Class KeyFieldBasedPartitioner<K2,V2>

  extended by org.apache.hadoop.mapreduce.Partitioner<K2,V2>
      extended by org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedPartitioner<K2,V2>
          extended by org.apache.hadoop.mapred.lib.KeyFieldBasedPartitioner<K2,V2>
All Implemented Interfaces:
Configurable, JobConfigurable, Partitioner<K2,V2>

public class KeyFieldBasedPartitioner<K2,V2>
extends KeyFieldBasedPartitioner<K2,V2>
implements Partitioner<K2,V2>

Defines a way to partition keys based on certain key fields (also see KeyFieldBasedComparator. The key specification supported is of the form -k pos1[,pos2], where, pos is of the form f[.c][opts], where f is the number of the key field to use, and c is the number of the first character from the beginning of the field. Fields and character posns are numbered starting with 1; a character position of zero in pos2 indicates the field's last character. If '.c' is omitted from pos1, it defaults to 1 (the beginning of the field); if omitted from pos2, it defaults to 0 (the end of the field).

Field Summary
Fields inherited from class org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedPartitioner
Constructor Summary
Method Summary
 void configure(JobConf job)
          Initializes a new instance from a JobConf.
Methods inherited from class org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedPartitioner
getConf, getKeyFieldPartitionerOption, getPartition, getPartition, hashCode, setConf, setKeyFieldPartitionerOptions
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.hadoop.mapred.Partitioner

Constructor Detail


public KeyFieldBasedPartitioner()
Method Detail


public void configure(JobConf job)
Description copied from interface: JobConfigurable
Initializes a new instance from a JobConf.

Specified by:
configure in interface JobConfigurable
job - the configuration

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