io.cdap.cdap.api.dataset.lib

Class DynamicPartitioner<K,V>

java.lang.Object

io.cdap.cdap.api.dataset.lib.DynamicPartitioner<K,V>

Type Parameters:

K - Type of key

V - Type of value

public abstract class DynamicPartitioner<K,V>
extends Object

Responsible for dynamically determining a @{link PartitionKey}. For each K, V pair, the getPartitionKey(K, V) method is called to determine a PartitionKey.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DynamicPartitioner.PartitionWriteOption Defines options for when writing to a partition.

Constructor Summary

Constructors

Constructor and Description
DynamicPartitioner()

Method Summary

Modifier and Type	Method and Description
void	destroy() Destroys a DynamicPartitioner.
abstract PartitionKey	getPartitionKey(K key, V value) Determine the PartitionKey for the key-value pair to be written to.
void	initialize(MapReduceTaskContext<K,V> mapReduceTaskContext) Initializes a DynamicPartitioner.

Methods inherited from class java.lang.Object

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

Constructor Detail

DynamicPartitioner

public DynamicPartitioner()

Method Detail

initialize

public void initialize(MapReduceTaskContext<K,V> mapReduceTaskContext)

Initializes a DynamicPartitioner.

This method will be called only once per DynamicPartitioner instance. It is the first method call on that instance.

Parameters:

mapReduceTaskContext - the mapReduceTaskContext for the task that this DynamicPartitioner is running in. Note that the hadoop context is not available on this MapReduceTaskContext.

destroy

public void destroy()

Destroys a DynamicPartitioner.

This method will be called only once per DynamicPartitioner instance. It is the last method call on that instance.

getPartitionKey

public abstract PartitionKey getPartitionKey(K key,
                                             V value)

Determine the PartitionKey for the key-value pair to be written to.

Parameters:

key - the key to be written

value - the value to be written

Returns:

the PartitionKey for the key-value pair to be written to.