GetUserInfoGivenMovieId.java Source code

Introduction

Here is the source code for GetUserInfoGivenMovieId.java

Source

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
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.filecache.DistributedCache;
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;

/*
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/**
 *
 * @author bhumikasaivamani
 */
public class GetUserInfoGivenMovieId {
    public static class Map extends Mapper<LongWritable, Text, Text, Text> {
        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String line = value.toString();
            String[] tokenizedLine = line.split("::");
            String userId = tokenizedLine[0];
            String movieId = tokenizedLine[1];
            String rating = tokenizedLine[2];

            Configuration conf = context.getConfiguration();
            String givenMovieId = conf.get("movieId");

            int checkRating = Integer.parseInt(rating);
            if (movieId.equals(givenMovieId)) {
                if (checkRating >= 4) {
                    context.write(new Text(userId), new Text(rating));
                }
            }

        }
    }

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

        public void reduce(Text key, Text values, Context context) throws IOException, InterruptedException {
            context.write(key, values);
        }
    }

    public static class MapWithJoin extends Mapper<LongWritable, Text, Text, Text> {

        private java.util.Map<String, String> userInfo = new HashMap<String, String>();
        File F;

        @Override
        public void setup(Context context) throws IOException, InterruptedException {

            //Configuration conf = context.getConfiguration();
            //Path[] p = DistributedCache.getLocalCacheFiles(conf);
            Path[] files = DistributedCache.getLocalCacheFiles(context.getConfiguration());

            F = new File(files[0].getName().toString());
            /*//Path[] cacheFiles = context.getLocalCacheFiles();
            //F=new File(cacheFiles[0].toString());
            //FileInputStream fileStream = new FileInputStream(cacheFiles[0].toString());
             Path[] cacheFiles =DistributedCache.getLocalCacheFiles(context.getConfiguration());*/
            BufferedReader br = new BufferedReader(new FileReader(F));
            String line = br.readLine();

            while ((line = br.readLine()) != null) {
                String[] token = line.split("::");

                userInfo.put(token[0], token[1] + "\t" + token[2]);
            }
        }

        @Override
        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {

            String line = value.toString();
            String[] tokens = line.split("\t");
            String userId = tokens[0];
            String rating = tokens[1];

            if (userInfo.get(userId) != null) {
                context.write(new Text(userId), new Text(userInfo.get(userId)));
            }

        }
    }

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

        public void reduce(Text key, Text values, Context context) throws IOException, InterruptedException {
            context.write(key, values);
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        conf.set("movieId", args[2]);
        Job job = new Job(conf, "GetUserInfoGivenMovieId");

        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);

        job.setJarByClass(GetUserInfoGivenMovieId.class);
        job.setMapperClass(Map.class);
        job.setCombinerClass(Reduce.class);
        job.setReducerClass(Reduce.class);

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[3]));

        boolean flag1 = job.waitForCompletion(true);

        if (flag1) {
            Configuration conf2 = new Configuration();
            //FileSystem fs = FileSystem.get(conf2);
            //Path Intermediate = new Path(args[1]);
            //DistributedCache.addCacheFile(Intermediate.toUri(), conf2);
            //DistributedCache.addCacheFile(new URI(args[1]),conf2);

            Job job2 = new Job(conf2, "UserInfo");
            /*Job job2 = new Job(new Configuration());
            Configuration conf2 = job.getConfiguration();
            job2.setJobName("Join with Cache");
            DistributedCache.addCacheFile(new URI(args[1]), conf2);*/
            job2.addCacheFile(new URI(args[1]));
            job2.setOutputKeyClass(Text.class);
            job2.setOutputValueClass(Text.class);
            job2.setJarByClass(GetUserInfoGivenMovieId.class);
            job2.setMapperClass(MapWithJoin.class);
            //job2.setCombinerClass(Reduce.class);
            job2.setReducerClass(ReduceFinal.class);

            job2.setInputFormatClass(TextInputFormat.class);
            job2.setOutputFormatClass(TextOutputFormat.class);

            FileInputFormat.addInputPath(job2, new Path(args[3]));
            FileOutputFormat.setOutputPath(job2, new Path(args[4]));
            job2.waitForCompletion(true);
        }
    }

}