RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator
Random, SecureRandom, SplittableRandom, ThreadLocalRandom
public interface RandomGenerator
The
RandomGenerator
interface is designed to provide a common protocol for objects that generate random or (more typically) pseudorandom sequences of numbers (or Boolean values). Such a sequence may be obtained by either repeatedly invoking a method that returns a single pseudorandomly chosen value, or by invoking a method that returns a stream of pseudorandomly chosen values.
Ideally, given an implicitly or explicitly specified range of values, each value would be chosen independently and uniformly from that range. In practice, one may have to settle for some approximation to independence and uniformity.
In the case of int, long, and boolean values, if there is no explicit specification of range, then the range includes all possible values of the type. In the case of float and double values, first a value is always chosen uniformly from the set of 2w values between 0.0 (inclusive) and 1.0 (exclusive), where w is Float.PRECISION for float values and Double.PRECISION for double values, such that adjacent values differ by 2−w (notice that this set is a subset of the set of all representable floating-point values between 0.0 (inclusive) and 1.0 (exclusive)); then if an explicit range was specified, then the chosen number is computationally scaled and translated so as to appear to have been chosen approximately uniformly from that explicit range.
Each method that returns a stream produces a stream of values each of which is chosen in the same manner as for a method that returns a single pseudorandomly chosen value. For example, if r implements RandomGenerator, then the method call r.ints(100) returns a stream of 100 int values. These are not necessarily the exact same values that would have been returned if instead r.nextInt() had been called 100 times; all that is guaranteed is that each value in the stream is chosen in a similar pseudorandom manner from the same range.
Every object that implements the RandomGenerator interface by using a pseudorandom algorithm is assumed to contain a finite amount of state. Using such an object to generate a pseudorandomly chosen value alters its state by computing a new state as a function of the current state, without reference to any information other than the current state. The number of distinct possible states of such an object is called its period. (Some implementations of the RandomGenerator interface may be truly random rather than pseudorandom, for example relying on the statistical behavior of a physical object to derive chosen values. Such implementations do not have a fixed period.)
As a rule, objects that implement the RandomGenerator interface need not be thread-safe. It is recommended that multithreaded applications use either ThreadLocalRandom or (preferably) pseudorandom number generators that implement the RandomGenerator.SplittableGenerator or RandomGenerator.JumpableGenerator interface.
Objects that implement RandomGenerator are typically not cryptographically secure. Consider instead using SecureRandom to get a cryptographically secure pseudorandom number generator for use by security-sensitive applications. Note, however, that SecureRandom does implement the RandomGenerator interface, so that instances of SecureRandom may be used interchangeably with other types of pseudorandom generators in applications that do not require a secure generator.
Unless explicit stated otherwise, the use of null for any method argument will cause a NullPointerException.
Nested Classes
static interface
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.
static interface
This interface is designed to provide a common protocol for objects that generate pseudorandom values and can easily jump forward, by a moderate amount (ex. 264) to a distant point in the state cycle.
static interface
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.
static interface
This interface is designed to provide a common protocol for objects that generate sequences of pseudorandom values and can be split into two objects (the original one and a new one) each of which obey that same protocol (and therefore can be recursively split indefinitely).
static interface
Returns an effectively unlimited stream of pseudorandomly chosen double values.
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).
Returns a stream producing the given streamSize number of pseudorandomly chosen double values.
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).
Returns a
RandomGenerator
meeting the minimal requirement of having an
algorithmwhose state bits are greater than or equal 64.
Returns an effectively unlimited stream of pseudorandomly chosen int values.
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).
Returns a stream producing the given streamSize number of pseudorandomly chosen int values.
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
Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
Returns an effectively unlimited stream of pseudorandomly chosen long values.
Returns a stream producing the given streamSize number of pseudorandomly chosen long values.
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).
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
Returns a pseudorandomly chosen boolean value.
default void
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
Returns a pseudorandom double value between zero (inclusive) and one (exclusive).
default double
Returns a pseudorandomly chosen double value between zero (inclusive) and the specified bound (exclusive).
default double
Returns a pseudorandomly chosen double value between the specified origin (inclusive) and the specified bound (exclusive).
default double
Returns a nonnegative double value pseudorandomly chosen from an exponential distribution whose mean is 1.
default float
Returns a pseudorandom float value between zero (inclusive) and one (exclusive).
default float
Returns a pseudorandomly chosen float value between zero (inclusive) and the specified bound (exclusive).
default float
Returns a pseudorandomly chosen float value between the specified origin (inclusive) and the specified bound (exclusive).
default double
Returns a double value pseudorandomly chosen from a Gaussian (normal) distribution whose mean is 0 and whose standard deviation is 1.
default double
Returns a double value pseudorandomly chosen from a Gaussian (normal) distribution with a mean and standard deviation specified by the arguments.
