KafkaConsumerCallBridge.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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,
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 * See the License for the specific language governing permissions and
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 */

package org.apache.flink.streaming.connectors.kafka.internal;

import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.TopicPartition;

import java.util.List;

/**
 * The ConsumerCallBridge simply calls methods on the {@link KafkaConsumer}.
 * 
 * This indirection is necessary, because Kafka broke binary compatibility between 0.9 and 0.10,
 * for example changing {@code assign(List)} to {@code assign(Collection)}.
 * 
 * Because of that, we need to have two versions whose compiled code goes against different method signatures.
 * Even though the source of subclasses may look identical, the byte code will be different, because they
 * are compiled against different dependencies.
 */
public class KafkaConsumerCallBridge {

	public void assignPartitions(KafkaConsumer<?, ?> consumer, List<TopicPartition> topicPartitions) throws Exception {
		consumer.assign(topicPartitions);
	}

	public void seekPartitionToBeginning(KafkaConsumer<?, ?> consumer, TopicPartition partition) {
		consumer.seekToBeginning(partition);
	}

	public void seekPartitionToEnd(KafkaConsumer<?, ?> consumer, TopicPartition partition) {
		consumer.seekToEnd(partition);
	}

}