- All Superinterfaces:
- RandomGenerator,- RandomGenerator.StreamableGenerator
- All Known Subinterfaces:
- RandomGenerator.ArbitrarilyJumpableGenerator,- RandomGenerator.LeapableGenerator
- Enclosing interface:
- RandomGenerator
 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.
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Nested Class SummaryNested classes/interfaces declared in interface java.util.random.RandomGeneratorRandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator
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Method SummaryModifier 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).default RandomGeneratorCopy this generator, jump this generator forward, then return the copy.voidjump()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.doubleReturns the distance by which thejump() method will jump forward within the state cycle of this generator object.default Stream<RandomGenerator> jumps()Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.default Stream<RandomGenerator> jumps(long streamSize) Returns a stream producing the givenstreamSizenumber of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.default Stream<RandomGenerator> rngs()Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.default Stream<RandomGenerator> rngs(long streamSize) Returns a stream producing the givenstreamSizenumber of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.Methods declared in interface java.util.random.RandomGeneratordoubles, 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
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Method Details- 
of- Parameters:
- name- Name of random number generator algorithm
- Returns:
- An instance of RandomGenerator.JumpableGenerator
- Throws:
- NullPointerException- if name is null
- IllegalArgumentException- if the named algorithm is not found
 
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copyReturns 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:
- a new object that is a copy of this generator
 
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jumpvoid 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.
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jumpDistancedouble jumpDistance()Returns the distance by which thejump() method will jump forward within the state cycle of this generator object.- Returns:
- the default jump distance (as a doublevalue)
 
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jumpsReturns an effectively unlimited stream of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.- Implementation Requirements:
- The default implementation produces a sequential stream that  repeatedly
 calls copy() andjump() 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
 jumps(Long.MAX_VALUE).
- Returns:
- a stream of objects that implement the RandomGeneratorinterface
 
- 
jumpsReturns a stream producing the givenstreamSizenumber of new pseudorandom number generators, each of which implements theRandomGeneratorinterface.- Implementation Requirements:
- The default implementation produces a sequential stream that  repeatedly
 calls copy() andjump() 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 RandomGeneratorinterface
- Throws:
- IllegalArgumentException- if- streamSizeis less than zero
 
- 
rngsReturns an effectively unlimited stream of new pseudorandom number generators, each of which implements theRandomGeneratorinterface. Ideally the generators in the stream will appear to be statistically independent.- Specified by:
- rngsin interface- RandomGenerator.StreamableGenerator
- Implementation Requirements:
- The default implementation calls jumps().
- Returns:
- a stream of objects that implement the RandomGeneratorinterface
 
- 
rngsReturns a stream producing the givenstreamSizenumber of new pseudorandom number generators, each of which implements theRandomGeneratorinterface. Ideally the generators in the stream will appear to be statistically independent.- Specified by:
- rngsin interface- RandomGenerator.StreamableGenerator
- Implementation Requirements:
- The default implementation calls jumps(streamSize).
- Parameters:
- streamSize- the number of generators to generate
- Returns:
- a stream of objects that implement the RandomGeneratorinterface
- Throws:
- IllegalArgumentException- if- streamSizeis less than zero
 
- 
copyAndJumpCopy this generator, jump this generator forward, then return the copy.- Implementation Requirements:
- The default implementation copies this, jumps and then returns the copy.
- Returns:
- a copy of this generator object before the jump occurred
 
 
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