## Package org.apache.hadoop.examples

Hadoop example code.

See:
Description

Class Summary
AggregateWordCount: This is an example Aggregated Hadoop Map/Reduce application.
AggregateWordCount.WordCountPlugInClass
AggregateWordHistogram: This is an example Aggregated Hadoop Map/Reduce application.
AggregateWordHistogram.AggregateWordHistogramPlugin
DBCountPageView: This is a demonstrative program, which uses DBInputFormat for reading the input data from a database, and DBOutputFormat for writing the data to the database.
ExampleDriver: A description of an example program based on its class and a human-readable description.
Grep
Join: This is the trivial map/reduce program that does absolutely nothing other than use the framework to fragment and sort the input values.
MultiFileWordCount: MultiFileWordCount is an example to demonstrate the usage of MultiFileInputFormat.
MultiFileWordCount.MapClass: This Mapper is similar to the one in `MultiFileWordCount.MapClass`.
MultiFileWordCount.MultiFileLineRecordReader: RecordReader is responsible from extracting records from the InputSplit.
MultiFileWordCount.MyInputFormat: To use `MultiFileInputFormat`, one should extend it, to return a (custom) `RecordReader`.
MultiFileWordCount.WordOffset: This record keeps <filename,offset> pairs.
PiEstimator: A Map-reduce program to estimate the value of Pi using quasi-Monte Carlo method.
PiEstimator.PiMapper: Mapper class for Pi estimation.
PiEstimator.PiReducer: Reducer class for Pi estimation.
RandomTextWriter: This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task writes a large unsorted random sequence of words.
RandomWriter: This program uses map/reduce to just run a distributed job where there is no interaction between the tasks and each task write a large unsorted random binary sequence file of BytesWritable.
SecondarySort: This is an example Hadoop Map/Reduce application.
SecondarySort.FirstGroupingComparator: Compare only the first part of the pair, so that reduce is called once for each value of the first part.
SecondarySort.FirstPartitioner: Partition based on the first part of the pair.
SecondarySort.IntPair: Define a pair of integers that are writable.
SecondarySort.IntPair.Comparator: A Comparator that compares serialized IntPair.
SecondarySort.MapClass: Read two integers from each line and generate a key, value pair as ((left, right), right).
SecondarySort.Reduce: A reducer class that just emits the sum of the input values.
SleepJob: Dummy class for testing MR framefork.
SleepJob.EmptySplit
SleepJob.SleepInputFormat
Sort<K,V>: This is the trivial map/reduce program that does absolutely nothing other than use the framework to fragment and sort the input values.
WordCount
WordCount.IntSumReducer
WordCount.TokenizerMapper

## Package org.apache.hadoop.examples Description

Hadoop example code.

Copyright © 2009 The Apache Software Foundation