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

java.lang.Object
  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>

@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


Copyright © 2012 Apache Software Foundation. All Rights Reserved.