    001    /**
    002     * Licensed to the Apache Software Foundation (ASF) under one
    003     * or more contributor license agreements.  See the NOTICE file
    004     * distributed with this work for additional information
    005     * regarding copyright ownership.  The ASF licenses this file
    006     * to you under the Apache License, Version 2.0 (the
    007     * "License"); you may not use this file except in compliance
    008     * with the License.  You may obtain a copy of the License at
    009     *
    010     *     http://www.apache.org/licenses/LICENSE-2.0
    011     *
    012     * Unless required by applicable law or agreed to in writing, software
    013     * distributed under the License is distributed on an "AS IS" BASIS,
    014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    015     * See the License for the specific language governing permissions and
    016     * limitations under the License.
    017     */
    018
    019    package org.apache.hadoop.mapred;
    020
    021    import java.io.IOException;
    022
    023    import org.apache.hadoop.classification.InterfaceAudience;
    024    import org.apache.hadoop.classification.InterfaceStability;
    025    import org.apache.hadoop.io.Closeable;
    026
    027    /**
    028     * Base class for {@link Mapper} and {@link Reducer} implementations.
    029     *
    030     * <p>Provides default no-op implementations for a few methods, most non-trivial
    031     * applications need to override some of them.</p>
    032     */
    033    @InterfaceAudience.Public
    034    @InterfaceStability.Stable
    035    public class MapReduceBase implements Closeable, JobConfigurable {
    036
    037      /** Default implementation that does nothing. */
    038      public void close() throws IOException {
    039      }
    040
    041      /** Default implementation that does nothing. */
    042      public void configure(JobConf job) {
    043      }
    044
    045    }