org.apache.hadoop.examples

Class WordMean.WordMeanMapper

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>

org.apache.hadoop.examples.WordMean.WordMeanMapper

Enclosing class:

WordMean

public static class WordMean.WordMeanMapper
extends org.apache.hadoop.mapreduce.Mapper<Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>

Maps words from line of text into 2 key-value pairs; one key-value pair for counting the word, another for counting its length.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Constructor Summary

Constructors

Constructor and Description
WordMean.WordMeanMapper()

Method Summary

Methods

Modifier and Type	Method and Description
void	map(Object key, org.apache.hadoop.io.Text value, org.apache.hadoop.mapreduce.Mapper.Context context) Emits 2 key-value pairs for counting the word and its length.

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

cleanup, run, setup

Methods inherited from class java.lang.Object

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

Constructor Detail

WordMean.WordMeanMapper

public WordMean.WordMeanMapper()

Method Detail

map

public void map(Object key,
       org.apache.hadoop.io.Text value,
       org.apache.hadoop.mapreduce.Mapper.Context context)
         throws IOException,
                InterruptedException

Emits 2 key-value pairs for counting the word and its length. Outputs are (Text, LongWritable).

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.LongWritable>

Parameters:

value - This will be a line of text coming in from our input file.

Throws:

IOException

InterruptedException