Added in API level 35

RandomGeneratorFactory

class RandomGeneratorFactory<T : RandomGenerator!>

kotlin.Any
↳	java.util.random.RandomGeneratorFactory

This is a factory class for generating multiple random number generators of a specific algorithm. RandomGeneratorFactory also provides methods for selecting random number generator algorithms. A specific RandomGeneratorFactory can be located by using the RandomGeneratorFactory.of(String) method, where the argument string is the name of the algorithm required. The method RandomGeneratorFactory.all() produces a non-empty Stream of all available RandomGeneratorFactorys that can be searched to locate a RandomGeneratorFactory suitable to the task. There are three methods for constructing a RandomGenerator instance, depending on the type of initial seed required. RandomGeneratorFactory.create(long) is used for long seed construction, RandomGeneratorFactory.create(byte[]) is used for byte[] seed construction, and RandomGeneratorFactory.create() is used for random seed construction. Example;

<code>RandomGeneratorFactory&lt;RandomGenerator&gt; factory = RandomGeneratorFactory.of("Random");
 
      for (int i = 0; i &lt; 10; i++) {
          new Thread(() -&gt; {
              RandomGenerator random = factory.create(100L);
              System.out.println(random.nextDouble());
          }).start();
      }
  </code>

RandomGeneratorFactory also provides methods describing the attributes (or properties) of a generator and can be used to select random number generator algorithms. These methods are typically used in conjunction with RandomGeneratorFactory.all(). In this example, the code locates the RandomGeneratorFactory that produces RandomGenerators with the highest number of state bits.

<code>RandomGeneratorFactory&lt;RandomGenerator&gt; best = RandomGeneratorFactory.all()
          .sorted(Comparator.comparingInt(RandomGenerator::stateBits).reversed())
          .findFirst()
          .orElse(RandomGeneratorFactory.of("Random"));
      System.out.println(best.name() + " in " + best.group() + " was selected");
 
      RandomGenerator rng = best.create();
      System.out.println(rng.nextLong());
  </code>

Summary

Public methods
static Stream<RandomGeneratorFactory<RandomGenerator!>!>!	`all()` Returns a non-empty stream of available `RandomGeneratorFactory(s)`.
T	`create()` Create an instance of `RandomGenerator` based on algorithm chosen.
T	`create(seed: ByteArray!)` Create an instance of `RandomGenerator` based on algorithm chosen providing a starting byte[] seed.
T	`create(seed: Long)` Create an instance of `RandomGenerator` based on algorithm chosen providing a starting long seed.
Int	`equidistribution()` Returns the equidistribution of the algorithm.
static RandomGeneratorFactory<RandomGenerator!>!	`getDefault()` Returns a `RandomGeneratorFactory` meeting the minimal requirement of having an algorithm whose state bits are greater than or equal 64.
String!	`group()` Return the group name of the algorithm used by the random number generator.
Boolean	`isArbitrarilyJumpable()` Return true if random generator can jump an arbitrarily specified distant point in the state cycle.
Boolean	`isDeprecated()` Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
Boolean	`isHardware()` Return true if random generator uses a hardware device (HRNG) to produce entropic input.
Boolean	`isJumpable()` Return true if random generator can jump a specified distant point in the state cycle.
Boolean	`isLeapable()` Return true if random generator is jumpable and can leap to a very distant point in the state cycle.
Boolean	`isSplittable()` Return true if random generator can be cloned into a separate object with the same properties but positioned further in the state cycle.
Boolean	`isStatistical()` Return true if random generator is computed using an arithmetic algorithm and is statistically deterministic.
Boolean	`isStochastic()` Return true if random generator is computed using external or entropic sources as inputs.
Boolean	`isStreamable()` Return true if random generator can be used to create `Streams` of random numbers.
String!	`name()` Return the name of the algorithm used by the random number generator.
static RandomGeneratorFactory<T>!	`of(name: String!)` Returns a `RandomGeneratorFactory` that can produce instances of `RandomGenerator` that utilize the `name` algorithm.
BigInteger!	`period()` Return the period of the algorithm used by the random number generator.
Int	`stateBits()` Returns number of bits used by the algorithm to maintain state of seed.

Public methods

all

Added in API level 35

static fun all(): Stream<RandomGeneratorFactory<RandomGenerator!>!>!

Returns a non-empty stream of available RandomGeneratorFactory(s). RandomGenerators that are marked as deprecated are not included in the result.

