RandomGenerator
, RandomGenerator.StreamableGenerator
RandomGenerator.ArbitrarilyJumpableGenerator
, RandomGenerator.LeapableGenerator
RandomGenerator
public static interface RandomGenerator.JumpableGenerator extends RandomGenerator.StreamableGenerator
Ideally, all RandomGenerator.JumpableGenerator
objects produced by iterative jumping from a single original RandomGenerator.JumpableGenerator
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 jump()
method is used to produce a number of values no larger than either 264 or the square root of its period. Implementors are advised to use algorithms whose period is at least 2127.
Methods are provided to perform a single jump operation and also to produce a stream of generators produced from the original by iterative copying and jumping of internal state. A typical strategy for a multithreaded application is to create a single RandomGenerator.JumpableGenerator
object, calls its jump
() method exactly once, and then parcel out generators from the resulting stream, one to each thread. It is generally not a good idea to call jump
() on a generator that was itself produced by the jump
() method, because the result may be a generator identical to another generator already produce by that call to the jump
() method. For this reason, the return type of the jumps
() method is Stream<RandomGenerator>
rather than Stream<RandomGenerator.JumpableGenerator>
, even though the actual generator objects in that stream likely do also implement the RandomGenerator.JumpableGenerator
interface.
Objects that implement RandomGenerator.JumpableGenerator
are typically not cryptographically secure. Consider instead using SecureRandom
to get a cryptographically secure pseudo-random number generator for use by security-sensitive applications.
RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator
Modifier and Type | Method | Description |
---|---|---|
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. |
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. |
double |
jumpDistance() |
Returns the distance by which the jump () method will jump forward within the state cycle of this generator object. |
default Stream |
jumps() |
Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator interface. |
default Stream |
jumps |
Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator interface. |
static RandomGenerator.JumpableGenerator |
of |
|
default Stream |
rngs() |
Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator interface. |
default Stream |
rngs |
Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator interface. |
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
static RandomGenerator.JumpableGenerator of(String name)
name
- Name of random number generator algorithm
RandomGenerator.JumpableGenerator
NullPointerException
- if name is nullIllegalArgumentException
- if the named algorithm is not foundRandomGenerator.JumpableGenerator copy()
void jump()
double jumpDistance()
jump
() method will jump forward within the state cycle of this generator object.double
value)default Stream<RandomGenerator> jumps()
RandomGenerator
interface.copy
() and jump
() on this generator, and the copies become the generators produced by the stream.jumps
(Long.MAX_VALUE
).RandomGenerator
interfacedefault Stream<RandomGenerator> jumps(long streamSize)
streamSize
number of new pseudorandom number generators, each of which implements the RandomGenerator
interface.copy
() and jump
() on this generator, and the copies become the generators produced by the stream.streamSize
- the number of generators to generateRandomGenerator
interfaceIllegalArgumentException
- if streamSize
is less than zerodefault Stream<RandomGenerator> rngs()
RandomGenerator
interface. Ideally the generators in the stream will appear to be statistically independent.rngs
in interface RandomGenerator.StreamableGenerator
jumps
().RandomGenerator
interfacedefault Stream<RandomGenerator> rngs(long streamSize)
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.rngs
in interface RandomGenerator.StreamableGenerator
jumps
(streamSize).streamSize
- the number of generators to generateRandomGenerator
interfaceIllegalArgumentException
- if streamSize
is less than zerodefault RandomGenerator copyAndJump()
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/random/RandomGenerator.JumpableGenerator.html