Added in API level 35

Summary: Methods | Inherited Methods

RandomGenerator.LeapableGenerator

public static interface RandomGenerator.LeapableGenerator
implements RandomGenerator.JumpableGenerator

java.util.random.RandomGenerator.LeapableGenerator

Known indirect subclasses

RandomGenerator.ArbitrarilyJumpableGenerator

RandomGenerator.ArbitrarilyJumpableGenerator This interface is designed to provide a common protocol for objects that generate sequences of pseudorandom values and can easily jump forward, by an arbitrary amount, to a distant point in the state cycle.

This interface is designed to provide a common protocol for objects that generate sequences of pseudorandom values and can easily not only jump but also leap forward, by a large amount (ex. 2¹²⁸), to a very distant point in the state cycle. Typically one will construct a series of LeapableGenerator objects by iterative leaping from a single original LeapableGenerator object, and then for each such object produce a subseries of objects by iterative jumping. There is little conceptual difference between leaping and jumping, but typically a leap will be a very long jump in the state cycle (perhaps distance 2¹²⁸ or so).

Ideally, all LeapableGenerator objects produced by iterative leaping and jumping from a single original LeapableGenerator object are statistically independent of one another and individually uniform. In practice, one must settle for some approximation to independence and uniformity. In particular, a specific implementation may assume that each generator in a stream produced by the leaps method is used to produce (by jumping) a number of objects no larger than 2⁶⁴. Implementors are advised to use algorithms whose period is at least 2¹⁹¹.

Methods are provided to perform a single leap operation and also to produce a stream of generators produced from the original by iterative copying and leaping of internal state. The generators produced must implement the JumpableGenerator interface but need not also implement the LeapableGenerator interface. A typical strategy for a multithreaded application is to create a single LeapableGenerator object, calls its leaps method exactly once, and then parcel out generators from the resulting stream, one to each thread. Then the jump() method of each such generator be called to produce a substream of generator objects.

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

Summary

Public methods
`abstract RandomGenerator.LeapableGenerator`	`copy()` Returns a new generator whose internal state is an exact copy of this generator (therefore their future behavior should be identical if subjected to the same series of operations).
`default RandomGenerator.JumpableGenerator`	`copyAndLeap()` Copy this generator, leap this generator forward, then return the copy.
`abstract void`	`leap()` Alter the state of this pseudorandom number generator so as to leap forward a large, fixed distance (typically 2⁹⁶ or more) within its state cycle.
`abstract double`	`leapDistance()` Returns the distance by which the `leap`() method will leap forward within the state cycle of this generator object.
`default Stream<RandomGenerator.JumpableGenerator>`	`leaps()` Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the `JumpableGenerator` interface.
`default Stream<RandomGenerator.JumpableGenerator>`	`leaps(long streamSize)` Returns a stream producing the given `streamSize` number of new pseudorandom number generators, each of which implements the `JumpableGenerator` interface.
`static RandomGenerator.LeapableGenerator`	`of(String name)` Returns an instance of `LeapableGenerator` that utilizes the `name` algorithm.

Inherited methods

From interface


        
          java.util.random.RandomGenerator.JumpableGenerator

`abstract RandomGenerator.JumpableGenerator`	`copy()` Returns a new generator whose internal state is an exact copy of this generator (therefore their future behavior should be identical if subjected to the same series of operations).
`default RandomGenerator`	`copyAndJump()` Copy this generator, jump this generator forward, then return the copy.
`abstract void`	`jump()` Alter the state of this pseudorandom number generator so as to jump forward a large, fixed distance (typically 2⁶⁴ or more) within its state cycle.
`abstract double`	`jumpDistance()` Returns the distance by which the `jump`() method will jump forward within the state cycle of this generator object.
`default Stream<RandomGenerator>`	`jumps(long streamSize)` Returns a stream producing the given `streamSize` number of new pseudorandom number generators, each of which implements the `RandomGenerator` interface.
`default Stream<RandomGenerator>`	`jumps()` Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the `RandomGenerator` interface.
`static RandomGenerator.JumpableGenerator`	`of(String name)` Returns an instance of `JumpableGenerator` that utilizes the `name` algorithm.
`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.
`default Stream<RandomGenerator>`	`rngs()` Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the `RandomGenerator` interface.

From interface


        
          java.util.random.RandomGenerator.StreamableGenerator

`static RandomGenerator.StreamableGenerator`	`of(String name)` Returns an instance of `StreamableGenerator` that utilizes the `name` algorithm.
`default Stream<RandomGenerator>`	`rngs(long streamSize)` Returns an effectively unlimited stream of objects, each of which implements the `RandomGenerator` interface.
`abstract Stream<RandomGenerator>`	`rngs()` Returns an effectively unlimited stream of objects, each of which implements the `RandomGenerator` interface.

