Edge.java Source code

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Here is the source code for Edge.java

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/**
 *  Licensed 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.
 */

import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
//import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
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.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.io.WritableComparable;

public class Edge {

    public static class SplitMapper extends Mapper<Object, Text, Text, Text> {

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

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {

            String[] l = value.toString().split("[^0-9]");
            word.set(l[0]);
            v.set(l[1]);
            context.write(word, v);

            /*
            for(String line: l){
               if(!line.isEmpty()){
                  line = line.toLowerCase();
                  if(line.equals("harry")||line.equals("hermione")){
                         
                     word.set(line);
                     context.write(word, one);
                  }
                      
               }
                   
                   
            }
            */
            /*
             StringTokenizer itr = new StringTokenizer(value.toString(),"[^a-zA-Z]");
             while (itr.hasMoreTokens()) {
             String s = itr.nextToken();
             s=s.toLowerCase();
             if(s.equals("harry")||s.equals("hermione")){
                word.set(s);
             }
                 
               //word.set(itr.nextToken());
                   
             }
            */

        }
    }

    public static class DuplicateCombiner extends Reducer<Text, Text, Text, Text> {
        private Text v = new Text();

        public void reduce(Text key, Iterable<Text> values, Context context)
                throws IOException, InterruptedException {

            HashSet<String> hs = new HashSet<String>();
            for (Text t : values) {
                if (!hs.contains(t.toString())) {
                    hs.add(t.toString());
                }
                //context.write(key,t);
            }

            Iterator<String> itr = hs.iterator();
            while (itr.hasNext()) {
                v.set(itr.next());
                context.write(key, v);
            }

        }
    }

    public static class IntSumReducer extends Reducer<Text, Text, Text, Text> {
        private Text result = new Text();

        public void reduce(Text key, Iterable<Text> values, Context context)
                throws IOException, InterruptedException {

            HashSet<String> hs = new HashSet<String>();
            for (Text t : values) {
                if (!hs.contains(t.toString())) {
                    hs.add(t.toString());
                }

                //context.write(key,t);
            }

            result.set(String.format("%02d", hs.size()));
            context.write(key, result);

        }
    }

    public static class SwitchMapper extends Mapper<Object, Text, Text, Text> {
        private Text word = new Text();
        private Text v = new Text();

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {

            String[] l = value.toString().split("[^0-9]");
            word.set(l[0]);
            v.set(l[1]);
            context.write(v, word);
        }

    }

    public static class SwitchReducer extends Reducer<Text, Text, Text, Text> {

        public void reduce(Text key, Iterable<Text> values, Context context)
                throws IOException, InterruptedException {
            for (Text t : values) {

                context.write(t, key);

            }
        }
    }

    public static class DecentComparator extends WritableComparator {

        protected DecentComparator() {
            super(Text.class, true);
        }

        @SuppressWarnings("rawtypes")
        @Override
        public int compare(WritableComparable w1, WritableComparable w2) {
            Text t1 = (Text) w1;
            Text t2 = (Text) w2;
            return -t1.compareTo(t2);
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length != 2) {
            System.err.println("Usage: wordcount <in> <out>");
            System.exit(2);
        }

        Path tempDir = new Path("/temp/edge");

        Job job = new Job(conf, "word count");
        job.setJarByClass(Edge.class);

        job.setMapperClass(SplitMapper.class);
        job.setCombinerClass(DuplicateCombiner.class);

        //job.setSortComparatorClass(DecentComparator.class);

        job.setReducerClass(IntSumReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);

        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
        FileOutputFormat.setOutputPath(job, tempDir);

        if (job.waitForCompletion(true)) {

            Job job2 = new Job(conf, "edge");
            job2.setJarByClass(Edge.class);
            job2.setMapperClass(SwitchMapper.class);
            job2.setSortComparatorClass(DecentComparator.class);
            job2.setReducerClass(SwitchReducer.class);
            job2.setOutputKeyClass(Text.class);
            job2.setOutputValueClass(Text.class);
            FileInputFormat.addInputPath(job2, tempDir);
            FileOutputFormat.setOutputPath(job2, new Path(otherArgs[1]));

            System.exit(job2.waitForCompletion(true) ? 0 : 1);
        }

        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}