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

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Here is the source code for edu.isi.mavuno.app.util.SequenceFileToText.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.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat;
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.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

import edu.isi.mavuno.util.MavunoUtils;

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

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

    private static class MyMapper extends Mapper<Writable, Writable, Text, Text> {

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

        @Override
        public void map(Writable key, Writable value, Mapper<Writable, Writable, Text, Text>.Context context)
                throws IOException, InterruptedException {
            mKey.set(key.toString());
            mValue.set(value.toString());
            context.write(mKey, 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.SequenceFileToText", getConf());
        return run();
    }

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

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

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

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

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

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

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

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

        job.setMapperClass(MyMapper.class);
        job.setNumReduceTasks(0);

        job.waitForCompletion(true);
        return 0;
    }

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

}