kafka （java API demo）

版本：kafka0.10.2

Producer API

生产者API允许应用程序发送数据流到kafka集群中的topic。

介绍怎么使用producer的例子在这个文档里javadocs

如果你使用maven构建工程的话，要使用producer，你需要在pom文件添加下面的依赖：

<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.10.2.0</version>
</dependency>

Consumer API

消费者API允许应用程序从Kakfa集群中的topic中读取数据流。

介绍怎么使用producer的例子在这个文档里javadocs

consumer需要添加的依赖与producer相同：

<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-clients</artifactId>
<version>0.10.2.0</version>
</dependency>

Streams API

streams API可以改造数据流并输入输出到topics

在javadocs中有详细的例子

Streams API可供使用的额外的文档在这里

要使用kafka streams 需要在pom文件中添加下面的依赖：

<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka-streams</artifactId>
<version>0.10.2.0</version>
</dependency>

一、生产者

package kafka;

import java.util.Properties;

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;

public class UserKafkaProducer extends Thread{
private  final KafkaProducer<Integer,String> producer;
private  final String topic;
private  final Properties props=new Properties();
public UserKafkaProducer(String topic){
//      props.put("metadata.broker.list", "");
props.put("bootstrap.servers", "172.16.31.105:9092");
props.put("acks","all");
props.put("retries",0);
props.put("batch.size",16384);
props.put("linger.ms",1);
props.put("buffer.memory",33554432);
props.put("key.serializer","org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
producer=new KafkaProducer<Integer,String>(props);
this.topic=topic;
}
@Override
public void run() {
int messageNo=1;
while (messageNo<5){
String messageStr=new String("Message_"+messageNo);
System.out.println("Send:"+messageStr);
producer.send(new ProducerRecord<Integer, String>(topic, messageStr));
messageNo++;
try {
sleep(3000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}
}

二、消费者

package kafka;

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 UserKafkaConsumer extends Thread{
private final ConsumerConnector consumer;
private final String topic;

4000
public UserKafkaConsumer(String topic){
consumer=kafka.consumer.Consumer.createJavaConsumerConnector(
createConsumerConfig());
this.topic=topic;
}
private ConsumerConfig createConsumerConfig() {
Properties props=new Properties();
props.put("zookeeper.connect","172.16.31.101:2181,172.16.31.102:2181,172.16.31.103:2181");
props.put("group.id","test-consumer-group");
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();
}
}
}
}

三、启动运行

package kafka;

public class UserKafkaTest {
public static void main(String[] args) {
UserKafkaProducer producerThread=new UserKafkaProducer(KafkaProperties.topic);
producerThread.start();
UserKafkaConsumer consumerThread=new UserKafkaConsumer(KafkaProperties.topic);
consumerThread.start();
}
}

四、可以将配置提取出来

package kafka;

public interface KafkaProperties {
final static String zkConnect = "172.16.31.101:2181,172.16.31.102:2181,172.16.31.103:2181";
final static String groupId="test-consumer-group";
final static String topic ="topic1";
final static String mytopic="mytopic";
final static String kafkaServerURL = "172.16.31.105";
final static int kafkaServerPort = 9093;
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";
}