Return
`Stream<RandomGeneratorFactory<RandomGenerator!>!>!`	a non-empty stream of all available `RandomGeneratorFactory(s)`.

create

Added in API level 35

fun create(): T

Create an instance of RandomGenerator based on algorithm chosen.

Return
`T`	new in instance of `RandomGenerator`.

create

Added in API level 35

fun create(seed: ByteArray!): T

Create an instance of RandomGenerator based on algorithm chosen providing a starting byte[] seed. If byte[] seed is not supported by an algorithm then the no argument form of create is used.

Parameters
`seed`	ByteArray!: byte array random seed value.

Return
`T`	new in instance of `RandomGenerator`.

Exceptions
`java.lang.NullPointerException`	if seed is null.

create

Added in API level 35

fun create(seed: Long): T

Create an instance of RandomGenerator based on algorithm chosen providing a starting long seed. If long seed is not supported by an algorithm then the no argument form of create is used.

Parameters
`seed`	Long: long random seed value.

Return
`T`	new in instance of `RandomGenerator`.

equidistribution

Added in API level 35

fun equidistribution(): Int

Returns the equidistribution of the algorithm.

Return
`Int`	the equidistribution of the algorithm.

getDefault

Added in API level 35

static fun getDefault(): RandomGeneratorFactory<RandomGenerator!>!

Returns a RandomGeneratorFactory meeting the minimal requirement of having an algorithm whose state bits are greater than or equal 64.

Return
`RandomGeneratorFactory<RandomGenerator!>!`	a `RandomGeneratorFactory`

group

Added in API level 35

fun group(): String!

Return the group name of the algorithm used by the random number generator.

Return
`String!`	Group name of the algorithm.

isArbitrarilyJumpable

Added in API level 35

fun isArbitrarilyJumpable(): Boolean

Return true if random generator can jump an arbitrarily specified distant point in the state cycle.

Return
`Boolean`	true if random generator is arbitrarily jumpable.

isDeprecated

Added in API level 35

fun isDeprecated(): Boolean

Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.

Return
`Boolean`	true if the implementation of RandomGenerator (algorithm) has been marked for deprecation

isHardware

Added in API level 35

fun isHardware(): Boolean

Return true if random generator uses a hardware device (HRNG) to produce entropic input.

Return
`Boolean`	true if random generator is generated by hardware.

isJumpable

Added in API level 35

fun isJumpable(): Boolean

Return true if random generator can jump a specified distant point in the state cycle.

Return
`Boolean`	true if random generator is jumpable.

isLeapable

Added in API level 35

fun isLeapable(): Boolean

Return true if random generator is jumpable and can leap to a very distant point in the state cycle.

Return
`Boolean`	true if random generator is leapable.

isSplittable

Added in API level 35

fun isSplittable(): Boolean

Return true if random generator can be cloned into a separate object with the same properties but positioned further in the state cycle.

Return
`Boolean`	true if random generator is splittable.

isStatistical

Added in API level 35

fun isStatistical(): Boolean

Return true if random generator is computed using an arithmetic algorithm and is statistically deterministic.

Return
`Boolean`	true if random generator is statistical.

isStochastic

Added in API level 35

fun isStochastic(): Boolean

Return true if random generator is computed using external or entropic sources as inputs.

Return
`Boolean`	true if random generator is stochastic.

isStreamable

Added in API level 35

fun isStreamable(): Boolean

Return true if random generator can be used to create Streams of random numbers.

Return
`Boolean`	true if random generator is streamable.

name

Added in API level 35

fun name(): String!

Return the name of the algorithm used by the random number generator.

Return
`String!`	Name of the algorithm.

of

Added in API level 35

static fun <T : RandomGenerator!> of(name: String!): RandomGeneratorFactory<T>!

Returns a RandomGeneratorFactory that can produce instances of RandomGenerator that utilize the name algorithm.

Parameters
`name`	String!: Name of random number generator algorithm
`<T>`	Sub-interface of `RandomGenerator` to produce

Return
`RandomGeneratorFactory<T>!`	`RandomGeneratorFactory` of `RandomGenerator`

Exceptions
`java.lang.NullPointerException`	if name is null
`java.lang.IllegalArgumentException`	if the named algorithm is not found

period

Added in API level 35

fun period(): BigInteger!

Return the period of the algorithm used by the random number generator. Returns BigInteger.ZERO if period is not determinable.

Return
`BigInteger!`	BigInteger period.

stateBits

Added in API level 35

fun stateBits(): Int

Returns number of bits used by the algorithm to maintain state of seed.

Return
`Int`	number of bits used by the algorithm to maintain state of seed.