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Kafka java实例代码

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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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