org.apache.hadoop.examples
Class AggregateWordHistogram.AggregateWordHistogramPlugin

java.lang.Object
  org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorBaseDescriptor
      org.apache.hadoop.examples.AggregateWordHistogram.AggregateWordHistogramPlugin

All Implemented Interfaces:

ValueAggregatorDescriptor

Enclosing class:

AggregateWordHistogram

public static class AggregateWordHistogram.AggregateWordHistogramPlugin
extends ValueAggregatorBaseDescriptor

Field Summary

Fields inherited from class org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorBaseDescriptor

DOUBLE_VALUE_SUM, inputFile, LONG_VALUE_MAX, LONG_VALUE_MIN, LONG_VALUE_SUM, STRING_VALUE_MAX, STRING_VALUE_MIN, UNIQ_VALUE_COUNT, VALUE_HISTOGRAM

Fields inherited from interface org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorDescriptor

ONE, TYPE_SEPARATOR

Constructor Summary

AggregateWordHistogram.AggregateWordHistogramPlugin()

Method Summary

ArrayList<Map.Entry<Text,Text>>

generateKeyValPairs(Object key, Object val) Parse the given value, generate an aggregation-id/value pair per word.

Methods inherited from class org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorBaseDescriptor

configure, generateEntry, generateValueAggregator

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregateWordHistogram.AggregateWordHistogramPlugin

public AggregateWordHistogram.AggregateWordHistogramPlugin()

Method Detail

generateKeyValPairs

public ArrayList<Map.Entry<Text,Text>> generateKeyValPairs(Object key,
                                                           Object val)

Parse the given value, generate an aggregation-id/value pair per word. The ID is of type VALUE_HISTOGRAM, with WORD_HISTOGRAM as the real id. The value is WORD\t1.

Specified by:

generateKeyValPairs in interface ValueAggregatorDescriptor

Overrides:

generateKeyValPairs in class ValueAggregatorBaseDescriptor

Parameters:

key - input key

val - input value

Returns:

a list of the generated pairs.