/** * 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.hadoop.mapreduce.lib.map; import java.io.IOException; import org.apache.hadoop.mapreduce.Mapper; /** A {@link Mapper} that swaps keys and values. */ public class InverseMapper<K, V> extends Mapper<K,V,V,K> { /** The inverse function. Input keys and values are swapped.*/ @Override public void map(K key, V value, Context context ) throws IOException, InterruptedException { context.write(value, key); } }