org.springframework.kafka.annotation.KafkaStreamsDefaultConfiguration Maven / Gradle / Ivy
/*
* Copyright 2017 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
*
* 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.springframework.kafka.annotation;
import org.apache.kafka.streams.StreamsConfig;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.UnsatisfiedDependencyException;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.core.KStreamBuilderFactoryBean;
/**
* {@code @Configuration} class that registers a {@link KStreamBuilderFactoryBean}
* if {@link StreamsConfig} with the name
* {@link KafkaStreamsDefaultConfiguration#DEFAULT_STREAMS_CONFIG_BEAN_NAME} is present
* in the application context. Otherwise a {@link UnsatisfiedDependencyException} is thrown.
*
* This configuration class is automatically imported when using the @{@link EnableKafkaStreams}
* annotation. See {@link EnableKafkaStreams} Javadoc for complete usage.
*
* @author Artem Bilan
*
* @since 1.1.4
*/
@Configuration
public class KafkaStreamsDefaultConfiguration {
/**
* The bean name for the {@link StreamsConfig} to be used for the default
* {@link KStreamBuilderFactoryBean} bean definition.
*/
public static final String DEFAULT_STREAMS_CONFIG_BEAN_NAME = "defaultKafkaStreamsConfig";
/**
* The bean name for auto-configured default {@link KStreamBuilderFactoryBean}.
*/
public static final String DEFAULT_KSTREAM_BUILDER_BEAN_NAME = "defaultKStreamBuilder";
@Bean(name = DEFAULT_KSTREAM_BUILDER_BEAN_NAME)
public KStreamBuilderFactoryBean defaultKStreamBuilder(
@Qualifier(DEFAULT_STREAMS_CONFIG_BEAN_NAME) ObjectProvider streamsConfigProvider) {
StreamsConfig streamsConfig = streamsConfigProvider.getIfAvailable();
if (streamsConfig != null) {
return new KStreamBuilderFactoryBean(streamsConfig);
}
else {
throw new UnsatisfiedDependencyException(KafkaStreamsDefaultConfiguration.class.getName(),
DEFAULT_KSTREAM_BUILDER_BEAN_NAME, "streamsConfig", "There is no '" +
DEFAULT_STREAMS_CONFIG_BEAN_NAME + "' StreamsConfig bean in the application context.\n" +
"Consider to declare one or don't use @EnableKafkaStreams.");
}
}
}