kafka的简单使用
在eclipse中新建kafka-demo的maven项目，pom.xml依赖如下
<dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.kafka</groupId> <artifactId>kafka_2.9.1</artifactId> <version>0.8.2.1</version> </dependency> <!-- <dependency> <groupId>org.apache.kafka</groupId> <artifactId>kafka-clients</artifactId> <version>0.8.2.1</version> </dependency> --> </dependencies>
ProducerDemo.java
package com.leech.kafka.demo;
import java.util.Date;
import java.util.Properties;
import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;
public class ProducerDemo {
public static void main(String[] args) {
//Random rnd = new Random();
int events=100;
// 设置配置属性
Properties props = new Properties();
//props.put("metadata.broker.list","172.168.63.221:9092,172.168.63.233:9092,172.168.63.234:9092");
props.put("metadata.broker.list","192.168.1.82:9092");
props.put("serializer.class", "kafka.serializer.StringEncoder");
// key.serializer.class默认为serializer.class
props.put("key.serializer.class", "kafka.serializer.StringEncoder");
// 可选配置，如果不配置，则使用默认的partitioner
props.put("partitioner.class", "com.leech.kafka.demo.PartitionerDemo");
// 触发acknowledgement机制，否则是fire and forget，可能会引起数据丢失
// 值为0,1,-1,可以参考
// http://kafka.apache.org/08/configuration.html
props.put("request.required.acks", "1");
ProducerConfig config = new ProducerConfig(props);
// 创建producer
Producer<String, String> producer = new Producer<String, String>(config);
// 产生并发送消息
long start=System.currentTimeMillis();
for (long i = 0; i < events; i++) {
long runtime = new Date().getTime();
String ip = "192.168.2." + i;//rnd.nextInt(255);
String msg = runtime + ",www.example.com," + ip;
//如果topic不存在，则会自动创建，默认replication-factor为1，partitions为0
KeyedMessage<String, String> data = new KeyedMessage<String, String>("page_visits", ip, msg);
producer.send(data);
}
System.out.println("耗时:" + (System.currentTimeMillis() - start));
// 关闭producer
producer.close();
}
}
ConsumerDemo.java
package com.leech.kafka.demo;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import kafka.consumer.Consumer;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
/**
* 详细可以参考：https://cwiki.apache.org/confluence/display/KAFKA/Consumer+Group+Example
*
* @author Fung
*
*/
public class ConsumerDemo {
private final ConsumerConnector consumer;
private final String topic;
private ExecutorService executor;
public ConsumerDemo(String a_zookeeper, String a_groupId, String a_topic) {
consumer = Consumer.createJavaConsumerConnector(createConsumerConfig(a_zookeeper,a_groupId));
this.topic = a_topic;
}
public void shutdown() {
if (consumer != null)
consumer.shutdown();
if (executor != null)
executor.shutdown();
}
public void run(int numThreads) {
Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
topicCountMap.put(topic, new Integer(numThreads));
Map<String, List<KafkaStream<byte[], byte[]>>> consumerMap = consumer
.createMessageStreams(topicCountMap);
List<KafkaStream<byte[], byte[]>> streams = consumerMap.get(topic);
// now launch all the threads
executor = Executors.newFixedThreadPool(numThreads);
// now create an object to consume the messages
//
int threadNumber = 0;
for (final KafkaStream stream : streams) {
executor.submit(new ConsumerMsgTask(stream, threadNumber));
threadNumber++;
}
}
private static ConsumerConfig createConsumerConfig(String a_zookeeper,
String a_groupId) {
Properties props = new Properties();
props.put("zookeeper.connect", a_zookeeper);
props.put("group.id", a_groupId);
props.put("zookeeper.session.timeout.ms", "400");
props.put("zookeeper.sync.time.ms", "200");
props.put("auto.commit.interval.ms", "1000");
return new ConsumerConfig(props);
}
public static void main(String[] arg) {
String[] args = { "192.168.1.82:2181", "group-1", "page_visits", "12" };
String zooKeeper = args[0];
String groupId = args[1];
String topic = args[2];
int threads = Integer.parseInt(args[3]);
ConsumerDemo demo = new ConsumerDemo(zooKeeper, groupId, topic);
demo.run(threads);
try {
Thread.sleep(10000);
} catch (InterruptedException ie) {
}
demo.shutdown();
}
}
ConsumerMsgTask.java
package com.leech.kafka.demo;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
public class ConsumerMsgTask implements Runnable {
private KafkaStream m_stream;
private int m_threadNumber;
public ConsumerMsgTask(KafkaStream stream, int threadNumber) {
m_threadNumber = threadNumber;
m_stream = stream;
}
@Override
public void run() {
ConsumerIterator<byte[], byte[]> it = m_stream.iterator();
while (it.hasNext())
System.out.println("Thread " + m_threadNumber + ": "
+ new String(it.next().message()));
System.out.println("Shutting down Thread: " + m_threadNumber);
}
}
PartitionerDemo.java
package com.leech.kafka.demo;
import kafka.producer.Partitioner;
import kafka.utils.VerifiableProperties;
public class PartitionerDemo implements Partitioner {
public PartitionerDemo(VerifiableProperties props) {
}
@Override
public int partition(Object obj, int numPartitions) {
int partition = 0;
if (obj instanceof String) {
String key=(String)obj;
int offset = key.lastIndexOf('.');
if (offset > 0) {
partition = Integer.parseInt(key.substring(offset + 1)) % numPartitions;
}
}else{
partition = obj.toString().length() % numPartitions;
}
return partition;
}
}