edu.umd.cloud9.collection.spinn3r.DemoCountSpinn3rEnglishPosts.java Source code

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Here is the source code for edu.umd.cloud9.collection.spinn3r.DemoCountSpinn3rEnglishPosts.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.spinn3r;

import java.io.IOException;

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.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
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.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.log4j.Logger;

public class DemoCountSpinn3rEnglishPosts extends Configured implements Tool {

    private static final Logger sLogger = Logger.getLogger(DemoCountSpinn3rEnglishPosts.class);

    private static enum Languages {
        TOTAL, EN
    };

    private static class MyMapper extends MapReduceBase
            implements Mapper<LongWritable, Spinn3rItem, LongWritable, Text> {
        public void map(LongWritable key, Spinn3rItem item, OutputCollector<LongWritable, Text> output,
                Reporter reporter) throws IOException {

            if (item.getLanguage().equals("en")) {
                reporter.incrCounter(Languages.EN, 1);
            }
            reporter.incrCounter(Languages.TOTAL, 1);

        }
    }

    /**
     * Creates an instance of this tool.
     */
    public DemoCountSpinn3rEnglishPosts() {
    }

    private static int printUsage() {
        System.out.println("usage: [input] [output-dir]");
        ToolRunner.printGenericCommandUsage(System.out);
        return -1;
    }

    /**
     * Runs this tool.
     */
    public int run(String[] args) throws Exception {
        if (args.length != 2) {
            printUsage();
            return -1;
        }

        String inputPath = args[0];
        String outputPath = args[1];

        sLogger.info("input dir: " + inputPath);
        sLogger.info("output dir: " + outputPath);

        JobConf conf = new JobConf(DemoCountSpinn3rEnglishPosts.class);
        conf.setJobName("DemoCountSpinn3rEnglishPosts");

        conf.setNumReduceTasks(0);

        FileInputFormat.setInputPaths(conf, new Path(inputPath));
        FileOutputFormat.setOutputPath(conf, new Path(outputPath));
        FileOutputFormat.setCompressOutput(conf, false);

        conf.setInputFormat(Spinn3rItemInputFormat.class);
        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(IntWritable.class);

        conf.setMapperClass(MyMapper.class);

        // delete the output directory if it exists already
        FileSystem.get(conf).delete(new Path(outputPath), true);

        JobClient.runJob(conf);

        // clean up
        FileSystem.get(conf).delete(new Path(outputPath), true);

        return 0;
    }

    /**
     * Dispatches command-line arguments to the tool via the
     * <code>ToolRunner</code>.
     */
    public static void main(String[] args) throws Exception {
        int res = ToolRunner.run(new Configuration(), new DemoCountSpinn3rEnglishPosts(), args);
        System.exit(res);
    }
}