pulsar-io/kafka/src/main/java/org/apache/pulsar/io/kafka/KafkaBytesSink.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.pulsar.io.kafka;

import java.util.Properties;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.ByteArraySerializer;
import org.apache.kafka.common.serialization.StringSerializer;
import org.apache.pulsar.functions.api.Record;
import org.apache.pulsar.io.core.KeyValue;
import org.apache.pulsar.io.core.annotations.Connector;
import org.apache.pulsar.io.core.annotations.IOType;

/**
 * Kafka sink should treats incoming messages as pure bytes. So we don't
 * apply schema into it.
 */
@Connector(
    name = "kafka",
    type = IOType.SINK,
    help = "The KafkaBytesSink is used for moving messages from Pulsar to Kafka.",
    configClass = KafkaSinkConfig.class
)
@Slf4j
public class KafkaBytesSink extends KafkaAbstractSink<String, byte[]> {

    @Override
    protected Properties beforeCreateProducer(Properties props) {
        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class.getName());
        log.info("Created kafka producer config : {}", props);
        return props;
    }

    @Override
    public KeyValue<String, byte[]> extractKeyValue(Record<byte[]> record) {
        return new KeyValue<>(record.getKey().orElse(null), record.getValue());
    }
}