## 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.

Copyright © 2009 The Apache Software Foundation