org.apache.hadoop.mapreduce.lib.partition

类 HashPartitioner<K,V>

java.lang.Object

org.apache.hadoop.mapreduce.Partitioner<K,V>

org.apache.hadoop.mapreduce.lib.partition.HashPartitioner<K,V>

public class HashPartitioner<K,V>
extends Partitioner<K,V>

Partition keys by their Object.hashCode().

构造器概要

构造器

构造器和说明
HashPartitioner()

方法概要

方法

限定符和类型	方法和说明
int	getPartition(K key, V value, int numReduceTasks) Use Object.hashCode() to partition.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

HashPartitioner

public HashPartitioner()

方法详细资料

getPartition

public int getPartition(K key,
               V value,
               int numReduceTasks)

Use Object.hashCode() to partition.

指定者:

getPartition 在类中 Partitioner<K,V>

参数:

key - the key to be partioned.

value - the entry value.

numReduceTasks - the total number of partitions.

返回:

the partition number for the key.