@InterfaceAudience.Public @InterfaceStability.Stable public class ValueAggregatorCombiner<K1 extends WritableComparable,V1 extends Writable> extends ValueAggregatorJobBase<K1,V1>
aggregatorDescriptorList| Constructor and Description | 
|---|
| ValueAggregatorCombiner() | 
| Modifier and Type | Method and Description | 
|---|---|
| void | close()Do nothing. | 
| void | configure(JobConf job)Combiner does not need to configure. | 
| void | map(K1 arg0,
   V1 arg1,
   OutputCollector<Text,Text> arg2,
   Reporter arg3)Do nothing. | 
| void | reduce(Text key,
      Iterator<Text> values,
      OutputCollector<Text,Text> output,
      Reporter reporter)Combines values for a given key. | 
logSpecpublic void configure(JobConf job)
configure in interface JobConfigurableconfigure in class ValueAggregatorJobBase<K1 extends WritableComparable,V1 extends Writable>job - the configurationpublic void reduce(Text key, Iterator<Text> values, OutputCollector<Text,Text> output, Reporter reporter) throws IOException
key - the key is expected to be a Text object, whose prefix indicates
 the type of aggregation to aggregate the values.values - the values to combineoutput - to collect combined valuesreporter - facility to report progress.IOExceptionpublic void close()
           throws IOException
close in interface Closeableclose in interface AutoCloseableclose in class ValueAggregatorJobBase<K1 extends WritableComparable,V1 extends Writable>IOExceptionpublic void map(K1 arg0, V1 arg1, OutputCollector<Text,Text> arg2, Reporter arg3) throws IOException
arg0 - the input key.arg1 - the input value.arg2 - collects mapped keys and values.arg3 - facility to report progress.IOExceptionCopyright © 2023 Apache Software Foundation. All rights reserved.