trunk/examples/src/main/java/kafka/examples/Consumer.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package kafka.examples;


import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import kafka.consumer.ConsumerConfig;
import kafka.consumer.ConsumerIterator;
import kafka.consumer.KafkaStream;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.message.Message;


public class Consumer extends Thread
{
  private final ConsumerConnector consumer;
  private final String topic;
  
  public Consumer(String topic)
  {
    consumer = kafka.consumer.Consumer.createJavaConsumerConnector(
            createConsumerConfig());
    this.topic = topic;
  }

  private static ConsumerConfig createConsumerConfig()
  {
    Properties props = new Properties();
    props.put("zk.connect", KafkaProperties.zkConnect);
    props.put("groupid", KafkaProperties.groupId);
    props.put("zk.sessiontimeout.ms", "400");
    props.put("zk.synctime.ms", "200");
    props.put("autocommit.interval.ms", "1000");

    return new ConsumerConfig(props);

  }
 
  public void run() {
    Map<String, Integer> topicCountMap = new HashMap<String, Integer>();
    topicCountMap.put(topic, new Integer(1));
    Map<String, List<KafkaStream<Message>>> consumerMap = consumer.createMessageStreams(topicCountMap);
    KafkaStream<Message> stream =  consumerMap.get(topic).get(0);
    ConsumerIterator<Message> it = stream.iterator();
    while(it.hasNext())
      System.out.println(ExampleUtils.getMessage(it.next().message()));
  }
}