Package org.apache.hadoop.mapred.lib

Class Summary
BinaryPartitioner<V> Partition BinaryComparable keys using a configurable part of the bytes array returned by BinaryComparable.getBytes().
ChainMapper The ChainMapper class allows to use multiple Mapper classes within a single Map task.
ChainReducer The ChainReducer class allows to chain multiple Mapper classes after a Reducer within the Reducer task.
CombineFileInputFormat<K,V> An abstract InputFormat that returns CombineFileSplit's in InputFormat.getSplits(JobConf, int) method.
CombineFileRecordReader<K,V> A generic RecordReader that can hand out different recordReaders for each chunk in a CombineFileSplit.
CombineFileSplit  
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.
FilterOutputFormat<K,V> FilterOutputFormat is a convenience class that wraps OutputFormat.
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.
InputSampler<K,V>  
InverseMapper<K,V> A Mapper that swaps keys and values.
KeyFieldBasedComparator<K,V> This comparator implementation provides a subset of the features provided by the Unix/GNU Sort.
KeyFieldBasedPartitioner<K2,V2> Defines a way to partition keys based on certain key fields (also see KeyFieldBasedComparator.
LazyOutputFormat<K,V> A Convenience class that creates output lazily.
LongSumReducer<K> A Reducer that sums long values.
MultipleInputs This class supports MapReduce jobs that have multiple input paths with a different InputFormat and Mapper for each path
MultipleOutputFormat<K,V> This abstract class extends the FileOutputFormat, allowing to write the output data to different output files.
MultipleOutputs The MultipleOutputs class simplifies writting to additional outputs other than the job default output via the OutputCollector passed to the map() and reduce() methods of the Mapper and Reducer implementations.
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.
TotalOrderPartitioner<K extends WritableComparable<?>,V> Partitioner effecting a total order by reading split points from an externally generated source.
 



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