NewConsumer.java

/**
 * Copyright 2016 LinkedIn Corp. Licensed 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.
 */
package com.linkedin.kmf.consumer;

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Properties;

/*
 * Wrap around the new consumer from Apache Kafka and implement the #KMBaseConsumer interface
 */
public class NewConsumer implements KMBaseConsumer {

  private final KafkaConsumer<String, String> _consumer;
  private Iterator<ConsumerRecord<String, String>> _recordIter;

  public NewConsumer(String topic, Properties consumerProperties) {
    _consumer = new KafkaConsumer<>(consumerProperties);
    _consumer.subscribe(Arrays.asList(topic));
  }

  @Override
  public BaseConsumerRecord receive() {
    if (_recordIter == null || !_recordIter.hasNext())
      _recordIter = _consumer.poll(Long.MAX_VALUE).iterator();

    ConsumerRecord<String, String> record = _recordIter.next();
    return new BaseConsumerRecord(record.topic(), record.partition(), record.offset(), record.key(), record.value());
  }

  @Override
  public void close() {
    _consumer.close();
  }

}