edu.umd.cloud9.collection.wikipedia.DemoCountWikipediaPages.java Source code

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Here is the source code for edu.umd.cloud9.collection.wikipedia.DemoCountWikipediaPages.java

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/*
 * Cloud9: A MapReduce Library for Hadoop
 *
 * 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.umd.cloud9.collection.wikipedia;

import java.io.IOException;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.lib.NullOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

/**
 * Tool for counting the number of pages in a particular Wikipedia XML dump file. This program keeps
 * track of total number of pages, redirect pages, disambiguation pages, empty pages, actual
 * articles (including stubs), stubs, and non-articles ("File:", "Category:", "Wikipedia:", etc.).
 * This also provides a skeleton for MapReduce programs to process the collection. Specify input
 * path to the Wikipedia XML dump file with the {@code -input} flag.
 *
 * @author Jimmy Lin
 */
@SuppressWarnings("deprecation")
public class DemoCountWikipediaPages extends Configured implements Tool {
    private static final Logger LOG = Logger.getLogger(DemoCountWikipediaPages.class);

    private static enum PageTypes {
        TOTAL, REDIRECT, DISAMBIGUATION, EMPTY, ARTICLE, STUB, NON_ARTICLE
    };

    private static class MyMapper extends MapReduceBase
            implements Mapper<LongWritable, WikipediaPage, Text, IntWritable> {

        public void map(LongWritable key, WikipediaPage p, OutputCollector<Text, IntWritable> output,
                Reporter reporter) throws IOException {
            reporter.incrCounter(PageTypes.TOTAL, 1);

            if (p.isRedirect()) {
                reporter.incrCounter(PageTypes.REDIRECT, 1);

            } else if (p.isDisambiguation()) {
                reporter.incrCounter(PageTypes.DISAMBIGUATION, 1);
            } else if (p.isEmpty()) {
                reporter.incrCounter(PageTypes.EMPTY, 1);
            } else if (p.isArticle()) {
                reporter.incrCounter(PageTypes.ARTICLE, 1);

                if (p.isStub()) {
                    reporter.incrCounter(PageTypes.STUB, 1);
                }
            } else {
                reporter.incrCounter(PageTypes.NON_ARTICLE, 1);
            }
        }
    }

    private static final String INPUT_OPTION = "input";

    @SuppressWarnings("static-access")
    @Override
    public int run(String[] args) throws Exception {
        Options options = new Options();
        options.addOption(
                OptionBuilder.withArgName("path").hasArg().withDescription("XML dump file").create(INPUT_OPTION));

        CommandLine cmdline;
        CommandLineParser parser = new GnuParser();
        try {
            cmdline = parser.parse(options, args);
        } catch (ParseException exp) {
            System.err.println("Error parsing command line: " + exp.getMessage());
            return -1;
        }

        if (!cmdline.hasOption(INPUT_OPTION)) {
            HelpFormatter formatter = new HelpFormatter();
            formatter.printHelp(this.getClass().getName(), options);
            ToolRunner.printGenericCommandUsage(System.out);
            return -1;
        }

        String inputPath = cmdline.getOptionValue(INPUT_OPTION);

        LOG.info("Tool name: " + this.getClass().getName());
        LOG.info(" - XML dump file: " + inputPath);

        JobConf conf = new JobConf(getConf(), DemoCountWikipediaPages.class);
        conf.setJobName(String.format("DemoCountWikipediaPages[%s: %s]", INPUT_OPTION, inputPath));

        conf.setNumMapTasks(10);
        conf.setNumReduceTasks(0);

        FileInputFormat.setInputPaths(conf, new Path(inputPath));

        conf.setInputFormat(WikipediaPageInputFormat.class);
        conf.setOutputFormat(NullOutputFormat.class);

        conf.setMapperClass(MyMapper.class);

        JobClient.runJob(conf);

        return 0;
    }

    public DemoCountWikipediaPages() {
    }

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