de.gesundkrank.wikipedia.hadoop.util.MapFileOutputFormat.java Source code

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Here is the source code for de.gesundkrank.wikipedia.hadoop.util.MapFileOutputFormat.java

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/*
 * This file is part of wikipedia-hadoop.
 * Copyright (C) 2015 Jan Graegger
 *
 * 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see [http://www.gnu.org/licenses/].
 */

package de.gesundkrank.wikipedia.hadoop.util;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.MapFile;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.output.FileOutputCommitter;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;
import java.text.NumberFormat;

public class MapFileOutputFormat extends FileOutputFormat<WritableComparable, Writable> {

    private static final NumberFormat NUMBER_FORMAT = NumberFormat.getInstance();
    static {
        NUMBER_FORMAT.setMinimumIntegerDigits(4);
        NUMBER_FORMAT.setGroupingUsed(false);
    }

    @Override
    public RecordWriter<WritableComparable, Writable> getRecordWriter(TaskAttemptContext context)
            throws IOException, InterruptedException {
        Configuration conf = context.getConfiguration();

        FileOutputCommitter committer = (FileOutputCommitter) getOutputCommitter(context);

        SequenceFile.Writer.Option keyClass = SequenceFile.Writer.keyClass(WritableComparable.class);
        SequenceFile.Writer.Option valueClass = SequenceFile.Writer.valueClass(Writable.class);
        SequenceFile.Writer.Option compressionType = SequenceFile.Writer
                .compression(SequenceFile.CompressionType.BLOCK);

        final MapFile.Writer out = new MapFile.Writer(conf, committer.getWorkPath(), keyClass, valueClass,
                compressionType);

        return new RecordWriter<WritableComparable, Writable>() {
            @Override
            public void close(TaskAttemptContext arg0) throws IOException, InterruptedException {
                out.close();
            }

            @Override
            public void write(WritableComparable key, Writable value) throws IOException, InterruptedException {
                out.append(key, value);
            }
        };
    }
}