com.mh2c.WikipediaWordCountDriver.java Source code

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Here is the source code for com.mh2c.WikipediaWordCountDriver.java

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/*
Copyright 2016 William A. Havanki, Jr.
    
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 com.mh2c;

import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.SequenceFileInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

/**
 * Reads sequence files of Wikipedia text and counts words in them.
 */
public class WikipediaWordCountDriver extends Configured implements Tool {

    @Override
    public int run(String[] args) throws Exception {
        // arg checks

        JobConf conf = new JobConf(getClass());
        conf.setJobName("WP word count");

        // Set the mapper and reducer classes, and use the reducer as a combiner
        conf.setMapperClass(WikipediaWordCountMapper.class);
        conf.setReducerClass(WikipediaWordCountReducer.class);
        conf.setCombinerClass(WikipediaWordCountReducer.class);
        // The object key/value pairs are text words and integer counts
        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(IntWritable.class);

        // Read in sequence files
        conf.setInputFormat(SequenceFileInputFormat.class);
        SequenceFileInputFormat.addInputPath(conf, new Path(args[0]));
        // Emit ordinary text files
        conf.setOutputFormat(TextOutputFormat.class);
        TextOutputFormat.setOutputPath(conf, new Path(args[1]));

        JobClient.runJob(conf);
        return 0;
    }

    public static void main(String[] args) throws Exception {
        int exitCode = ToolRunner.run(new WikipediaWordCountDriver(), args);
        System.exit(exitCode);
    }
}