IRandomGenerator Interface

Reference

Definition

Namespace:: Java.Util.RandomGenerators

Assembly:: Mono.Android.dll

Important

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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).

[Android.Runtime.Register("java/util/random/RandomGenerator", "", "Java.Util.RandomGenerators.IRandomGeneratorInvoker", ApiSince=35)]
public interface IRandomGenerator : Android.Runtime.IJavaObject, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("java/util/random/RandomGenerator", "", "Java.Util.RandomGenerators.IRandomGeneratorInvoker", ApiSince=35)>]
type IRandomGenerator = interface
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Derived: Java.Util.Random

Java.Util.SplittableRandom

Attributes: RegisterAttribute

Implements: IJavaObject IJavaPeerable IDisposable

Remarks

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 2<sup>w</sup> values between 0.0 (inclusive) and 1.0 (exclusive), where w is 23 for float values and 52 for double values, such that adjacent values differ by 2<sup>−w</sup> (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 SplittableGenerator or 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.

Added in 17.

Java documentation for java.util.random.RandomGenerator.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Properties

Default	Returns a `RandomGenerator` meeting the minimal requirement of having an algorithm whose state bits are greater than or equal 64.
Handle	Gets the JNI value of the underlying Android object. (Inherited from IJavaObject)
IsDeprecated	Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
JniIdentityHashCode	Returns the value of `java.lang.System.identityHashCode()` for the wrapped instance. (Inherited from IJavaPeerable)
JniManagedPeerState	State of the managed peer. (Inherited from IJavaPeerable)
JniPeerMembers	Member access and invocation support. (Inherited from IJavaPeerable)
PeerReference	Returns a JniObjectReference of the wrapped Java object instance. (Inherited from IJavaPeerable)

Methods

Disposed()	Called when the instance has been disposed. (Inherited from IJavaPeerable)
DisposeUnlessReferenced()	If there are no outstanding references to this instance, then calls `Dispose()`; otherwise, does nothing. (Inherited from IJavaPeerable)
Finalized()	Called when the instance has been finalized. (Inherited from IJavaPeerable)
NextBoolean()	Returns a pseudorandomly chosen `boolean` value.
NextBytes(Byte[])	Fills a user-supplied byte array with generated byte values pseudorandomly chosen uniformly from the range of values between -128 (inclusive) and 127 (inclusive).
NextDouble()	Returns a pseudorandom `double` value between zero (inclusive) and one (exclusive).
NextDouble(Double, Double)	Returns a pseudorandomly chosen `double` value between the specified origin (inclusive) and the specified bound (exclusive).
NextDouble(Double)	Returns a pseudorandomly chosen `double` value between zero (inclusive) and the specified bound (exclusive).
NextExponential()	Returns a nonnegative `double` value pseudorandomly chosen from an exponential distribution whose mean is 1.
NextFloat()	Returns a pseudorandom `float` value between zero (inclusive) and one (exclusive).
NextFloat(Single, Single)	Returns a pseudorandomly chosen `float` value between the specified origin (inclusive) and the specified bound (exclusive).
NextFloat(Single)	Returns a pseudorandomly chosen `float` value between zero (inclusive) and the specified bound (exclusive).
NextGaussian()	Returns a `double` value pseudorandomly chosen from a Gaussian (normal) distribution whose mean is 0 and whose standard deviation is 1.
NextGaussian(Double, Double)	Returns a `double` value pseudorandomly chosen from a Gaussian (normal) distribution with a mean and standard deviation specified by the arguments.
NextInt()	Returns a pseudorandomly chosen `int` value.
NextInt(Int32, Int32)	Returns a pseudorandomly chosen `int` value between the specified origin (inclusive) and the specified bound (exclusive).
NextInt(Int32)	Returns a pseudorandomly chosen `int` value between zero (inclusive) and the specified bound (exclusive).
NextLong()	Returns a pseudorandomly chosen `long` value.
NextLong(Int64, Int64)	Returns a pseudorandomly chosen `long` value between the specified origin (inclusive) and the specified bound (exclusive).
NextLong(Int64)	Returns a pseudorandomly chosen `long` value between zero (inclusive) and the specified bound (exclusive).
Of(String)	Returns an instance of `RandomGenerator` that utilizes the `name`algorithm.
SetJniIdentityHashCode(Int32)	Set the value returned by `JniIdentityHashCode`. (Inherited from IJavaPeerable)
SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from IJavaPeerable)
SetPeerReference(JniObjectReference)	Set the value returned by `PeerReference`. (Inherited from IJavaPeerable)
UnregisterFromRuntime()	Unregister this instance so that the runtime will not return it from future Java.Interop.JniRuntime+JniValueManager.PeekValue invocations. (Inherited from IJavaPeerable)

Extension Methods

JavaCast<TResult>(IJavaObject)	Performs an Android runtime-checked type conversion.
JavaCast<TResult>(IJavaObject)
GetJniTypeName(IJavaPeerable)	Gets the JNI name of the type of the instance `self`.
JavaAs<TResult>(IJavaPeerable)	Try to coerce `self` to type `TResult`, checking that the coercion is valid on the Java side.
TryJavaCast<TResult>(IJavaPeerable, TResult)	Try to coerce `self` to type `TResult`, checking that the coercion is valid on the Java side.

Applies to

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