 All Superinterfaces:
RandomGenerator
,RandomGenerator.JumpableGenerator
,RandomGenerator.StreamableGenerator
 All Known Subinterfaces:
RandomGenerator.ArbitrarilyJumpableGenerator
 Enclosing interface:
RandomGenerator
RandomGenerator.LeapableGenerator
objects by iterative leaping from a single original
RandomGenerator.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 2^{128} or
so).
Ideally, all RandomGenerator.LeapableGenerator
objects produced by iterative
leaping and jumping from a single original RandomGenerator.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
2^{64}. Implementors are advised to use algorithms whose period
is at least 2^{191}.
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 RandomGenerator.JumpableGenerator
interface but need not also
implement the RandomGenerator.LeapableGenerator
interface. A typical strategy for
a multithreaded application is to create a single
RandomGenerator.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 RandomGenerator.LeapableGenerator
are typically not
cryptographically secure. Consider instead using SecureRandom
to
get a cryptographically secure pseudorandom number generator for use by
securitysensitive 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 TypeMethodDescriptioncopy()
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).Copy this generator, leap this generator forward, then return the copy.void
leap()
Alter the state of this pseudorandom number generator so as to leap forward a large, fixed distance (typically 2^{96} or more) within its state cycle.double
Returns the distance by which theleap
() 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 theRandomGenerator.JumpableGenerator
interface.default Stream
<RandomGenerator.JumpableGenerator> leaps
(long streamSize) Returns a stream producing the givenstreamSize
number of new pseudorandom number generators, each of which implements theRandomGenerator.JumpableGenerator
interface.Methods declared in interface java.util.random.RandomGenerator
doubles, doubles, doubles, doubles, 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
Methods declared in interface java.util.random.RandomGenerator.JumpableGenerator
copyAndJump, jump, jumpDistance, jumps, jumps, rngs, rngs

Method Details

of
 Parameters:
name
 Name of random number generator algorithm Returns:
 An instance of
RandomGenerator.LeapableGenerator
 Throws:
NullPointerException
 if name is nullIllegalArgumentException
 if the named algorithm is not found

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). Specified by:
copy
in interfaceRandomGenerator.JumpableGenerator
 Returns:
 a new object that is a copy of this generator

leap
void leap()Alter the state of this pseudorandom number generator so as to leap forward a large, fixed distance (typically 2^{96} or more) within its state cycle. 
leapDistance
double leapDistance()Returns the distance by which theleap
() method will leap forward within the state cycle of this generator object. Returns:
 the default leap distance (as a
double
value)

leaps
Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements theRandomGenerator.JumpableGenerator
interface. Implementation Requirements:
 The default implementation produces a sequential stream that repeatedly
calls
copy
() andleap
() on this generator, and the copies become the generators produced by the stream.  Implementation Note:
 It is permitted to implement this method in a manner equivalent to
leaps
(Long.MAX_VALUE
).  Returns:
 a stream of objects that implement the
RandomGenerator.JumpableGenerator
interface

leaps
Returns a stream producing the givenstreamSize
number of new pseudorandom number generators, each of which implements theRandomGenerator.JumpableGenerator
interface. Implementation Requirements:
 The default implementation produces a sequential stream that repeatedly
calls
copy
() andleap
() on this generator, and the copies become the generators produced by the stream.  Parameters:
streamSize
 the number of generators to generate Returns:
 a stream of objects that implement the
RandomGenerator.JumpableGenerator
interface  Throws:
IllegalArgumentException
 ifstreamSize
is less than zero

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:
 a copy of this generator object before the leap occurred
