name.abhijitsarkar.hadoop.join.ReduceSideJoinDriver.java Source code

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Here is the source code for name.abhijitsarkar.hadoop.join.ReduceSideJoinDriver.java

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/*******************************************************************************
 * Copyright (c) 2014, the original author or authors.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * 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.
 *
 * A copy of the GNU General Public License accompanies this software, 
 * and is also available at http://www.gnu.org/licenses.
 *******************************************************************************/
package name.abhijitsarkar.hadoop.join;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
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.lib.input.MultipleInputs;
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.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * @author Abhijit Sarkar
 */
public class ReduceSideJoinDriver extends Configured implements Tool {
    @Override
    public int run(String[] args) throws Exception {
        Configuration conf = getConf();
        Job job = new Job(conf, "reduce-side-join");
        job.setJarByClass(getClass());

        job.setPartitionerClass(KeyPartitioner.class);
        job.setGroupingComparatorClass(KeyGroupingComparator.class);

        job.setReducerClass(ReduceSideJoinReducer.class);

        job.setOutputKeyClass(IntWritable.class);
        job.setOutputValueClass(Text.class);
        job.setOutputFormatClass(TextOutputFormat.class);

        MultipleInputs.addInputPath(job, new Path(args[0], "customers.txt"), TextInputFormat.class,
                CustomerMapper.class);
        MultipleInputs.addInputPath(job, new Path(args[0], "orders.txt"), TextInputFormat.class, OrderMapper.class);

        job.setMapOutputKeyClass(TaggedKey.class);
        job.setMapOutputValueClass(Text.class);
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

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

    public static void main(String[] args) throws Exception {
        // TODO: Get rid of the GenericOptionsParser and just pass the args to the ToolRunner
        GenericOptionsParser parser = new GenericOptionsParser(new Configuration(), args);

        if (parser.getRemainingArgs().length < 2) {
            throw new IllegalArgumentException("Not enough arguments.");
        }

        ToolRunner.run(new ReduceSideJoinDriver(), parser.getRemainingArgs());
    }
}