Java tutorial
/* * 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 homework.sample; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.NullWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Reducer; import java.io.IOException; /** * Sample Reducer * * @author Edward KIM * @version 0.1 */ public class SampleReducer extends Reducer<Text, Text, NullWritable, Text> { private String outputDelimiter; @Override protected void setup(Context context) throws IOException, InterruptedException { Configuration configuration = context.getConfiguration(); outputDelimiter = configuration.get("outputDelimiter"); } @Override protected void reduce(Text key, Iterable<Text> values, Context context) throws IOException, InterruptedException { context.write(NullWritable.get(), new Text("Hello World")); } @Override protected void cleanup(Context context) throws IOException, InterruptedException { } }