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【Apache Kafka】代码范例

时间:2013-10-24 16:28来源:www.chengxuyuans.com 点击:
【Apache Kafka】代码实例

前提:

  • 已经配置好kafka。若未安装,可以参照【Apache Kafka】安装升级指南
  • 已在eclipse里面安装scala插件。Eclipse Kepler中在Help->Eclipse Markectplace中搜索Scalar,然后安装即可。
  • 使用maven构建kafka测试project在eclipse中。
  • 创建topic:在kafka的安装目录下执行bin/kafka-create-topic.sh --zookeeper 192.168.20.99:2181 --replica 1 --partition 1 --topic test
  • 启动consumer:在kafka的安装目录下执行bin/kafka-console-consumer.sh --zookeeper 192.168.20.99:2181 --topic test --from-beginning

pom.xml文件如下:

所有kafka依赖的jar包都在com.sksamuel.kafka下面。其中kafka使用的版本是0.8.0-beta1,kafka是2.10。

<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>com.iflytek.cpcloud.kafka</groupId>
  <artifactId>kafkatest</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>kafkatest</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.14</version>
		</dependency>
		<dependency>
			<groupId>com.sksamuel.kafka</groupId>
			<artifactId>kafka_2.10</artifactId>
			<version>0.8.0-beta1</version>
		</dependency>
	</dependencies>
</project>

  • 然后写一个kafka producer的测试程序如下:

package com.iflytek.cpcloud.kafka.kafkatest;

import java.util.Properties;

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

/**
 * Test the Kafka Producer
 * @author jcsong2
 *
 */
public class ProducerTest {
	public static void main(String[] args) {
		Properties props = new Properties();
		props.put("zk.connect", "192.168.20.99:2181");
		props.put("serializer.class", "kafka.serializer.StringEncoder");
		props.put("metadata.broker.list", "192.168.20.99:9092");
		ProducerConfig config = new ProducerConfig(props);
		Producer<String, String> producer = new Producer<String, String>(config);
		for (int i = 0; i < 10; i++)
			producer.send(new KeyedMessage<String, String>("test", "test" + i));
	}
}
在consuemr端可以看到test0到test9十行输出。


  • 再写一个kafka consumer的测试程序如下:

package com.iflytek.cpcloud.kafka.kafkatest;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;

public class ConsumerTest extends Thread {
	private final ConsumerConnector consumer;
	private final String topic;

	public static void main(String[] args) {
		ConsumerTest consumerThread = new ConsumerTest("test");
		consumerThread.start();
	}

	public ConsumerTest(String topic) {
		consumer = kafka.consumer.Consumer
				.createJavaConsumerConnector(createConsumerConfig());
		this.topic = topic;
	}

	private static ConsumerConfig createConsumerConfig() {
		Properties props = new Properties();
		props.put("zookeeper.connect", "192.168.20.99:2181");
		props.put("group.id", "0");
		props.put("zookeeper.session.timeout.ms", "400000");
		props.put("zookeeper.sync.time.ms", "200");
		props.put("auto.commit.interval.ms", "1000");

		return new ConsumerConfig(props);

	}

	public void run() {
		Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
		topicCountMap.put(topic, new Integer(1));
		Map<String, List<KafkaStream<byte[], byte[]>>> consumerMap = consumer
				.createMessageStreams(topicCountMap);
		KafkaStream<byte[], byte[]> stream = consumerMap.get(topic).get(0);
		ConsumerIterator<byte[], byte[]> it = stream.iterator();
		while (it.hasNext())
			System.out.println(new String(it.next().message()));
	}
}

在kafka-console-producer端输入的数据会回显到eclipse的console中。

以上程序参考kafka-0.8.0-bata1中的example。


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