org.apache.hadoop.examples
Class WordCount

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

public class WordCount
extends Object

This is an example Hadoop Map/Reduce application. It reads the text input files, breaks each line into words and counts them. The output is a locally sorted list of words and the count of how often they occurred. To run: bin/hadoop jar build/hadoop-examples.jar wordcount [-m maps] [-r reduces] in-dir out-dir

Author:

Owen O'Malley

Nested Class Summary

static class	WordCount.MapClass Counts the words in each line.
static class	WordCount.Reduce A reducer class that just emits the sum of the input values.

Constructor Summary

WordCount()

Method Summary

static void

main(String[] args) The main driver for word count map/reduce program.

Methods inherited from class java.lang.Object

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

Constructor Detail

WordCount

public WordCount()

Method Detail

main

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

The main driver for word count map/reduce program. Invoke this method to submit the map/reduce job.

Throws:

IOException - When there is communication problems with the job tracker.