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

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Here is the source code for org.springframework.kafka.core.ConsumerFactory.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.core;

import java.util.Map;
import java.util.Properties;

import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.common.serialization.Deserializer;

import org.springframework.lang.Nullable;

/**
 * The strategy to produce a {@link Consumer} instance(s).
 *
 * @param <K> the key type.
 * @param <V> the value type.
 *
 * @author Gary Russell
 * @author Artem Bilan
 */
public interface ConsumerFactory<K, V> {

    /**
     * Create a consumer with the group id and client id as configured in the properties.
     * @return the consumer.
     */
    default Consumer<K, V> createConsumer() {
        return createConsumer(null);
    }

    /**
     * Create a consumer, appending the suffix to the {@code client.id} property,
     * if present.
     * @param clientIdSuffix the suffix.
     * @return the consumer.
     * @since 1.3
     */
    default Consumer<K, V> createConsumer(@Nullable String clientIdSuffix) {
        return createConsumer(null, clientIdSuffix);
    }

    /**
     * Create a consumer with an explicit group id; in addition, the
     * client id suffix is appended to the {@code client.id} property, if both
     * are present.
     * @param groupId the group id.
     * @param clientIdSuffix the suffix.
     * @return the consumer.
     * @since 1.3
     */
    default Consumer<K, V> createConsumer(@Nullable String groupId, @Nullable String clientIdSuffix) {
        return createConsumer(groupId, null, clientIdSuffix);
    }

    /**
     * Create a consumer with an explicit group id; in addition, the
     * client id suffix is appended to the clientIdPrefix which overrides the
     * {@code client.id} property, if present.
     * @param groupId the group id.
     * @param clientIdPrefix the prefix.
     * @param clientIdSuffix the suffix.
     * @return the consumer.
     * @since 2.1.1
     */
    Consumer<K, V> createConsumer(@Nullable String groupId, @Nullable String clientIdPrefix,
            @Nullable String clientIdSuffix);

    /**
     * Create a consumer with an explicit group id; in addition, the
     * client id suffix is appended to the clientIdPrefix which overrides the
     * {@code client.id} property, if present. In addition, consumer properties can
     * be overridden if the factory implementation supports it.
     * @param groupId the group id.
     * @param clientIdPrefix the prefix.
     * @param clientIdSuffix the suffix.
     * @param properties the properties to override.
     * @return the consumer.
     * @since 2.2.4
     */
    default Consumer<K, V> createConsumer(@Nullable String groupId, @Nullable String clientIdPrefix,
            @Nullable String clientIdSuffix, @Nullable Properties properties) {

        return createConsumer(groupId, clientIdPrefix, clientIdSuffix);
    }

    /**
     * Return true if consumers created by this factory use auto commit.
     * @return true if auto commit.
     */
    boolean isAutoCommit();

    /**
     * Return an unmodifiable reference to the configuration map for this factory.
     * Useful for cloning to make a similar factory.
     * @return the configs.
     * @since 2.0
     */
    default Map<String, Object> getConfigurationProperties() {
        throw new UnsupportedOperationException("'getConfigurationProperties()' is not supported");
    }

    /**
     * Return the configured key deserializer (if provided as an object instead
     * of a class name in the properties).
     * @return the deserializer.
     * @since 2.0
     */
    @Nullable
    default Deserializer<K> getKeyDeserializer() {
        return null;
    }

    /**
     * Return the configured value deserializer (if provided as an object instead
     * of a class name in the properties).
     * @return the deserializer.
     * @since 2.0
     */
    @Nullable
    default Deserializer<V> getValueDeserializer() {
        return null;
    }

}