From interface


        
          java.util.random.RandomGenerator

`default DoubleStream`	`doubles(long streamSize, double randomNumberOrigin, double randomNumberBound)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `double` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`default DoubleStream`	`doubles(long streamSize)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `double` values.
`default DoubleStream`	`doubles()` Returns an effectively unlimited stream of pseudorandomly chosen `double` values.
`default DoubleStream`	`doubles(double randomNumberOrigin, double randomNumberBound)` Returns an effectively unlimited stream of pseudorandomly chosen `double` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`static RandomGenerator`	`getDefault()` Returns a `RandomGenerator` meeting the minimal requirement of having an algorithm whose state bits are greater than or equal 64.
`default IntStream`	`ints(long streamSize)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `int` values.
`default IntStream`	`ints(int randomNumberOrigin, int randomNumberBound)` Returns an effectively unlimited stream of pseudorandomly chosen `int` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`default IntStream`	`ints()` Returns an effectively unlimited stream of pseudorandomly chosen `int` values.
`default IntStream`	`ints(long streamSize, int randomNumberOrigin, int randomNumberBound)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `int` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`default boolean`	`isDeprecated()` Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
`default LongStream`	`longs(long streamSize)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `long` values.
`default LongStream`	`longs()` Returns an effectively unlimited stream of pseudorandomly chosen `long` values.
`default LongStream`	`longs(long randomNumberOrigin, long randomNumberBound)` Returns an effectively unlimited stream of pseudorandomly chosen `long` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`default LongStream`	`longs(long streamSize, long randomNumberOrigin, long randomNumberBound)` Returns a stream producing the given `streamSize` number of pseudorandomly chosen `long` values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
`default boolean`	`nextBoolean()` Returns a pseudorandomly chosen `boolean` value.
`default void`	`nextBytes(byte[] bytes)` Fills a user-supplied byte array with generated byte values pseudorandomly chosen uniformly from the range of values between -128 (inclusive) and 127 (inclusive).
`default double`	`nextDouble()` Returns a pseudorandom `double` value between zero (inclusive) and one (exclusive).
`default double`	`nextDouble(double bound)` Returns a pseudorandomly chosen `double` value between zero (inclusive) and the specified bound (exclusive).
`default double`	`nextDouble(double origin, double bound)` Returns a pseudorandomly chosen `double` value between the specified origin (inclusive) and the specified bound (exclusive).
`default double`	`nextExponential()` Returns a nonnegative `double` value pseudorandomly chosen from an exponential distribution whose mean is 1.
`default float`	`nextFloat(float origin, float bound)` Returns a pseudorandomly chosen `float` value between the specified origin (inclusive) and the specified bound (exclusive).
`default float`	`nextFloat()` Returns a pseudorandom `float` value between zero (inclusive) and one (exclusive).
`default float`	`nextFloat(float bound)` Returns a pseudorandomly chosen `float` value between zero (inclusive) and the specified bound (exclusive).
`default double`	`nextGaussian(double mean, double stddev)` Returns a `double` value pseudorandomly chosen from a Gaussian (normal) distribution with a mean and standard deviation specified by the arguments.
`default double`	`nextGaussian()` Returns a `double` value pseudorandomly chosen from a Gaussian (normal) distribution whose mean is 0 and whose standard deviation is 1.
`default int`	`nextInt(int origin, int bound)` Returns a pseudorandomly chosen `int` value between the specified origin (inclusive) and the specified bound (exclusive).
`default int`	`nextInt()` Returns a pseudorandomly chosen `int` value.
`default int`	`nextInt(int bound)` Returns a pseudorandomly chosen `int` value between zero (inclusive) and the specified bound (exclusive).
`default long`	`nextLong(long origin, long bound)` Returns a pseudorandomly chosen `long` value between the specified origin (inclusive) and the specified bound (exclusive).
`default long`	`nextLong(long bound)` Returns a pseudorandomly chosen `long` value between zero (inclusive) and the specified bound (exclusive).
`abstract long`	`nextLong()` Returns a pseudorandomly chosen `long` value.
`static RandomGenerator`	`of(String name)` Returns an instance of `RandomGenerator` that utilizes the `name` algorithm.

Public methods

copy

Added in API level 35

public abstract RandomGenerator.LeapableGenerator copy ()

Returns a new generator whose internal state is an exact copy of this generator (therefore their future behavior should be identical if subjected to the same series of operations).

Returns
`RandomGenerator.LeapableGenerator`	a new object that is a copy of this generator

copyAndLeap

Added in API level 35

public RandomGenerator.JumpableGenerator copyAndLeap ()

Copy this generator, leap this generator forward, then return the copy.

Implementation Requirements:

The default implementation copies this, leaps and then returns the copy.

Returns
`RandomGenerator.JumpableGenerator`	a copy of this generator object before the leap occurred

leap

Added in API level 35

public abstract void leap ()

Alter the state of this pseudorandom number generator so as to leap forward a large, fixed distance (typically 2⁹⁶ or more) within its state cycle.

leapDistance

Added in API level 35

public abstract double leapDistance ()

Returns the distance by which the leap() method will leap forward within the state cycle of this generator object.

Returns
`double`	the default leap distance (as a `double` value)

leaps

Added in API level 35

public Stream<RandomGenerator.JumpableGenerator> leaps ()

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

Implementation Note:

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

Implementation Requirements:

The default implementation produces a sequential stream that repeatedly calls copy() and leap() on this generator, and the copies become the generators produced by the stream.

Returns
`Stream<RandomGenerator.JumpableGenerator>`	a stream of objects that implement the `JumpableGenerator` interface

leaps

Added in API level 35

public Stream<RandomGenerator.JumpableGenerator> leaps (long streamSize)

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

Implementation Requirements:

The default implementation produces a sequential stream that repeatedly calls copy() and leap() on this generator, and the copies become the generators produced by the stream.

Parameters
`streamSize`	`long`: the number of generators to generate

Returns
`Stream<RandomGenerator.JumpableGenerator>`	a stream of objects that implement the `JumpableGenerator` interface

Throws
`IllegalArgumentException`	if `streamSize` is less than zero

of

Added in API level 35

public static RandomGenerator.LeapableGenerator of (String name)

Returns an instance of LeapableGenerator that utilizes the name algorithm.

Parameters
`name`	`String`: Name of random number generator algorithm

Returns
`RandomGenerator.LeapableGenerator`	An instance of `LeapableGenerator`

Throws
`NullPointerException`	if name is null
`IllegalArgumentException`	if the named algorithm is not found