JsonTimestampExtractor.java example

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/*
 * 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.examples.pageview;

import com.fasterxml.jackson.databind.JsonNode;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.streams.processor.TimestampExtractor;

/**
 * A timestamp extractor implementation that tries to extract event time from
 * the "timestamp" field in the Json formatted message.
 */
public class JsonTimestampExtractor implements TimestampExtractor {

    @Override
    public long extract(final ConsumerRecord<Object, Object> record, final long previousTimestamp) {
        if (record.value() instanceof PageViewTypedDemo.PageView) {
            return ((PageViewTypedDemo.PageView) record.value()).timestamp;
        }

        if (record.value() instanceof PageViewTypedDemo.UserProfile) {
            return ((PageViewTypedDemo.UserProfile) record.value()).timestamp;
        }

        if (record.value() instanceof JsonNode) {
            return ((JsonNode) record.value()).get("timestamp").longValue();
        }

        throw new IllegalArgumentException("JsonTimestampExtractor cannot recognize the record value " + record.value());
    }
}