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.kstream;
  
  import org.apache.kafka.streams.processor.api.FixedKeyProcessor;
  
  /**
   * The {@code ValueMapper} interface for mapping a value to a new value of arbitrary type.
   * This is a stateless record-by-record operation, i.e, {@link #apply(Object)} is invoked individually for each record
   * of a stream (cf. {@link org.apache.kafka.streams.processor.api.FixedKeyProcessor} for stateful value transformation).
   * If {@code ValueMapper} is applied to a {@link org.apache.kafka.streams.processor.api.Record} the record's
   * key is preserved.
   * If a record's key and value should be modified {@link KeyValueMapper} can be used.
   *
   * @param <V>  value type
   * @param <VR> mapped value type
   * @see KeyValueMapper
   * @see FixedKeyProcessor
   * @see KStream#mapValues(ValueMapper)
   * @see KStream#mapValues(ValueMapperWithKey)
   * @see KStream#flatMapValues(ValueMapper)
   * @see KStream#flatMapValues(ValueMapperWithKey)
   * @see KTable#mapValues(ValueMapper)
   * @see KTable#mapValues(ValueMapperWithKey)
   */
  @FunctionalInterface
  public interface ValueMapper<V, VR> {
  
      /**
       * Map the given value to a new value.
       *
       * @param value the value to be mapped
       * @return the new value
       */
      VR apply(final V value);
  }
  