edu.cuhk.hccl.SequenceFileWriter.java Source code

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Here is the source code for edu.cuhk.hccl.SequenceFileWriter.java

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/**
 * Copyright (C) 2014 Pengfei Liu <pfliu@se.cuhk.edu.hk>
 * The Chinese University of Hong Kong.
 *
 * This file is part of aspect-opinion.
 *
 * 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.cuhk.hccl;

import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.Arrays;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;

public class SequenceFileWriter {

    public static void main(String[] args) throws IOException {
        // Check parameters
        if (args.length < 3) {
            System.out.print("Please specify three parameters!");
            System.exit(-1);
        }

        File filesDir = new File(args[0]);
        String targetDir = args[1];
        final int NUM_SPLITS = Integer.parseInt(args[2]);

        // Remove old target directory first
        FileUtils.deleteQuietly(new File(targetDir));

        File[] dataFiles = filesDir.listFiles();

        int total = dataFiles.length;
        int range = (int) Math.round(total / NUM_SPLITS + 0.5);
        System.out.printf("[INFO] The number of total files is %d \n.", total);

        for (int i = 1; i <= NUM_SPLITS; i++) {
            int start = (i - 1) * range;
            int end = Math.min(start + range, total);
            File[] subFiles = Arrays.copyOfRange(dataFiles, start, end);
            createSeqFile(subFiles, FilenameUtils.normalize(targetDir + "/" + i + ".seq"));
        }

        System.out.println("[INFO] All files have been successfully processed!");
    }

    private static void createSeqFile(File[] files, String seqName) {
        Configuration conf = new Configuration();
        LongWritable key = new LongWritable();
        Text value = new Text();

        SequenceFile.Writer writer = null;

        try {
            FileSystem fs = FileSystem.get(URI.create(seqName), conf);
            writer = SequenceFile.createWriter(fs, conf, new Path(seqName), key.getClass(), value.getClass());

            for (File file : files) {
                //System.out.printf("Processing file: %s \n", file.getPath());
                key.set(Integer.parseInt(file.getName().split("_")[1]));
                value.set(FileUtils.readFileToString(file));
                writer.append(key, value);
            }
            System.out.printf("[INFO] The sequence file %s has been created for %d files! \n", seqName,
                    files.length);

        } catch (IOException e) {
            System.out.println(e.getMessage());
        } finally {
            IOUtils.closeStream(writer);
        }
    }
}