default int
Returns a pseudorandomly chosen int value.
default int
Returns a pseudorandomly chosen int value between zero (inclusive) and the specified bound (exclusive).
default int
Returns a pseudorandomly chosen int value between the specified origin (inclusive) and the specified bound (exclusive).
long
Returns a pseudorandomly chosen long value.
default long
Returns a pseudorandomly chosen long value between zero (inclusive) and the specified bound (exclusive).
default long
Returns a pseudorandomly chosen long value between the specified origin (inclusive) and the specified bound (exclusive).
name - Name of random number generator algorithm
RandomGenerator
NullPointerException - if name is null
IllegalArgumentException - if the named algorithm is not found
Returns a
RandomGenerator
meeting the minimal requirement of having an
algorithmwhose state bits are greater than or equal 64.
The default implementation selects L32X64MixRandom.
RandomGenerator
default boolean isDeprecated()
Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
Returns an effectively unlimited stream of pseudorandomly chosen double values.
nextDouble().
doubles (Long.MAX_VALUE).
double values
Returns an effectively unlimited stream of pseudorandomly chosen double values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
nextDouble(randomNumberOrigin, randomNumberBound).
doubles (Long.MAX_VALUE, randomNumberOrigin, randomNumberBound).
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
double values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if randomNumberOrigin is not finite, or randomNumberBound is not finite, or randomNumberOrigin is greater than or equal to randomNumberBound
Returns a stream producing the given streamSize number of pseudorandomly chosen double values.
nextDouble().
streamSize - the number of values to generate
double values
IllegalArgumentException - if streamSize is less than zero
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).
nextDouble(randomNumberOrigin, randomNumberBound).
streamSize - the number of values to generate
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
double values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if streamSize is less than zero, or randomNumberOrigin is not finite, or randomNumberBound is not finite, or randomNumberOrigin is greater than or equal to randomNumberBound
Returns an effectively unlimited stream of pseudorandomly chosen int values.
nextInt().
ints (Long.MAX_VALUE).
int values
Returns an effectively unlimited stream of pseudorandomly chosen int values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
nextInt(randomNumberOrigin, randomNumberBound).
ints (Long.MAX_VALUE, randomNumberOrigin, randomNumberBound).
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
int values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if randomNumberOrigin is greater than or equal to randomNumberBound
Returns a stream producing the given streamSize number of pseudorandomly chosen int values.
nextInt().
streamSize - the number of values to generate
int values
IllegalArgumentException - if streamSize is less than zero
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).
nextInt(randomNumberOrigin, randomNumberBound).
streamSize - the number of values to generate
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
int values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if streamSize is less than zero, or randomNumberOrigin is greater than or equal to randomNumberBound
Returns an effectively unlimited stream of pseudorandomly chosen long values.
nextLong().
longs (Long.MAX_VALUE).
long values
Returns an effectively unlimited stream of pseudorandomly chosen long values, where each value is between the specified origin (inclusive) and the specified bound (exclusive).
nextLong(randomNumberOrigin, randomNumberBound).
longs (Long.MAX_VALUE, randomNumberOrigin, randomNumberBound).
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
long values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if randomNumberOrigin is greater than or equal to randomNumberBound
Returns a stream producing the given streamSize number of pseudorandomly chosen long values.
nextLong().
streamSize - the number of values to generate
long values
IllegalArgumentException - if streamSize is less than zero
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).
nextLong(randomNumberOrigin, randomNumberBound).
streamSize - the number of values to generate
randomNumberOrigin - the least value that can be produced
randomNumberBound - the upper bound (exclusive) for each value produced
long values, each between the specified origin (inclusive) and the specified bound (exclusive)
IllegalArgumentException - if streamSize is less than zero, or randomNumberOrigin is greater than or equal to randomNumberBound
default boolean nextBoolean()
Returns a pseudorandomly chosen
boolean
value.
The default implementation tests the high-order bit (sign bit) of a value produced by nextInt(), on the grounds that some algorithms for pseudorandom number generation produce values whose high-order bits have better statistical quality than the low-order bits.
nextInt().
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).
nextLong().
void nextBytes(byte[] bytes) {
int i = 0;
int len = bytes.length;
for (int words = len >> 3; words--> 0; ) {
long rnd = nextLong();
for (int n = 8; n--> 0; rnd >>>= Byte.SIZE)
bytes[i++] = (byte)rnd;
}
if (i < len)
for (long rnd = nextLong(); i < len; rnd >>>= Byte.SIZE)
bytes[i++] = (byte)rnd;
}bytes - the byte array to fill with pseudorandom bytes
NullPointerException - if bytes is null
default float nextFloat()
Returns a pseudorandom float value between zero (inclusive) and one (exclusive).
Float.PRECISION high-order bits from a call to nextInt().
