MinMaxCountReducer.java Source code

Introduction

Here is the source code for MinMaxCountReducer.java

Source

import java.io.IOException;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableReducer;
import org.apache.hadoop.hbase.util.Bytes;
import static org.apache.hadoop.hbase.util.Bytes.toBytes;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author Aditia Rakhmat S
 */
public class MinMaxCountReducer extends TableReducer<Text, MinMaxCountTupple, ImmutableBytesWritable> {

    //output value writable
    private MinMaxCountTupple result = new MinMaxCountTupple();

    @Override
    protected void reduce(Text key, Iterable<MinMaxCountTupple> values, Context context)
            throws IOException, InterruptedException {
        //Initialize result
        result.setMax(-100);
        result.setMin(100);
        int sum = 0;

        for (MinMaxCountTupple val : values) {

            if (val.getMin() < result.getMin()) {
                result.setMin(val.getMin());
            }

            if (val.getMax() > result.getMax()) {
                result.setMax(val.getMax());
            }

            sum += val.getCount();

        }

        result.setCount(sum);

        Put put = new Put(toBytes(key.toString()));
        put.add(Bytes.toBytes("cf"), toBytes("min"), toBytes(result.getMin()));
        put.add(Bytes.toBytes("cf"), toBytes("max"), toBytes(result.getMax()));
        put.add(Bytes.toBytes("cf"), toBytes("count"), toBytes(result.getCount()));

        System.out.println(
                "R-> " + key.toString() + " " + result.getMin() + " " + result.getMax() + " " + result.getCount());

        context.write(null, put);
    }

}