@InterfaceAudience.Public @InterfaceStability.Stable public class ValueAggregatorMapper<K1 extends WritableComparable,V1 extends Writable> extends ValueAggregatorJobBase<K1,V1>
aggregatorDescriptorList
Constructor and Description |
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ValueAggregatorMapper() |
Modifier and Type | Method and Description |
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void |
map(K1 key,
V1 value,
OutputCollector<Text,Text> output,
Reporter reporter)
the map function.
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void |
reduce(Text arg0,
Iterator<Text> arg1,
OutputCollector<Text,Text> arg2,
Reporter arg3)
Do nothing.
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close, configure, logSpec
public void map(K1 key, V1 value, OutputCollector<Text,Text> output, Reporter reporter) throws IOException
key
- the input key.value
- the input value.output
- collects mapped keys and values.reporter
- facility to report progress.IOException
public void reduce(Text arg0, Iterator<Text> arg1, OutputCollector<Text,Text> arg2, Reporter arg3) throws IOException
arg0
- the key.arg1
- the list of values to reduce.arg2
- to collect keys and combined values.arg3
- facility to report progress.IOException
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