Package org.apache.hadoop.mapred.lib

Library of generally useful mappers, reducers, and partitioners.

See:
Description

Class Summary

FieldSelectionMapReduce<K,V>	This class implements a mapper/reducer class that can be used to perform field selections in a manner similar to unix cut.
HashPartitioner<K2,V2>	Partition keys by their Object.hashCode().
IdentityMapper<K,V>	Implements the identity function, mapping inputs directly to outputs.
IdentityReducer<K,V>	Performs no reduction, writing all input values directly to the output.
InverseMapper<K,V>	A Mapper that swaps keys and values.
KeyFieldBasedPartitioner<K2,V2>
LongSumReducer<K>	A Reducer that sums long values.
MultipleOutputFormat<K,V>	This abstract class extends the OutputFormatBase, allowing to write the output data to different output files.
MultipleSequenceFileOutputFormat<K,V>	This class extends the MultipleOutputFormat, allowing to write the output data to different output files in sequence file output format.
MultipleTextOutputFormat<K,V>	This class extends the MultipleOutputFormat, allowing to write the output data to different output files in Text output format.
MultithreadedMapRunner<K1,V1,K2,V2>	Multithreaded implementation for @link org.apache.hadoop.mapred.MapRunnable.
NLineInputFormat	NLineInputFormat which splits N lines of input as one split.
NullOutputFormat<K,V>	Consume all outputs and put them in /dev/null.
RegexMapper<K>	A Mapper that extracts text matching a regular expression.
TokenCountMapper<K>	A Mapper that maps text values into pairs.

Package org.apache.hadoop.mapred.lib Description

Library of generally useful mappers, reducers, and partitioners.