edu.isi.mavuno.app.util.ExamplesToSequenceFile.java Source code

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Here is the source code for edu.isi.mavuno.app.util.ExamplesToSequenceFile.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.app.util;

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.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

import edu.isi.mavuno.util.ContextPatternWritable;
import edu.isi.mavuno.util.MavunoUtils;

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

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

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

        private final ContextPatternWritable mContext = new ContextPatternWritable();
        private final DoubleWritable mCount = new DoubleWritable();

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

            mContext.setId(cols[ContextPatternWritable.ID_FIELD]);
            mContext.setContext(cols[ContextPatternWritable.CONTEXT_FIELD]);
            mContext.setPattern(cols[ContextPatternWritable.PATTERN_FIELD]);

            mCount.set(Double.parseDouble(cols[ContextPatternWritable.TOTAL_FIELDS]));

            context.write(mContext, mCount);
        }
    }

    private static class MyReducer
            extends Reducer<ContextPatternWritable, DoubleWritable, ContextPatternWritable, DoubleWritable> {
        /* identity reducer */
    }

    /* (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.ExamplesToSequenceFile", getConf());
        return run();
    }

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

        String contextPath = MavunoUtils.getRequiredParam("Mavuno.ExamplesToSequenceFile.InputPath", conf);
        String outputPath = MavunoUtils.getRequiredParam("Mavuno.ExamplesToSequenceFile.OutputPath", conf);

        sLogger.info("Tool name: ExamplesToSequenceFile");
        sLogger.info(" - Context path: " + contextPath);
        sLogger.info(" - Output path: " + outputPath);

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

        FileInputFormat.addInputPath(job, new Path(contextPath));
        FileOutputFormat.setOutputPath(job, new Path(outputPath));

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

        job.setMapOutputKeyClass(ContextPatternWritable.class);
        job.setSortComparatorClass(ContextPatternWritable.Comparator.class);
        job.setPartitionerClass(ContextPatternWritable.FullPartitioner.class);
        job.setMapOutputValueClass(DoubleWritable.class);

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

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

        job.waitForCompletion(true);
        return 0;
    }

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

}