Analysis.A4_High_Traffic_Countries.Top_10_Countries_by_User_Traffic_Reducer.java Source code

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Here is the source code for Analysis.A4_High_Traffic_Countries.Top_10_Countries_by_User_Traffic_Reducer.java

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package Analysis.A4_High_Traffic_Countries;

import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

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

/**
 *
 * @author Chintan
 */
public class Top_10_Countries_by_User_Traffic_Reducer extends Reducer<Text, IntWritable, Text, IntWritable> {
    private TreeMap<Integer, String> top10 = new TreeMap<Integer, String>(Collections.reverseOrder());

    public void reduce(Text key, Iterable<IntWritable> values, Context context)
            throws IOException, InterruptedException {
        int count = 0;
        for (IntWritable value : values) {
            count += value.get();
        }

        //add this country with its play count to tree map
        top10.put(count, key.toString());

        // if map size has grown > 10 then remove first entry as tree map sorts in ascending order
        if (top10.size() > 20) {
            top10.remove(top10.lastKey());
        }
    }

    // Will be called once all keys are parsed
    @Override
    protected void cleanup(Context context) throws IOException, InterruptedException {
        for (Map.Entry<Integer, String> entry : top10.entrySet()) {

            IntWritable result = new IntWritable();

            //Integer key = entry.getKey();
            String value = entry.getValue().substring(0, 1).toUpperCase() + entry.getValue().substring(1);

            result.set(entry.getKey());

            // print top 10 counntries
            context.write(new Text(value), result);
        }
    }

}