nl.basjes.hadoop.io.input.Wordcount.java Source code

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Here is the source code for nl.basjes.hadoop.io.input.Wordcount.java

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/*
 * Apache HTTPD logparsing made easy
 * Copyright (C) 2011-2016 Niels Basjes
 *
 * 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 nl.basjes.hadoop.io.input;

import nl.basjes.hadoop.input.ApacheHttpdLogfileInputFormat;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.MapWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.reduce.LongSumReducer;
import org.apache.hadoop.util.GenericOptionsParser;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import java.io.IOException;
import java.util.List;
import java.util.Map;

public class Wordcount extends Configured implements Tool {

    // ----------------------------------------------------------------------

    private final String logFormat;

    public Wordcount(String logFormat) {
        this.logFormat = logFormat;
    }

    // ----------------------------------------------------------------------

    public static class TokenizerMapper extends Mapper<Object, MapWritable, Text, LongWritable> {

        private static final LongWritable ONE = new LongWritable(1);
        private final Text word = new Text();

        @Override
        public void map(Object key, MapWritable value, Context context) throws IOException, InterruptedException {
            for (Map.Entry<Writable, Writable> entry : value.entrySet()) {
                word.set(entry.getValue().toString());
                context.write(word, ONE);
            }
        }
    }

    // ----------------------------------------------------------------------

    @Override
    public int run(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length != 2) {
            System.err.println("Usage: wordcount <in> <out>");
            return 2;
        }

        conf.set("nl.basjes.parse.apachehttpdlogline.format", logFormat);

        // A ',' separated list of fields
        conf.set("nl.basjes.parse.apachehttpdlogline.fields", "STRING:request.status.last");

        Job job = Job.getInstance(conf, "word count");
        job.setJarByClass(Wordcount.class);
        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));

        job.setInputFormatClass(ApacheHttpdLogfileInputFormat.class);
        job.setMapperClass(TokenizerMapper.class);
        job.setCombinerClass(LongSumReducer.class);
        job.setReducerClass(LongSumReducer.class);

        // configuration should contain reference to your namenode
        FileSystem fs = FileSystem.get(conf);
        // true stands for recursively deleting the folder you gave
        Path outputPath = new Path(otherArgs[1]);
        fs.delete(outputPath, true);
        FileOutputFormat.setOutputPath(job, outputPath);

        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(LongWritable.class);

        if (job.waitForCompletion(true)) {
            return 0;
        }
        return 1;
    }

    // ----------------------------------------------------------------------

    public static void main(String[] args) throws Exception {

        // httpd.conf has this next line:
        //       LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined
        String logFormat = "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"";

        // Developer suggestion:
        // This is what you do to find out what the possible fields are:
        List<String> possibleFields = ApacheHttpdLogfileInputFormat.listPossibleFields(logFormat, null, null);
        System.out.println("----------------------------------------");
        System.out.println("All possible fields are:");
        for (String field : possibleFields) {
            System.out.println(field);
        }
        System.out.println("----------------------------------------");

        System.exit(ToolRunner.run(new Configuration(), new Wordcount(logFormat), args));
    }

    // ----------------------------------------------------------------------

}