| /** |
| * 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.mapred; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| import java.util.StringTokenizer; |
| |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.IntWritable; |
| import org.apache.hadoop.io.LongWritable; |
| import org.apache.hadoop.io.Text; |
| |
| public class CombinerJobCreator { |
| |
| public static class MapClass extends MapReduceBase |
| implements Mapper<LongWritable, Text, Text, IntWritable> { |
| |
| private final static IntWritable one = new IntWritable(1); |
| private Text word = new Text(); |
| |
| public void map(LongWritable key, Text value, |
| OutputCollector<Text, IntWritable> output, |
| Reporter reporter) throws IOException { |
| String line = value.toString(); |
| StringTokenizer itr = new StringTokenizer(line); |
| while (itr.hasMoreTokens()) { |
| word.set(itr.nextToken()); |
| output.collect(word, one); |
| } |
| } |
| } |
| |
| public static class Reduce extends MapReduceBase |
| implements Reducer<Text, IntWritable, Text, IntWritable> { |
| |
| public void reduce(Text key, Iterator<IntWritable> values, |
| OutputCollector<Text, IntWritable> output, |
| Reporter reporter) throws IOException { |
| int sum = 0; |
| while (values.hasNext()) { |
| sum += values.next().get(); |
| } |
| output.collect(key, new IntWritable(sum)); |
| } |
| } |
| |
| public static JobConf createJob(String[] args) throws Exception { |
| JobConf conf = new JobConf(CombinerJobCreator.class); |
| conf.setJobName("GridmixCombinerJob"); |
| |
| // the keys are words (strings) |
| conf.setOutputKeyClass(Text.class); |
| // the values are counts (ints) |
| conf.setOutputValueClass(IntWritable.class); |
| |
| conf.setMapperClass(MapClass.class); |
| conf.setCombinerClass(Reduce.class); |
| conf.setReducerClass(Reduce.class); |
| boolean mapoutputCompressed = false; |
| boolean outputCompressed = false; |
| // List<String> other_args = new ArrayList<String>(); |
| for (int i = 0; i < args.length; ++i) { |
| try { |
| if ("-r".equals(args[i])) { |
| conf.setNumReduceTasks(Integer.parseInt(args[++i])); |
| } else if ("-indir".equals(args[i])) { |
| FileInputFormat.setInputPaths(conf, args[++i]); |
| } else if ("-outdir".equals(args[i])) { |
| FileOutputFormat.setOutputPath(conf, new Path(args[++i])); |
| |
| } else if ("-mapoutputCompressed".equals(args[i])) { |
| mapoutputCompressed = Boolean.valueOf(args[++i]).booleanValue(); |
| } else if ("-outputCompressed".equals(args[i])) { |
| outputCompressed = Boolean.valueOf(args[++i]).booleanValue(); |
| } |
| } catch (NumberFormatException except) { |
| System.out.println("ERROR: Integer expected instead of " + args[i]); |
| return null; |
| } catch (ArrayIndexOutOfBoundsException except) { |
| System.out.println("ERROR: Required parameter missing from " |
| + args[i - 1]); |
| return null; |
| } |
| } |
| conf.setCompressMapOutput(mapoutputCompressed); |
| conf.setBoolean("mapred.output.compress", outputCompressed); |
| return conf; |
| } |
| } |