Package io.github.nejckorasa

Class CollectionPartitioner

java.lang.Object

io.github.nejckorasa.CollectionPartitioner

public final class CollectionPartitioner
extends Object

Utils class used to partition collection based on key extractor

Constructor Summary

Constructors

Constructor	Description
CollectionPartitioner()

Method Summary

Modifier and Type	Method	Description
static <O> Map<Serializable,O>	buildPartition(Collection<O> collection, Function<O,Serializable> keyExtractor)	Builds partition of collection using keyExtractor.
static <O> boolean	canPartition(Collection<O> collection, Function<O,Serializable> keyExtractor)	Checks if collection can be partitioned using key extracted using provided keyExtractor

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionPartitioner

public CollectionPartitioner()

Method Detail

canPartition

public static <O> boolean canPartition(Collection<O> collection,
                                       Function<O,Serializable> keyExtractor)

Checks if collection can be partitioned using key extracted using provided keyExtractor

Type Parameters:

O - objects generic type

Parameters:

collection - collection to partition

keyExtractor - key extractor used to extract keys from items in collection

Returns:

true if collection can be partitioned

buildPartition

public static <O> Map<Serializable,O> buildPartition(Collection<O> collection,
                                                           Function<O,Serializable> keyExtractor)

Builds partition of collection using keyExtractor.

Partitioning is successful if all keys extracted from items in collection are unique and nonnull. If more than one item has the same key, only the first item will exist in result partition.

Use canPartition(Collection, Function) to check if collection can be partitioned.

Type Parameters:

O - objects generic type

Parameters:

collection - collection to partition

keyExtractor - key extractor used to extract keys from items in collection

Returns:

map with collection items as values and it's keys as keys