com.cloudera.seismic.segy.SegyUnloader.java Source code

Introduction

Here is the source code for com.cloudera.seismic.segy.SegyUnloader.java

Source

/**
 * Copyright (c) 2011, Cloudera, Inc. All Rights Reserved.
 *
 * Cloudera, Inc. licenses this file to you 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
 *
 * This software 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 com.cloudera.seismic.segy;

import java.io.DataOutputStream;
import java.io.FileOutputStream;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.PosixParser;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathFilter;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

public class SegyUnloader extends Configured implements Tool {

    private void write(Path path, DataOutputStream out, Configuration conf) throws Exception {
        System.out.println("Reading: " + path);
        SequenceFile.Reader reader = new SequenceFile.Reader(FileSystem.get(conf), path, conf);
        BytesWritable value = new BytesWritable();
        while (reader.next(NullWritable.get(), value)) {
            out.write(value.getBytes(), 0, value.getLength());
        }
        reader.close();
    }

    @Override
    public int run(String[] args) throws Exception {
        Options options = new Options();
        options.addOption("input", true, "SU sequence files to export from Hadoop");
        options.addOption("output", true, "The local SU file to write");

        // Parse the commandline and check for required arguments.
        CommandLine cmdLine = new PosixParser().parse(options, args, false);
        if (!cmdLine.hasOption("input") || !cmdLine.hasOption("output")) {
            System.out.println("Mising required input/output arguments");
            new HelpFormatter().printHelp("SegyUnloader", options);
            System.exit(1);
        }

        Configuration conf = getConf();
        FileSystem hdfs = FileSystem.get(conf);
        Path inputPath = new Path(cmdLine.getOptionValue("input"));
        if (!hdfs.exists(inputPath)) {
            System.out.println("Input path does not exist");
            System.exit(1);
        }

        PathFilter pf = new PathFilter() {
            @Override
            public boolean accept(Path path) {
                return !path.getName().startsWith("_");
            }
        };

        DataOutputStream os = new DataOutputStream(new FileOutputStream(cmdLine.getOptionValue("output")));
        for (FileStatus fs : hdfs.listStatus(inputPath, pf)) {
            write(fs.getPath(), os, conf);
        }
        os.close();

        return 0;
    }

    public static void main(String[] args) throws Exception {
        ToolRunner.run(new SegyUnloader(), args);
    }
}