上篇文章中我们搭建了kafka的服务器，并可以使用Kafka的命令行工具创建topic，发送和接收消息。下面我们来搭建kafka的开发环境。
添加依赖
搭建开发环境需要引入kafka的jar包，一种方式是将Kafka安装包中lib下的jar包加入到项目的classpath中，这种比较简单了。不过我们使用另一种更加流行的方式：使用maven管理jar包依赖。
创建好maven项目后，在pom.xml中添加以下依赖：
<dependency>
<groupId> org.apache.kafka</groupId >
<artifactId> kafka_2.10</artifactId >
<version> 0.8.0</ version>
</dependency>
添加依赖后你会发现有两个jar包的依赖找不到。没关系我都帮你想好了，在Linux公社资源站下载这两个jar包。
到Linux公社资源站下载：
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具体下载目录在 /2014年资料/7月/21日/Kafka使用入门教程PDF/
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解压后你有两种选择，第一种是使用mvn的install命令将jar包安装到本地仓库，另一种是直接将解压后的文件夹拷贝到mvn本地仓库的com文件夹下，比如我的本地仓库是d:\mvn,完成后我的目录结构是这样的：
配置程序
首先是一个充当配置文件作用的接口,配置了Kafka的各种连接参数：
package com.sohu.kafkademon;
public interface KafkaProperties
{
final static String zkConnect = "10.22.10.139:2181";
final static String groupId = "group1";
final static String topic = "topic1";
final static String kafkaServerURL = "10.22.10.139";
final static int kafkaServerPort = 9092;
final static int kafkaProducerBufferSize = 64 * 1024;
final static int connectionTimeOut = 20000;
final static int reconnectInterval = 10000;
final static String topic2 = "topic2";
final static String topic3 = "topic3";
final static String clientId = "SimpleConsumerDemoClient";
}
producer
package com.sohu.kafkademon;
import Java.util.Properties;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;
/**
* @author leicui bourne_cui@163.com
*/
public class KafkaProducer extends Thread
{
private final kafka.javaapi.producer.Producer<Integer, String> producer;
private final String topic;
private final Properties props = new Properties();
public KafkaProducer(String topic)
{
props.put("serializer.class", "kafka.serializer.StringEncoder");
props.put("metadata.broker.list", "10.22.10.139:9092");
producer = new kafka.javaapi.producer.Producer<Integer, String>(new ProducerConfig(props));
this.topic = topic;
}
@Override
public void run() {
int messageNo = 1;
while (true)
{
String messageStr = new String("Message_" + messageNo);
System.out.println("Send:" + messageStr);
producer.send(new KeyedMessage<Integer, String>(topic, messageStr));
messageNo++;
try {
sleep(3000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
consumer
package com.sohu.kafkademon;
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;
/**
* @author leicui bourne_cui@163.com
*/
public class KafkaConsumer extends Thread
{
private final ConsumerConnector consumer;
private final String topic;
public KafkaConsumer(String topic)
{
consumer = kafka.consumer.Consumer.createJavaConsumerConnector(
createConsumerConfig());
this.topic = topic;
}
private static ConsumerConfig createConsumerConfig()
{
Properties props = new Properties();
props.put("zookeeper.connect", KafkaProperties.zkConnect);
props.put("group.id", KafkaProperties.groupId);
props.put("zookeeper.session.timeout.ms", "40000");
props.put("zookeeper.sync.time.ms", "200");
props.put("auto.commit.interval.ms", "1000");
return new ConsumerConfig(props);
}
@Override
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("receive：" + new String(it.next().message()));
try {
sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
简单的发送接收
运行下面这个程序，就可以进行简单的发送接收消息了：
package com.sohu.kafkademon;
/**
* @author leicui bourne_cui@163.com
*/
public class KafkaConsumerProducerDemo
{
public static void main(String[] args)
{
KafkaProducer producerThread = new KafkaProducer(KafkaProperties.topic);
producerThread.start();
KafkaConsumer consumerThread = new KafkaConsumer(KafkaProperties.topic);
consumerThread.start();
}
}
高级别的consumer
下面是比较负载的发送接收的程序：
package com.sohu.kafkademon;
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;
/**
* @author leicui bourne_cui@163.com
*/
public class KafkaConsumer extends Thread
{
private final ConsumerConnector consumer;
private final String topic;
public KafkaConsumer(String topic)
{
consumer = kafka.consumer.Consumer.createJavaConsumerConnector(
createConsumerConfig());
this.topic = topic;
}
private static ConsumerConfig createConsumerConfig()
{
Properties props = new Properties();
props.put("zookeeper.connect", KafkaProperties.zkConnect);
props.put("group.id", KafkaProperties.groupId);
props.put("zookeeper.session.timeout.ms", "40000");
props.put("zookeeper.sync.time.ms", "200");
props.put("auto.commit.interval.ms", "1000");
return new ConsumerConfig(props);
}
@Override
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("receive：" + new String(it.next().message()));
try {
sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}