com.talis.labs.pagerank.mapreduce.UpdatePageRanks.java Source code

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Here is the source code for com.talis.labs.pagerank.mapreduce.UpdatePageRanks.java

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/*
 * Copyright  2011 Talis Systems Ltd.
 *
 * 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.talis.labs.pagerank.mapreduce;

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.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

public class UpdatePageRanks extends Configured implements Tool {

    @Override
    public int run(String[] args) throws Exception {
        if (args.length != 4) {
            System.err.println(
                    "Usage: UpdatePageRanks <input path> <output path> <number of pages> <dangling pages contribution>");
            return -1;
        }

        Configuration conf = getConf();
        conf.set("pagerank.count", args[2]);
        conf.set("pagerank.dangling", args[3]);

        FileSystem.get(conf).delete(new Path(args[1]), true);

        Job job = new Job(conf, "UpdatePageRanks");
        job.setJarByClass(getClass());

        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        job.setMapperClass(UpdatePageRanksMapper.class);
        job.setReducerClass(UpdatePageRanksReducer.class);

        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(Text.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);

        return job.waitForCompletion(true) ? 0 : 1;
    }

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

}