >
      <artifactId>kafka_2.10</artifactId >
      <version>0.8.0</version>
    </dependency>
    
  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

生产者

package cesi.kafka.producer;

import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;

import java.util.Properties;

public class KafkaProducer {
    private final Producer<String, String> producer;
    public final static String TOPIC = "mumu";

    private KafkaProducer() {
        Properties props = new Properties();
        //此处配置的是kafka的端口
        props.put("metadata.broker.list", "127.0.0.1:9092");
        props.put("zk.connect", "127.0.0.1:2181");

        //配置value的序列化类
        props.put("serializer.class", "kafka.serializer.StringEncoder");
        //配置key的序列化类
        props.put("key.serializer.class", "kafka.serializer.StringEncoder");

        props.put("request.required.acks", "-1");

        producer = new Producer<String, String>(new ProducerConfig(props));
    }

    void produce() {
        int messageNo = 1000;
        final int COUNT = 10000;

        while (messageNo < COUNT) {
            String key = String.valueOf(messageNo);
            String data = "kafka producer message " + key;
            producer.send(new KeyedMessage<String, String>(TOPIC, key, data));
            System.out.println(data);
            messageNo++;
        }
    }

    public static void main(String[] args) {
        new KafkaProducer().produce();
    }

}

右键：Run ‘KafkaProducer.main()’

执行结果：

消费者

package cesi.kafka.consumer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import cesi.kafka.producer.KafkaProducer;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.serializer.StringDecoder;
import kafka.utils.VerifiableProperties;

public class KafkaConsumer {
    private final ConsumerConnector consumer;

    private KafkaConsumer() {
        Properties props = new Properties();
        // zookeeper 配置
        props.put("zookeeper.connect", "127.0.0.1:2181");

        // group 代表一个消费组
        props.put("group.id", "muGroup");

        // zk连接超时
        props.put("zookeeper.session.timeout.ms", "4000");
        props.put("zookeeper.sync.time.ms", "200");
        props.put("rebalance.max.retries", "5");
        props.put("rebalance.backoff.ms", "1200");


        props.put("auto.commit.interval.ms", "1000");
        props.put("auto.offset.reset", "smallest");
        // 序列化类
        props.put("serializer.class", "kafka.serializer.StringEncoder");

        ConsumerConfig config = new ConsumerConfig(props);

        consumer = kafka.consumer.Consumer.createJavaConsumerConnector(config);
    }

    void consume() {
        Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
        topicCountMap.put(KafkaProducer.TOPIC, new Integer(1));

        StringDecoder keyDecoder = new StringDecoder(new VerifiableProperties());
        StringDecoder valueDecoder = new StringDecoder(new VerifiableProperties());

        Map<String, List<KafkaStream<String, String>>> consumerMap = consumer.createMessageStreams(topicCountMap, keyDecoder, valueDecoder);
        KafkaStream<String, String> stream = consumerMap.get(KafkaProducer.TOPIC).get(0);
        ConsumerIterator<String, String> it = stream.iterator();
        while (it.hasNext())
            System.out.println("kafka consumer message " + "<<<" + it.next().message() + ">>>");
    }

    public static void main(String[] args) {
        new KafkaConsumer().consume();
    }


}

右键：Run ‘KafkaConsumer.main()’

执行结果：

监控页面

监控页面参考：Kafka web监控KafkaOffsetMonitor