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).
bound is a positive finite float. Then invokes nextFloat(), scaling the result so that the final result lies between 0.0f (inclusive) and bound (exclusive).
bound - the upper bound (exclusive) for the returned value. Must be positive and finite
float value between zero (inclusive) and the bound (exclusive)
IllegalArgumentException - if bound is not both positive and finite
default float nextFloat(float origin, float bound)
Returns a pseudorandomly chosen float value between the specified origin (inclusive) and the specified bound (exclusive).
origin and bound are valid then invokes nextFloat() scaling and translating the result to fit between origin and bound (exclusive).
origin - the least value that can be returned
bound - the upper bound (exclusive)
float value between the origin (inclusive) and the bound (exclusive)
IllegalArgumentException - if origin is not finite, or bound is not finite, or origin is greater than or equal to bound
default double nextDouble()
Returns a pseudorandom double value between zero (inclusive) and one (exclusive).
Double.PRECISION high-order bits from a call to nextLong().
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).
bound is a positive finite double. Then invokes nextDouble(), scaling the result so that the final result lies between 0.0 (inclusive) and bound (exclusive).
bound - the upper bound (exclusive) for the returned value. Must be positive and finite
double value between zero (inclusive) and the bound (exclusive)
IllegalArgumentException - if bound is not both positive and finite
default double nextDouble(double origin, double bound)
Returns a pseudorandomly chosen double value between the specified origin (inclusive) and the specified bound (exclusive).
origin and bound are valid, then invokes nextDouble() scaling and translating the result to fit between origin and bound( exclusive).
origin - the least value that can be returned
bound - the upper bound (exclusive) for the returned value
double value between the origin (inclusive) and the bound (exclusive)
IllegalArgumentException - if origin is not finite, or bound is not finite, or origin is greater than or equal to bound
default int nextInt()
Returns a pseudorandomly chosen int value.
nextLong().
int value
default int nextInt(int bound)
Returns a pseudorandomly chosen int value between zero (inclusive) and the specified bound (exclusive).
bound is a positive int. Then invokes nextInt(), limiting the result to be greater than or equal zero and less than bound. If bound is a power of two then limiting is a simple masking operation. Otherwise, the result is re-calculated by invoking nextInt() until the result is greater than or equal zero and less than bound.
bound - the upper bound (exclusive) for the returned value. Must be positive.
int value between zero (inclusive) and the bound (exclusive)
IllegalArgumentException - if bound is not positive
default int nextInt(int origin, int bound)
Returns a pseudorandomly chosen int value between the specified origin (inclusive) and the specified bound (exclusive).
origin and bound are positive ints. Then invokes nextInt(), limiting the result to be greater that or equal origin and less than bound. If bound is a power of two then limiting is a simple masking operation. Otherwise, the result is re-calculated by invoking nextInt() until the result is greater than or equal origin and less than bound.
origin - the least value that can be returned
bound - the upper bound (exclusive) for the returned value
int value between the origin (inclusive) and the bound (exclusive)
IllegalArgumentException - if origin is greater than or equal to bound
long nextLong()
Returns a pseudorandomly chosen long value.
long value
default long nextLong(long bound)
Returns a pseudorandomly chosen long value between zero (inclusive) and the specified bound (exclusive).
bound is a positive long. Then invokes nextLong(), limiting the result to be greater than or equal zero and less than bound. If bound is a power of two then limiting is a simple masking operation. Otherwise, the result is re-calculated by invoking nextLong() until the result is greater than or equal zero and less than bound.
bound - the upper bound (exclusive) for the returned value. Must be positive.
long value between zero (inclusive) and the bound (exclusive)
IllegalArgumentException - if bound is not positive
default long nextLong(long origin, long bound)
Returns a pseudorandomly chosen long value between the specified origin (inclusive) and the specified bound (exclusive).
origin and bound are positive longs. Then invokes nextLong(), limiting the result to be greater than or equal origin and less than bound. If bound is a power of two then limiting is a simple masking operation. Otherwise, the result is re-calculated by invoking nextLong() until the result is greater than or equal origin and less than bound.
origin - the least value that can be returned
bound - the upper bound (exclusive) for the returned value
long value between the origin (inclusive) and the bound (exclusive)
IllegalArgumentException - if origin is greater than or equal to bound
default double nextGaussian()
Returns a double value pseudorandomly chosen from a Gaussian (normal) distribution whose mean is 0 and whose standard deviation is 1.
double value pseudorandomly chosen from a Gaussian distribution
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.
mean - the mean of the Gaussian distribution to be drawn from
stddev - the standard deviation (square root of the variance) of the Gaussian distribution to be drawn from
double value pseudorandomly chosen from the specified Gaussian distribution
IllegalArgumentException - if stddev is negative
default double nextExponential()
Returns a nonnegative double value pseudorandomly chosen from an exponential distribution whose mean is 1.
double value pseudorandomly chosen from an exponential distribution
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4