package test.invertedIndex

import java.io.IOException;
import java.util.Iterator;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;

import scala.collection.JavaConversions._

class invertedReducer() extends MapReduceBase
        with Reducer[Text, Text, Text, Text] {

    val finalValue = new Text();

    def reduce(key : Text,
        values: Iterator[Text],
        output: OutputCollector[Text, Text] ,
        reporter: Reporter) {

    // Take all the values and concatinate them together with a , in between them
        finalValue.set(values.foldLeft("")(_ +"," +_) )

        output.collect(key, finalValue);
    }
}