org.apache.tez.mapreduce.examples

Class MapredWordCount

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.tez.mapreduce.examples.MapredWordCount

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

public class MapredWordCount
extends org.apache.hadoop.conf.Configured
implements org.apache.hadoop.util.Tool

This is an example Hadoop Map/Reduce application using the mapred apis. 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 examples.jar wordcount [-m maps] [-r reduces] in-dir out-dir

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MapredWordCount.MapClass Counts the words in each line.
static class	MapredWordCount.Reduce A reducer class that just emits the sum of the input values.

Constructor Summary

Constructors

Constructor and Description
MapredWordCount()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)
int	run(String[] args) The main driver for word count map/reduce program.

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Constructor Detail

MapredWordCount

public MapredWordCount()

Method Detail

run

public int run(String[] args)
        throws Exception

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

Specified by:

run in interface org.apache.hadoop.util.Tool

Throws:

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

Exception

main

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

Throws:

Exception