org.springframework.kafka.support.converter.BatchMessageConverter.java Source code

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Here is the source code for org.springframework.kafka.support.converter.BatchMessageConverter.java

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/*
 * Copyright 2016-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.kafka.support.converter;

import java.lang.reflect.Type;
import java.util.List;

import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.producer.ProducerRecord;

import org.springframework.kafka.support.Acknowledgment;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;

/**
 * A Kafka-specific {@link Message} converter strategy.
 *
 * @author Gary Russell
 * @since 1.1
 */
public interface BatchMessageConverter extends MessageConverter {

    /**
     * Convert a list of {@link ConsumerRecord} to a {@link Message}.
     * @param records the records.
     * @param acknowledgment the acknowledgment.
     * @param consumer the consumer.
     * @param payloadType the required payload type.
     * @return the message.
     */
    Message<?> toMessage(List<ConsumerRecord<?, ?>> records, Acknowledgment acknowledgment, Consumer<?, ?> consumer,
            Type payloadType);

    /**
     * Convert a message to a producer record.
     * @param message the message.
     * @param defaultTopic the default topic to use if no header found.
     * @return the producer records.
     */
    List<ProducerRecord<?, ?>> fromMessage(Message<?> message, String defaultTopic);

    /**
     * Return the record converter used by this batch converter, if configured,
     * or null.
     * @return the converter or null.
     * @since 2.1.5
     */
    @Nullable
    default RecordMessageConverter getRecordMessageConverter() {
        return null;
    }

}