hadoop.RegexParserMap.java Source code

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Here is the source code for hadoop.RegexParserMap.java

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/*
 * Copyright (c) 2007-2010 Concurrent, Inc. All Rights Reserved.
 *
 * Project and contact information: http://www.cascading.org/
 *
 * This file is part of the Cascading project.
 *
 * Cascading 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.
 *
 * Cascading 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 Cascading.  If not, see <http://www.gnu.org/licenses/>.
 */

package hadoop;

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.*;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 *
 */
public class RegexParserMap extends MapReduceBase implements Mapper<LongWritable, Text, Text, Text> {
    private Pattern pattern;
    private Matcher matcher;

    @Override
    public void configure(JobConf job) {
        pattern = Pattern.compile(job.get("logparser.regex"));
        matcher = pattern.matcher(""); // lets re-use the matcher
    }

    @Override
    public void map(LongWritable key, Text value, OutputCollector<Text, Text> output, Reporter reporter)
            throws IOException {
        matcher.reset(value.toString());

        if (!matcher.find())
            throw new RuntimeException("could not match pattern: [" + pattern + "] with value: [" + value + "]");

        StringBuffer buffer = new StringBuffer();

        for (int i = 0; i < matcher.groupCount(); i++) {
            if (i != 0)
                buffer.append("\t");

            buffer.append(matcher.group(i + 1)); // skip group 0
        }

        // pass null so a TAB is not prepended, not all OutputFormats accept null
        output.collect(null, new Text(buffer.toString()));
    }
}