org.apache.hadoop.mapred.lib
Class KeyFieldBasedPartitioner<K2,V2>

java.lang.Object
  org.apache.hadoop.mapreduce.Partitioner<K2,V2>
      org.apache.hadoop.mapreduce.lib.partition.KeyFieldBasedPartitioner<K2,V2>
          org.apache.hadoop.mapred.lib.KeyFieldBasedPartitioner<K2,V2>

All Implemented Interfaces:

Configurable, JobConfigurable, Partitioner<K2,V2>

@InterfaceAudience.Public
@InterfaceStability.Stable
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

PARTITIONER_OPTIONS

Constructor Summary

KeyFieldBasedPartitioner()

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

getPartition

Constructor Detail

KeyFieldBasedPartitioner

public KeyFieldBasedPartitioner()

Method Detail

configure

public void configure(JobConf job)

Description copied from interface: JobConfigurable

Initializes a new instance from a JobConf.

Specified by:

configure in interface JobConfigurable

Parameters:

job - the configuration