Kafka的Producer和Consumer的示例(使用java语言)

我使用的kafka版本是：0.7.2

jdk版本是：1.6.0_20

http://kafka.apache.org/07/quickstart.html官方给的示例并不是很完整，以下代码是经过我补充的并且编译后能运行的。

Producer Code

import java.util.*;
import kafka.message.Message;
import kafka.producer.ProducerConfig;
import kafka.javaapi.producer.Producer;
import kafka.javaapi.producer.ProducerData;

public class ProducerSample {


	public static void main(String[] args) {
		ProducerSample ps = new ProducerSample();

		Properties props = new Properties();
		props.put("zk.connect", "127.0.0.1:2181");
		props.put("serializer.class", "kafka.serializer.StringEncoder");

		ProducerConfig config = new ProducerConfig(props);
		Producer producer = new Producer(config);
		ProducerData data = new ProducerData("test-topic", "test-message2");
		producer.send(data);
		producer.close();
	}
}

Consumer Code

import java.nio.ByteBuffer;
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;
import kafka.message.Message;
import kafka.message.MessageAndMetadata;

public class ConsumerSample {

	public static void main(String[] args) {
                // specify some consumer properties
		Properties props = new Properties();
		props.put("zk.connect", "localhost:2181");
		props.put("zk.connectiontimeout.ms", "1000000");
		props.put("groupid", "test_group");

                // Create the connection to the cluster
		ConsumerConfig consumerConfig = new ConsumerConfig(props);
		ConsumerConnector consumerConnector = Consumer.createJavaConsumerConnector(consumerConfig);

                // create 4 partitions of the stream for topic “test-topic”, to allow 4 threads to consume
		HashMap map = new HashMap();
		map.put("test-topic", 4);
		Map>> topicMessageStreams =
				consumerConnector.createMessageStreams(map);
		List> streams = topicMessageStreams.get("test-topic");

                // create list of 4 threads to consume from each of the partitions 
		ExecutorService executor = Executors.newFixedThreadPool(4);

                // consume the messages in the threads
		for (final KafkaStream stream : streams) {
			executor.submit(new Runnable() {
				public void run() {
					for (MessageAndMetadata msgAndMetadata : stream) {
						// process message (msgAndMetadata.message())
						System.out.println("topic: " + msgAndMetadata.topic());
						Message message = (Message) msgAndMetadata.message();
						ByteBuffer buffer = message.payload();
						byte[] bytes = new byte[message.payloadSize()];
						buffer.get(bytes);
						String tmp = new String(bytes);
						System.out.println("message content: " + tmp);
					}
				}
			});
		}

	}
}

分别启动zookeeper,kafka server之后，依次运行Producer,Consumer的代码

运行ProducerSample：

运行ConsumerSample:

由于本人不熟悉java的多线程，将官方给的Consumer Code做点小改动，如下所示：

import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import kafka.consumer.Consumer;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.message.Message;
import kafka.message.MessageAndMetadata;

public class ConsumerSample2 {

	public static void main(String[] args) {
		// specify some consumer properties
		Properties props = new Properties();
		props.put("zk.connect", "localhost:2181");
		props.put("zk.connectiontimeout.ms", "1000000");
		props.put("groupid", "test_group");

		// Create the connection to the cluster
		ConsumerConfig consumerConfig = new ConsumerConfig(props);
		ConsumerConnector consumerConnector = Consumer.createJavaConsumerConnector(consumerConfig);

		HashMap map = new HashMap();
		map.put("test-topic", 1);
		Map>> topicMessageStreams =
				consumerConnector.createMessageStreams(map);
		List> streams = topicMessageStreams.get("test-topic");

		for (final KafkaStream stream : streams) {
			for (MessageAndMetadata msgAndMetadata : stream) {
				// process message (msgAndMetadata.message())
				System.out.println("topic: " + msgAndMetadata.topic());
				Message message = (Message) msgAndMetadata.message();
				ByteBuffer buffer = message.payload();
				byte[] bytes = new byte[message.payloadSize()];
				buffer.get(bytes);
				String tmp = new String(bytes);
				System.out.println("message content: " + tmp);
			}
		}
	}
}

我在Producer端又发送了一条“test-message2”的消息，Consumer收到了两条消息，如下所示：