edu.isi.mavuno.score.CombineScores.java Source code

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Here is the source code for edu.isi.mavuno.score.CombineScores.java

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/*
 * Mavuno: A Hadoop-Based Text Mining Toolkit
 * 
 * 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.
 */

package edu.isi.mavuno.score;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.DoubleWritable;
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.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.log4j.Logger;

import edu.isi.mavuno.util.MavunoUtils;

/**
 * @author metzler
 *
 */
public class CombineScores extends Configured implements Tool {
    private static final Logger sLogger = Logger.getLogger(CombineScores.class);

    public CombineScores(Configuration conf) {
        super(conf);
    }

    private static class MyMapper extends Mapper<LongWritable, Text, Text, DoubleWritable> {

        private final Text mKey = new Text();
        private final DoubleWritable mValue = new DoubleWritable();

        private final StringBuffer mBuffer = new StringBuffer();

        @Override
        public void map(LongWritable key, Text value,
                Mapper<LongWritable, Text, Text, DoubleWritable>.Context context)
                throws IOException, InterruptedException {
            String[] cols = value.toString().split("\t");

            mBuffer.setLength(0);
            for (int i = 0; i < cols.length - 1; i++) {
                mBuffer.append(cols[i]);
                if (i != cols.length - 2) {
                    mBuffer.append('\t');
                }
            }

            mKey.set(mBuffer.toString());
            mValue.set(Double.parseDouble(cols[cols.length - 1]));

            context.write(mKey, mValue);
        }

    }

    private static class MyReducer extends Reducer<Text, DoubleWritable, Text, DoubleWritable> {

        private final DoubleWritable mValue = new DoubleWritable();

        @Override
        public void reduce(Text key, Iterable<DoubleWritable> values,
                Reducer<Text, DoubleWritable, Text, DoubleWritable>.Context context)
                throws IOException, InterruptedException {
            double score = 0.0;
            for (DoubleWritable v : values) {
                score += v.get();
            }

            mValue.set(score);
            context.write(key, mValue);
        }

    }

    /* (non-Javadoc)
     * @see org.apache.hadoop.util.Tool#run(java.lang.String[])
     */
    @Override
    public int run(String[] args) throws ClassNotFoundException, InterruptedException, IOException {
        MavunoUtils.readParameters(args, "Mavuno.CombineScores", getConf());
        return run();
    }

    public int run() throws ClassNotFoundException, InterruptedException, IOException {
        Configuration conf = getConf();

        String inputPath = MavunoUtils.getRequiredParam("Mavuno.CombineScores.InputPath", conf);
        String outputPath = MavunoUtils.getRequiredParam("Mavuno.CombineScores.OutputPath", conf);

        sLogger.info("Tool name: CombineScores");
        sLogger.info(" - Input path: " + inputPath);
        sLogger.info(" - Output path: " + outputPath);

        Job job = new Job(conf);
        job.setJobName("CombineScores");

        MavunoUtils.recursivelyAddInputPaths(job, inputPath);
        FileOutputFormat.setOutputPath(job, new Path(outputPath));

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

        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(DoubleWritable.class);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(DoubleWritable.class);

        job.setMapperClass(MyMapper.class);
        job.setReducerClass(MyReducer.class);

        job.waitForCompletion(true);

        return 0;
    }

}