content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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.apache.kafka.streams;
  
  import org.apache.kafka.clients.admin.Admin;
  import org.apache.kafka.clients.consumer.Consumer;
  import org.apache.kafka.clients.producer.Producer;
  import org.apache.kafka.streams.kstream.GlobalKTable;
  import org.apache.kafka.streams.processor.StateStore;
  
  import java.util.Map;
  
  /**
   * {@code KafkaClientSupplier} can be used to provide custom Kafka clients to a {@link KafkaStreams} instance.
   *
   * @see KafkaStreams#KafkaStreams(Topology, java.util.Properties, KafkaClientSupplier)
   */
  public interface KafkaClientSupplier {
      /**
       * Create an {@link Admin} which is used for internal topic management.
       *
       * @param config Supplied by the {@link java.util.Properties} given to the {@link KafkaStreams}
       * @return an instance of {@link Admin}
       */
      default Admin getAdmin(final Map<String, Object> config) {
          throw new UnsupportedOperationException("Implementations of KafkaClientSupplier should implement the getAdmin() method.");
      }
  
      /**
       * Create a {@link Producer} which is used to write records to sink topics.
       *
       * @param config {@link StreamsConfig#getProducerConfigs(String) producer config} which is supplied by the
       *               {@link java.util.Properties} given to the {@link KafkaStreams} instance
       * @return an instance of Kafka producer
       */
      Producer<byte[], byte[]> getProducer(final Map<String, Object> config);
  
      /**
       * Create a {@link Consumer} which is used to read records of source topics.
       *
       * @param config {@link StreamsConfig#getMainConsumerConfigs(String, String, int) consumer config} which is
       *               supplied by the {@link java.util.Properties} given to the {@link KafkaStreams} instance
       * @return an instance of Kafka consumer
       */
      Consumer<byte[], byte[]> getConsumer(final Map<String, Object> config);
  
      /**
       * Create a {@link Consumer} which is used to read records to restore {@link StateStore}s.
       *
       * @param config {@link StreamsConfig#getRestoreConsumerConfigs(String) restore consumer config} which is supplied
       *               by the {@link java.util.Properties} given to the {@link KafkaStreams}
       * @return an instance of Kafka consumer
       */
      Consumer<byte[], byte[]> getRestoreConsumer(final Map<String, Object> config);
  
      /**
       * Create a {@link Consumer} which is used to consume records for {@link GlobalKTable}.
       *
       * @param config {@link StreamsConfig#getGlobalConsumerConfigs(String) global consumer config} which is supplied
       *               by the {@link java.util.Properties} given to the {@link KafkaStreams}
       * @return an instance of Kafka consumer
       */
      Consumer<byte[], byte[]> getGlobalConsumer(final Map<String, Object> config);
  }
  