nl.utwente.bigdata.MapReduce4v1.java Source code

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Here is the source code for nl.utwente.bigdata.MapReduce4v1.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.utwente.bigdata;

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

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import org.json.simple.parser.JSONParser;

/**
 * @author Adrechsel
 *
 */
public class MapReduce4v1 {

    public static class LanguageMapper extends Mapper<Object, Text, Text, Text> {

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            String[] splitValue = value.toString().split("\\s");
            context.write(new Text(
                    context.getConfiguration().get("newLang") + "\t" + splitValue[1] + "\t" + splitValue[2]),
                    new Text(splitValue[3]));
        }
    }

    public static class LanguageReducer extends Reducer<Text, Text, Text, Text> {

        public void reduce(Text key, Iterable<Text> values, Context context)
                throws IOException, InterruptedException {
            int counter = 0;
            for (Text value : values) {
                counter = counter + (Integer.parseInt(value.toString()));
            }
            context.write(key, new Text("" + counter));
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length != 3) {
            System.err.println("Usage: exampleTwitter <in>  <out> <name>");
            System.exit(2);
        }
        Job job = new Job(conf, "Twitter Reader");
        job.getConfiguration().set("newLang", otherArgs[2]);
        job.setJarByClass(MapReduce4v1.class);
        job.setMapperClass(LanguageMapper.class);
        job.setReducerClass(LanguageReducer.class);
        job.setCombinerClass(LanguageReducer.class);
        job.setNumReduceTasks(1);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(Text.class);
        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}