kafka的Java客户端示例代码(kafka_2.11-0.8.2.2)

Posted 2020-09-21 静候东风

使用Producer，ConsumerConnector

HelloWorldProducer.java

package cn.ljh.kafka.kafka_helloworld;

import java.util.Date;
import java.util.Properties;
import java.util.Random;

import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;

public class HelloWorldProducer {
    public static void main(String[] args) {
        long events = Long.parseLong(args[0]);
        Random rnd = new Random();
 
        Properties props = new Properties();
        //配置kafka集群的broker地址，建议配置两个以上，以免其中一个失效，但不需要配全，集群会自动查找leader节点。
        props.put("metadata.broker.list", "192.168.137.176:9092,192.168.137.176:9093");
        //配置value的序列化类
        //key的序列化类key.serializer.class可以单独配置，默认使用value的序列化类
        props.put("serializer.class", "kafka.serializer.StringEncoder");
        //配置partitionner选择策略，可选配置
        props.put("partitioner.class", "cn.ljh.kafka.kafka_helloworld.SimplePartitioner");
        props.put("request.required.acks", "1");
 
        ProducerConfig config = new ProducerConfig(props);
 
        Producer<String, String> producer = new Producer<String, String>(config);
 
        for (long nEvents = 0; nEvents < events; nEvents++) { 
               long runtime = new Date().getTime();  
               String ip = "192.168.2." + rnd.nextInt(255); 
               String msg = runtime + ",www.example.com," + ip; 
               KeyedMessage<String, String> data = new KeyedMessage<String, String>("page_visits", ip, msg);
               producer.send(data);
        }
        producer.close();
    }
}

SimplePartitioner.java

package cn.ljh.kafka.kafka_helloworld;

import kafka.producer.Partitioner;
import kafka.utils.VerifiableProperties;
 
public class SimplePartitioner implements Partitioner {
    public SimplePartitioner (VerifiableProperties props) {
 
    }
 
    public int partition(Object key, int a_numPartitions) {
        int partition = 0;
        String stringKey = (String) key;
        int offset = stringKey.lastIndexOf(‘.‘);
        if (offset > 0) {
           partition = Integer.parseInt( stringKey.substring(offset+1)) % a_numPartitions;
        }
       return partition;
  }
 
}

ConsumerGroupExample.java

package cn.ljh.kafka.kafka_helloworld;

import kafka.consumer.ConsumerConfig;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
 

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 java.util.concurrent.TimeUnit;
 
public class ConsumerGroupExample {
    private final ConsumerConnector consumer;
    private final String topic;
    private  ExecutorService executor;
 
    public ConsumerGroupExample(String a_zookeeper, String a_groupId, String a_topic) {
        consumer = kafka.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();
        try {
            if (!executor.awaitTermination(5000, TimeUnit.MILLISECONDS)) {
                System.out.println("Timed out waiting for consumer threads to shut down, exiting uncleanly");
            }
        } catch (InterruptedException e) {
            System.out.println("Interrupted during shutdown, exiting uncleanly");
        }
   }
 
    public void run(int a_numThreads) {
        Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
        topicCountMap.put(topic, new Integer(a_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(a_numThreads);
 
        // now create an object to consume the messages
        //
        int threadNumber = 0;
        for (final KafkaStream stream : streams) {
            executor.submit(new ConsumerTest(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[] args) {
//        String zooKeeper = args[0];
//        String groupId = args[1];
//        String topic = args[2];
//        int threads = Integer.parseInt(args[3]);
        
        String zooKeeper = "192.168.137.176:2181,192.168.137.176:2182,192.168.137.176:2183";
        String groupId = "group1";
        String topic = "page_visits";
        int threads = 5;
 
        ConsumerGroupExample example = new ConsumerGroupExample(zooKeeper, groupId, topic);
        example.run(threads);
 
        try {
            Thread.sleep(10000);
        } catch (InterruptedException ie) {
 
        }
        example.shutdown();
    }
}

ConsumerTest.java

package cn.ljh.kafka.kafka_helloworld;

import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
 
public class ConsumerTest implements Runnable {
    private KafkaStream m_stream;
    private int m_threadNumber;
 
    public ConsumerTest(KafkaStream a_stream, int a_threadNumber) {
        m_threadNumber = a_threadNumber;
        m_stream = a_stream;
    }
 
    public void run() {
        ConsumerIterator<byte[], byte[]> it = m_stream.iterator();
        //线程会一直等待有消息进入
        while (it.hasNext())
            System.out.println("Thread " + m_threadNumber + ": " + new String(it.next().message()));
        System.out.println("Shutting down Thread: " + m_threadNumber);
    }
}