org.apache.hadoop.examples
Class SecondarySort

java.lang.Object
  org.apache.hadoop.examples.SecondarySort

public class SecondarySort
extends Object

This is an example Hadoop Map/Reduce application. It reads the text input files that must contain two integers per a line. The output is sorted by the first and second number and grouped on the first number. To run: bin/hadoop jar build/hadoop-examples.jar secondarysort in-dir out-dir

Nested Class Summary

static class	SecondarySort.FirstGroupingComparator Compare only the first part of the pair, so that reduce is called once for each value of the first part.
static class	SecondarySort.FirstPartitioner Partition based on the first part of the pair.
static class	SecondarySort.IntPair Define a pair of integers that are writable.
static class	SecondarySort.MapClass Read two integers from each line and generate a key, value pair as ((left, right), right).
static class	SecondarySort.Reduce A reducer class that just emits the sum of the input values.

Constructor Summary

SecondarySort()

Method Summary

static void

main(String[] args)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SecondarySort

public SecondarySort()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception