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.lib; 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.mapred.MapReduceBase; 026 import org.apache.hadoop.mapred.Mapper; 027 import org.apache.hadoop.mapred.OutputCollector; 028 import org.apache.hadoop.mapred.Reporter; 029 030 /** A {@link Mapper} that swaps keys and values. 031 * @deprecated Use {@link org.apache.hadoop.mapreduce.lib.map.InverseMapper} 032 * instead. 033 */ 034 @Deprecated 035 @InterfaceAudience.Public 036 @InterfaceStability.Stable 037 public class InverseMapper<K, V> 038 extends MapReduceBase implements Mapper<K, V, V, K> { 039 040 /** The inverse function. Input keys and values are swapped.*/ 041 public void map(K key, V value, 042 OutputCollector<V, K> output, Reporter reporter) 043 throws IOException { 044 output.collect(value, key); 045 } 046 047 }