org.apache.hadoop.mapred.lib
Class HashPartitioner<K2,V2>
java.lang.Object
org.apache.hadoop.mapred.lib.HashPartitioner<K2,V2>
- All Implemented Interfaces:
- JobConfigurable, Partitioner<K2,V2>
public class HashPartitioner<K2,V2>
- extends Object
- implements Partitioner<K2,V2>
Partition keys by their Object.hashCode().
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
HashPartitioner
public HashPartitioner()
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
getPartition
public int getPartition(K2 key,
V2 value,
int numReduceTasks)
- Use
Object.hashCode() to partition.
- Specified by:
getPartition in interface Partitioner<K2,V2>
- Parameters:
key - the key to be paritioned.value - the entry value.numReduceTasks - the total number of partitions.
- Returns:
- the partition number for the
key.
Copyright © 2009 The Apache Software Foundation