上篇文章中我們搭建了kafka的服務器，並可以使用Kafka的命令行工具創建topic，發送和接收消息。下面我們來搭建kafka的開發環境。
添加依賴
搭建開發環境需要引入kafka的jar包，一種方式是將Kafka安裝包中lib下的jar包加入到項目的classpath中，這種比較簡單了。不過我們使用另一種更加流行的方式：使用maven管理jar包依賴。
創建好maven項目後，在pom.xml中添加以下依賴：
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.10</artifactId>
<version>0.8.2.2</version>
</dependency>添加依賴後如果有兩個jar包的依賴找不到。點擊這裏下載這兩個jar包，解壓後你有兩種選擇，第一種是使用mvn的install命令將jar包安裝到本地倉庫，另一種是直接將解壓後的文件夾拷貝到mvn本地倉庫的com文件夾下，比如我的本地倉庫是d:\mvn,完成後我的目錄結構是這樣的：
配置程序
更新更全的API編程實例點這裏：http://blog.csdn.net/honglei915/article/details/37697655
首先是一個充當配置文件作用的接口,配置了Kafka的各種連接參數：
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 [email protected]
*/
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 [email protected]
*/
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();
}
}
}
}
簡單的發送接收
運行下面這個程序，就可以進行簡單的發送接收消息了：
package com.sohu.kafkademon;
/**
* @author leicui [email protected]
*/
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();
}
}
高級別的consumer
下面是比較負載的發送接收的程序：
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 [email protected]
*/
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();
}
}
}
}