org.springframework.kafka.core.ProducerFactoryUtils.java Source code

Introduction

Here is the source code for org.springframework.kafka.core.ProducerFactoryUtils.java

Source

/*
 * Copyright 2002-2019 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.core;

import org.apache.kafka.clients.producer.Producer;

import org.springframework.kafka.support.KafkaUtils;
import org.springframework.lang.Nullable;
import org.springframework.transaction.support.ResourceHolderSynchronization;
import org.springframework.transaction.support.TransactionSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.util.Assert;

/**
 * Helper class for managing a Spring based Kafka {@link DefaultKafkaProducerFactory}
 * in particular for obtaining transactional Kafka resources for a given ProducerFactory.
 *
 * <p>
 * Mainly for internal use within the framework.
 *
 * @author Gary Russell
 */
public final class ProducerFactoryUtils {

    private ProducerFactoryUtils() {
        super();
    }

    /**
     * Obtain a Producer that is synchronized with the current transaction, if any.
     * @param producerFactory the ProducerFactory to obtain a Channel for
     * @param <K> the key type.
     * @param <V> the value type.
     * @return the resource holder.
     */
    public static <K, V> KafkaResourceHolder<K, V> getTransactionalResourceHolder(
            final ProducerFactory<K, V> producerFactory) {

        return getTransactionalResourceHolder(producerFactory, null);
    }

    /**
     * Obtain a Producer that is synchronized with the current transaction, if any.
     * @param producerFactory the ProducerFactory to obtain a Channel for
     * @param txIdPrefix the transaction id prefix; if null, the producer factory
     * prefix is used.
     * @param <K> the key type.
     * @param <V> the value type.
     * @return the resource holder.
     * @since 2.3
     */
    public static <K, V> KafkaResourceHolder<K, V> getTransactionalResourceHolder(
            final ProducerFactory<K, V> producerFactory, @Nullable String txIdPrefix) {

        Assert.notNull(producerFactory, "ProducerFactory must not be null");

        @SuppressWarnings("unchecked")
        KafkaResourceHolder<K, V> resourceHolder = (KafkaResourceHolder<K, V>) TransactionSynchronizationManager
                .getResource(producerFactory);
        if (resourceHolder == null) {
            Producer<K, V> producer = producerFactory.createProducer(txIdPrefix);

            try {
                producer.beginTransaction();
            } catch (RuntimeException e) {
                producer.close();
                throw e;
            }

            resourceHolder = new KafkaResourceHolder<K, V>(producer);
            bindResourceToTransaction(resourceHolder, producerFactory);
        }
        return resourceHolder;
    }

    public static <K, V> void releaseResources(@Nullable KafkaResourceHolder<K, V> resourceHolder) {
        if (resourceHolder != null) {
            resourceHolder.getProducer().close();
        }
    }

    /**
     * Set the group id for the consumer bound to this thread.
     * @param groupId the group id.
     * @deprecated in favor of {@link KafkaUtils#setConsumerGroupId(String)}.
     * @since 1.3
     */
    @Deprecated
    public static void setConsumerGroupId(String groupId) {
        KafkaUtils.setConsumerGroupId(groupId);
    }

    /**
     * Get the group id for the consumer bound to this thread.
     * @return the group id.
     * @deprecated in favor of {@link KafkaUtils#getConsumerGroupId()}.
     * @since 1.3
     */
    @Deprecated
    public static String getConsumerGroupId() {
        return KafkaUtils.getConsumerGroupId();
    }

    /**
     * Clear the group id for the consumer bound to this thread.
     * @deprecated in favor of {@link KafkaUtils#clearConsumerGroupId()}.
     * @since 1.3
     */
    @Deprecated
    public static void clearConsumerGroupId() {
        KafkaUtils.clearConsumerGroupId();
    }

    private static <K, V> void bindResourceToTransaction(KafkaResourceHolder<K, V> resourceHolder,
            ProducerFactory<K, V> producerFactory) {
        TransactionSynchronizationManager.bindResource(producerFactory, resourceHolder);
        resourceHolder.setSynchronizedWithTransaction(true);
        if (TransactionSynchronizationManager.isSynchronizationActive()) {
            TransactionSynchronizationManager.registerSynchronization(
                    new KafkaResourceSynchronization<K, V>(resourceHolder, producerFactory));
        }
    }

    /**
     * Callback for resource cleanup at the end of a non-native Kafka transaction (e.g. when participating in a
     * JtaTransactionManager transaction).
     * @see org.springframework.transaction.jta.JtaTransactionManager
     */
    private static final class KafkaResourceSynchronization<K, V>
            extends ResourceHolderSynchronization<KafkaResourceHolder<K, V>, Object> {

        private final KafkaResourceHolder<K, V> resourceHolder;

        KafkaResourceSynchronization(KafkaResourceHolder<K, V> resourceHolder, Object resourceKey) {
            super(resourceHolder, resourceKey);
            this.resourceHolder = resourceHolder;
        }

        @Override
        protected boolean shouldReleaseBeforeCompletion() {
            return false;
        }

        @Override
        public void afterCompletion(int status) {
            try {
                if (status == TransactionSynchronization.STATUS_COMMITTED) {
                    this.resourceHolder.commit();
                } else {
                    this.resourceHolder.rollback();
                }
            } finally {
                super.afterCompletion(status);
            }
        }

        @Override
        protected void releaseResource(KafkaResourceHolder<K, V> holder, Object resourceKey) {
            ProducerFactoryUtils.releaseResources(holder);
        }

    }

}