org.springframework.kafka.core.ConsumerFactory Maven / Gradle / Ivy
/*
* Copyright 2016-2020 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.Collections;
import java.util.List;
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 the key type.
* @param the value type.
*
* @author Gary Russell
* @author Artem Bilan
*/
public interface ConsumerFactory {
/**
* Create a consumer with the group id and client id as configured in the properties.
* @return the consumer.
*/
default Consumer 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 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 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 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 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 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 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 getValueDeserializer() {
return null;
}
/**
* Remove a listener.
* @param listener the listener.
* @return true if removed.
* @since 2.5.3
*/
default boolean removeListener(Listener listener) {
return false;
}
/**
* Add a listener at a specific index.
* @param index the index (list position).
* @param listener the listener.
* @since 2.5.3
*/
default void addListener(int index, Listener listener) {
}
/**
* Add a listener.
* @param listener the listener.
* @since 2.5.3
*/
default void addListener(Listener listener) {
}
/**
* Get the current list of listeners.
* @return the listeners.
* @since 2.5.3
*/
default List> getListeners() {
return Collections.emptyList();
}
/**
* Add a post processor.
* @param postProcessor the post processor.
* @since 2.5.3
*/
default void addPostProcessor(ConsumerPostProcessor postProcessor) {
}
/**
* Remove a post processor.
* @param postProcessor the post processor.
* @return true if removed.
* @since 2.5.3
*/
default boolean removePostProcessor(ConsumerPostProcessor postProcessor) {
return false;
}
/**
* Get the current list of post processors.
* @return the post processor.
* @since 2.5.3
*/
default List> getPostProcessors() {
return Collections.emptyList();
}
/**
* Called whenever a consumer is added or removed.
*
* @param the key type.
* @param the value type.
*
* @since 2.5
*
*/
interface Listener {
/**
* A new consumer was created.
* @param id the consumer id (factory bean name and client.id separated by a
* period).
* @param consumer the consumer.
*/
default void consumerAdded(String id, Consumer consumer) {
}
/**
* An existing consumer was removed.
* @param id the consumer id (factory bean name and client.id separated by a
* period).
* @param consumer the consumer.
*/
default void consumerRemoved(String id, Consumer consumer) {
}
}
}