【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。