org.apache.hadoop.examples
Class WordCount.MapClass

java.lang.Object
  org.apache.hadoop.mapred.MapReduceBase
      org.apache.hadoop.examples.WordCount.MapClass

All Implemented Interfaces:

Closeable, JobConfigurable, Mapper

Enclosing class:

WordCount

public static class WordCount.MapClass
extends MapReduceBase
implements Mapper

Counts the words in each line. For each line of input, break the line into words and emit them as (word, 1).

Constructor Summary

WordCount.MapClass()

Method Summary

void	map(WritableComparable key, Writable value, OutputCollector output, Reporter reporter) Maps a single input key/value pair into intermediate key/value pairs.

Methods inherited from class org.apache.hadoop.mapred.MapReduceBase

close, configure

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.mapred.JobConfigurable

configure

Methods inherited from interface org.apache.hadoop.io.Closeable

close

Constructor Detail

WordCount.MapClass

public WordCount.MapClass()

Method Detail

map

public void map(WritableComparable key,
                Writable value,
                OutputCollector output,
                Reporter reporter)
         throws IOException

Description copied from interface: Mapper

Maps a single input key/value pair into intermediate key/value pairs. Output pairs need not be of the same types as input pairs. A given input pair may map to zero or many output pairs. Output pairs are collected with calls to OutputCollector.collect(WritableComparable,Writable).

Specified by:

map in interface Mapper

Parameters:

key - the key

value - the values

output - collects mapped keys and values

Throws:

IOException