org.sf.xrime.postprocessing.SequenceFileToTextFileTransformer.java Source code

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Here is the source code for org.sf.xrime.postprocessing.SequenceFileToTextFileTransformer.java

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/*
 * Copyright (C) IBM Corp. 2009.
 * 
 * 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 org.sf.xrime.postprocessing;

import java.io.IOException;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.util.ToolRunner;
import org.sf.xrime.ProcessorExecutionException;
import org.sf.xrime.Transformer;

/**
 * This class is used to transform all graph algorithms' outputs in form of sequence files
 * into text files, which are human-readable.
 */
public class SequenceFileToTextFileTransformer extends Transformer {
    /**
     * Default constructor.
     */
    public SequenceFileToTextFileTransformer() {
        super();
    }

    /**
     * Constructor.
     * @param src
     * @param dest
     */
    public SequenceFileToTextFileTransformer(Path src, Path dest) {
        super(src, dest);
    }

    @Override
    public void execute() throws ProcessorExecutionException {
        JobConf convertor = new JobConf(conf, SequenceFileToTextFileTransformer.class);
        convertor.setJobName("SequenceFileToTextFileTransformer");

        convertor.setInputFormat(SequenceFileInputFormat.class);
        convertor.setOutputFormat(TextOutputFormat.class);

        convertor.setMapperClass(SequenceFileToTextFileMapper.class);
        convertor.setMapOutputValueClass(Text.class);
        convertor.setOutputKeyClass(Text.class);
        convertor.setOutputValueClass(Text.class);

        // ONLY mapper, no combiner, no reducer.
        convertor.setNumMapTasks(getMapperNum());
        convertor.setNumReduceTasks(0);

        FileInputFormat.setInputPaths(convertor, srcPath);
        FileOutputFormat.setOutputPath(convertor, destPath);
        try {
            this.runningJob = JobClient.runJob(convertor);
        } catch (IOException e) {
            throw new ProcessorExecutionException(e);
        }
    }

    public static void main(String[] args) {
        try {
            int res = ToolRunner.run(new SequenceFileToTextFileTransformer(), args);
            System.exit(res);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

}