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我正在尝试一个简单的 kafka 生产者消费者客户端 api，我的生产者类工作正常，因为我可以从控制台看到消费者中的消息但是当我运行消费者代码时没有显示任何内容，我不知道问题是什么或我在哪里我做错了

这是生产者代码是 -

package com.app.test;
import java.util.Properties;
import kafka.javaapi.producer.Producer;
import kafka.producer.KeyedMessage;
import kafka.producer.ProducerConfig;

public class SimpleProducer {
    private static Producer<Integer, String> producer;
    private final Properties props = new Properties();public    SimpleProducer()
    {
      props.put("metadata.broker.list", "localhost:9092");
      props.put("serializer.class", "kafka.serializer.StringEncoder");
      props.put("request.required.acks", "1");
      producer = new Producer<Integer, String>(new ProducerConfig(props));
    }
public static void main(String[] args) {
    SimpleProducer sp = new SimpleProducer();
    String topic = "test4";
    String messageStr = "hello";
    KeyedMessage<Integer, String> data = new KeyedMessage<Integer, String>(topic, messageStr);
    System.out.println("producer : "+producer);
    producer.send(data);
    producer.close();
  }
}

消费阶层是——

package com.app.test;

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

public class SimpleHLConsumer {

  private final ConsumerConnector consumer;
  private final String topic;

  public SimpleHLConsumer(String zookeeper, String groupId, String topic) {
      Properties props = new Properties();
    props.put("zookeeper.connect", zookeeper);
    props.put("group.id", groupId);
    props.put("zookeeper.session.timeout.ms", "500");
    props.put("zookeeper.sync.time.ms", "250");
    props.put("auto.commit.interval.ms", "1000");

    consumer = Consumer.createJavaConsumerConnector(
    new ConsumerConfig(props));
    this.topic = topic;
  }



  public void testConsumer() {


    Map<String, Integer> topicCount = new HashMap<String, Integer>();
        // Define single thread for topic
    topicCount.put(topic, new Integer(1));      

    System.out.println("check1");

    Map<String, List<KafkaStream<byte[], byte[]>>> consumerStreams = consumer.createMessageStreams(topicCount);

    System.out.println("check2");
    List<KafkaStream<byte[], byte[]>> streams = consumerStreams.get(topic);

   for (KafkaStream stream : streams) {
        System.out.println("test----");
        System.out.println("test----"+stream.toString());
        ConsumerIterator<byte[], byte[]> consumerIte = stream.iterator();
        while (consumerIte.hasNext()) {
            try {
                System.out.println("Message from Single Topic: " + new String(consumerIte.next().message(), "UTF-8"));
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    if (consumer != null)
      consumer.shutdown();
  }



  public static void main(String[] args) {

    String topic = "test4";
SimpleHLConsumer simpleHLConsumer = new SimpleHLConsumer("localhost:2181", "testgroup", topic);
    simpleHLConsumer.testConsumer();
  }
}

为了检查，我在 testConsumer() 方法中使用 sysout 应用了 2 次检查，所以在运行时只显示 check1 即代码没有到达 check2，我认为有一些问题consumer.createMessageStreams(topicCount);，所以是什么原因以及如何解决它?

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1 回答 1

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代码没有问题。

只需在您的 jar 中构建包含kafka-version（您正在使用的 kafka 版本）的 jar 并运行它并尝试从生产者控制台发送消息。

希望这可以帮助你。

于 2015-03-26T14:53:00.647 回答