org.sample.hadoop.WordCountV2.java Source code

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Here is the source code for org.sample.hadoop.WordCountV2.java

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/*
 * Copyright (C) 2003-2011 eXo Platform SAS.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see<http://www.gnu.org/licenses/>.
 */
package org.sample.hadoop;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * @author <a href="mailto:haint@exoplatform.com">Nguyen Thanh Hai</a>
 *
 * @datAug 31, 2011
 */
public class WordCountV2 extends Configured implements Tool {
    public static class TokenizerMapper extends Mapper<Object, Text, Text, IntWritable> {
        static enum COUNTERS {
            INPUT_WORDS
        }

        final private static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        private boolean caseSensitive = true;
        private Set<String> patternsToSkip = new HashSet<String>();

        private String inputFile;

        public void setup(Context context) throws IOException, InterruptedException {
            Configuration conf = context.getConfiguration();
            caseSensitive = conf.getBoolean("wordcount.case.sensitive", true);
            String inputFile = conf.get("map.input.file");
            if (conf.getBoolean("wordcount.skip.patterns", false)) {
                Path[] patternsFiles = new Path[0];
                try {
                    patternsFiles = DistributedCache.getLocalCacheArchives(conf);
                } catch (IOException e) {
                    System.err.println(
                            "Caught exception while getting cached files: " + StringUtils.stringifyException(e));
                }
            }
        }

        private void parseSkipFile(Path patternsFile) {
            try {
                BufferedReader fis = new BufferedReader(new FileReader(patternsFile.toString()));
                String pattern = null;
                while ((pattern = fis.readLine()) != null) {
                    patternsToSkip.add(pattern);
                }
            } catch (IOException e) {
                System.err.println(
                        "Caught exception while getting cached files: " + StringUtils.stringifyException(e));
            }
        }

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            String line = (caseSensitive) ? value.toString() : value.toString().toLowerCase();
            for (String pattern : patternsToSkip) {
                line = line.replaceAll(pattern, "");
            }

            StringTokenizer tokenizer = new StringTokenizer(line);
            while (tokenizer.hasMoreTokens()) {
                word.set(tokenizer.nextToken());
                context.write(word, one);
            }
            context.getCounter(COUNTERS.INPUT_WORDS).increment(1);
        }
    }

    public static class IntSumReducer extends Reducer<Text, IntWritable, Text, IntWritable> {

        public void reduce(Text key, Iterable<IntWritable> values, Context context)
                throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable value : values) {
                sum += value.get();
            }
            context.write(key, new IntWritable(sum));
        }
    }

    public int run(String[] args) throws Exception {
        Configuration conf = getConf();
        Job job = new Job(conf);
        job.setJobName("wordcount");
        job.setJarByClass(this.getClass());
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        job.setCombinerClass(IntSumReducer.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TextOutputFormat.class);
        List<String> other_args = new ArrayList<String>();
        for (int i = 0; i < args.length; i++) {
            if ("-skip".equals(args[i])) {
                DistributedCache.addCacheFile(new Path(args[++i]).toUri(), job.getConfiguration());
                job.getConfiguration().setBoolean("wordcount.skip.patterns", true);
            } else {
                other_args.add(args[i]);
            }
        }
        FileInputFormat.addInputPath(job, new Path(other_args.get(0)));
        FileOutputFormat.setOutputPath(job, new Path(other_args.get(1)));
        job.submit();
        return 0;
    }

    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new WordCountV2(), args);
        System.exit(res);
    }
}