Kafka java实例代码
2017年08月14日 15:15:30 _kairui 阅读数：5892
工程准备
1、首先搭建Kafka集群环境，这里我们kafka的集群环境已经搭建好的，详情参考：
http://blog.csdn.net/liulihui1988/article/details/77099022
2、搭建Maven工程，普通工程需要导入相关的依赖包，想必Maven工程相对简单，如下图：
这里写图片描述
kafka Maven项目 pom.xml 文件，执行添加一下依赖代码
<!-- Kafka 依赖包-->
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.10</artifactId>
<version>0.8.2.0</version>
</dependency>
Kafka java实例代码
消息生产者代码示例
package com.jxl.cloub.kafka;
import java.util.Date;
import java.util.Properties;
import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;
/**
* 消息生产者代码示例
*
*/
public class ProducerDemo {
public static void main(String[] args) {
int events=100;
// 设置配置属性
Properties props = new Properties();
props.put("metadata.broker.list","centos-node6:19092,centos-node7:19092,centos-node8:19092");
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.jxl.cloub.kafka.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
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 = "10.1.6." + 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>(
"test", ip, msg);
producer.send(data);
}
System.out.println("耗时:" + (System.currentTimeMillis() - start));
// 关闭producer
producer.close();
}
}
消息消费者代码示例
package com.jxl.cloub.kafka;
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;
/**
* 消息消费者代码示例
*
*/
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 = { "centos-node7:2181", "0", "test", "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();
}
}
分区Partitioner类示例
package com.jxl.cloub.kafka;
import kafka.producer.Partitioner;
import kafka.utils.VerifiableProperties;
/**
* Partitioner类示例
*
*/
public class PartitionerDemo implements Partitioner{
public PartitionerDemo(VerifiableProperties props) {}
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;
}
}
消息处理类
package com.jxl.cloub.kafka;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
/**
*
*消息处理类
*/
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;
}
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);
}
}
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