com.mapred.JoinReducer.java Source code

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Here is the source code for com.mapred.JoinReducer.java

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package com.mapred;

import java.io.IOException;
import java.util.Iterator;
import java.util.Set;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.MapWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

public class JoinReducer extends Reducer<DepDatePair, MapWritable, LongWritable, Text> {

    Text outputValue = new Text();
    StringBuilder builder = new StringBuilder();
    String departmentName = "";
    Long index;

    protected void reduce(DepDatePair key, Iterable<MapWritable> values, Context context)
            throws IOException, InterruptedException {
        Iterator valuesIterator = values.iterator();
        if (valuesIterator.hasNext()) {
            this.index = 1L;
            MapWritable depMap = (MapWritable) valuesIterator.next();
            this.departmentName = depMap.get(MRUtils.DEPARTMENT_NAME).toString();
            if (this.departmentName == null) {
                this.departmentName = "DEP#NAME#ERROR";
            }
            while (valuesIterator.hasNext()) {
                MapWritable map = (MapWritable) valuesIterator.next();
                Set keySet = map.keySet();
                for (Object singleKey : keySet) {
                    this.builder.append(map.get((Text) singleKey));
                    this.builder.append(",");
                }
                this.builder.append(this.departmentName);
                this.builder.append(";");
                this.outputValue.set(this.builder.toString());
                context.write(new LongWritable(this.index++), outputValue);
                this.builder.delete(0, this.builder.length());
            }
        }

    }

}