streams/src/main/java/org/apache/kafka/streams/processor/ConsumerRecordTimestampExtractor.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 org.apache.kafka.streams.processor;

import org.apache.kafka.clients.consumer.ConsumerRecord;

/**
 * Retrieves built-in timestamps from Kafka messages (introduced in KIP-32: Add timestamps to Kafka message).
 *
 * Here, "built-in" refers to the fact that compatible Kafka producer clients automatically and
 * transparently embed such timestamps into messages they sent to Kafka, which can then be retrieved
 * via this timestamp extractor.
 *
 * If <i>CreateTime</i> is used to define the built-in timestamps, using this extractor effectively provide
 * <i>event-time</i> semantics. If <i>LogAppendTime</i> is used to define the built-in timestamps, using
 * this extractor effectively provides <i>ingestion-time</i> semantics.
 *
 * If you need <i>processing-time</i> semantics, use {@link WallclockTimestampExtractor}.
 */
public class ConsumerRecordTimestampExtractor implements TimestampExtractor {
    @Override
    public long extract(ConsumerRecord<Object, Object> record) {
        return record.timestamp();
    }
}