Module java.base

Package java.util.random

Interface RandomGenerator.SplittableGenerator

All Superinterfaces:

RandomGenerator, RandomGenerator.StreamableGenerator

All Known Implementing Classes:

SplittableRandom

Enclosing interface:

RandomGenerator

public static interface RandomGenerator.SplittableGenerator
extends RandomGenerator.StreamableGenerator

This interface is designed to provide a common protocol for objects that generate sequences of pseudorandom values and can be split into two objects (the original one and a new one) each of which obey that same protocol (and therefore can be recursively split indefinitely).

Ideally, all RandomGenerator.SplittableGenerator objects produced by recursive splitting from a single original RandomGenerator.SplittableGenerator object are statistically independent of one another and individually uniform. Therefore we would expect the set of values collectively generated by a set of such objects to have the same statistical properties as if the same quantity of values were generated by a single thread using a single RandomGenerator.SplittableGenerator object. In practice, one must settle for some approximation to independence and uniformity.

Methods are provided to perform a single splitting operation and also to produce a stream of generators split off from the original (by either iterative or recursive splitting, or a combination).

Objects that implement RandomGenerator.SplittableGenerator are typically not cryptographically secure. Consider instead using SecureRandom to get a cryptographically secure pseudo-random number generator for use by security-sensitive applications.

Nested Class Summary

Nested classes/interfaces declared in interface java.util.random.RandomGenerator

RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator

Method Summary

Modifier and Type	Method	Description
static RandomGenerator.SplittableGenerator	of(String name)	Returns an instance of RandomGenerator.SplittableGenerator that utilizes the name algorithm.
default Stream<RandomGenerator>	rngs()	Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator interface.
default Stream<RandomGenerator>	rngs(long streamSize)	Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator interface.
RandomGenerator.SplittableGenerator	split()	Returns a new pseudorandom number generator, split off from this one, that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces.
RandomGenerator.SplittableGenerator	split(RandomGenerator.SplittableGenerator source)	Returns a new pseudorandom number generator, split off from this one, that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces.
default Stream<RandomGenerator.SplittableGenerator>	splits()	Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.
Stream<RandomGenerator.SplittableGenerator>	splits(long streamSize)	Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.
Stream<RandomGenerator.SplittableGenerator>	splits(long streamSize, RandomGenerator.SplittableGenerator source)	Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.
Stream<RandomGenerator.SplittableGenerator>	splits(RandomGenerator.SplittableGenerator source)	Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.

Methods declared in interface java.util.random.RandomGenerator

doubles, doubles, doubles, doubles, equiDoubles, ints, ints, ints, ints, isDeprecated, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextDouble, nextDouble, nextExponential, nextFloat, nextFloat, nextFloat, nextGaussian, nextGaussian, nextInt, nextInt, nextInt, nextLong, nextLong, nextLong

Method Details

of

static RandomGenerator.SplittableGenerator of(String name)

Returns an instance of RandomGenerator.SplittableGenerator that utilizes the name algorithm.

Parameters:

name - Name of random number generator algorithm

Returns:

An instance of RandomGenerator.SplittableGenerator

Throws:

NullPointerException - if name is null

IllegalArgumentException - if the named algorithm is not found

split

RandomGenerator.SplittableGenerator split()

Returns a new pseudorandom number generator, split off from this one, that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces.

This pseudorandom number generator may be used as a source of pseudorandom bits used to initialize the state of the new one.

Returns:

a new object that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces

split

RandomGenerator.SplittableGenerator split(RandomGenerator.SplittableGenerator source)

Returns a new pseudorandom number generator, split off from this one, that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces.

Parameters:

source - a RandomGenerator.SplittableGenerator instance to be used instead of this one as a source of pseudorandom bits used to initialize the state of the new ones.

Returns:

an object that implements the RandomGenerator and RandomGenerator.SplittableGenerator interfaces

Throws:

NullPointerException - if source is null

splits

default Stream<RandomGenerator.SplittableGenerator> splits()

Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.

This pseudorandom number generator may be used as a source of pseudorandom bits used to initialize the state the new ones.

Implementation Requirements:

The default implementation invokes splits(this).

Implementation Note:

It is permitted to implement this method in a manner equivalent to splits (Long.MAX_VALUE).

Returns:

a stream of RandomGenerator.SplittableGenerator objects

splits

Stream<RandomGenerator.SplittableGenerator> splits(long streamSize)

Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.

This pseudorandom number generator may be used as a source of pseudorandom bits used to initialize the state the new ones.

Parameters:

streamSize - the number of values to generate

Returns:

a stream of RandomGenerator.SplittableGenerator objects

Throws:

IllegalArgumentException - if streamSize is less than zero

splits

Stream<RandomGenerator.SplittableGenerator> splits(RandomGenerator.SplittableGenerator source)

Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.

Implementation Note:

It is permitted to implement this method in a manner equivalent to splits (Long.MAX_VALUE, source).

Parameters:

source - a RandomGenerator.SplittableGenerator instance to be used instead of this one as a source of pseudorandom bits used to initialize the state of the new ones.

Returns:

a stream of RandomGenerator.SplittableGenerator objects

Throws:

NullPointerException - if source is null

splits

Stream<RandomGenerator.SplittableGenerator> splits(long streamSize,
 RandomGenerator.SplittableGenerator source)

Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator.SplittableGenerator interface.

Parameters:

streamSize - the number of values to generate

source - a RandomGenerator.SplittableGenerator instance to be used instead of this one as a source of pseudorandom bits used to initialize the state of the new ones.

Returns:

a stream of RandomGenerator.SplittableGenerator objects

Throws:

IllegalArgumentException - if streamSize is less than zero

NullPointerException - if source is null

rngs

default Stream<RandomGenerator> rngs()

Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator interface. Ideally the generators in the stream will appear to be statistically independent.

Specified by:

rngs in interface RandomGenerator.StreamableGenerator

Implementation Requirements:

The default implementation calls splits().

Returns:

a stream of objects that implement the RandomGenerator interface

rngs

default Stream<RandomGenerator> rngs(long streamSize)

Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator interface. Ideally the generators in the stream will appear to be statistically independent.

Specified by:

rngs in interface RandomGenerator.StreamableGenerator

Implementation Requirements:

The default implementation calls splits(streamSize).

Parameters:

streamSize - the number of generators to generate

Returns:

a stream of objects that implement the RandomGenerator interface

Throws:

IllegalArgumentException - if streamSize is less than zero