org.apache.spark

Class HashPartitioner

Object

org.apache.spark.Partitioner

org.apache.spark.HashPartitioner

All Implemented Interfaces:

java.io.Serializable

public class HashPartitioner
extends Partitioner

A Partitioner that implements hash-based partitioning using Java's Object.hashCode.

Java arrays have hashCodes that are based on the arrays' identities rather than their contents, so attempting to partition an RDD[Array[_} or RDD[(Array[_], _)] using a HashPartitioner will produce an unexpected or incorrect result.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
HashPartitioner(int partitions)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object other)
int	getPartition(Object key)
int	hashCode()
int	numPartitions()

Methods inherited from class org.apache.spark.Partitioner

defaultPartitioner

Methods inherited from class Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HashPartitioner

public HashPartitioner(int partitions)

Method Detail

numPartitions

public int numPartitions()

Specified by:

numPartitions in class Partitioner

getPartition

public int getPartition(Object key)

Specified by:

getPartition in class Partitioner

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object