oracle.adfnmc.java.util
Class Random

java.lang.Object
  oracle.adfnmc.java.util.Random

All Implemented Interfaces:

Serializable

public class Random
extends java.lang.Object
implements Serializable

This class provides methods that generates pseudo-random numbers of different types, such as int, long, double and float using either

See Also:

Properties, PropertyResourceBundle

Constructor Summary

Random()
Construct a random generator with the current time of day in milliseconds as the initial state.

Random(long seed)
Construct a random generator with the given seed as the initial state.

Method Summary

protected int	next(int bits) Returns a pseudo-random uniformly distributed int value of the number of bits specified by the argument bits.
boolean	nextBoolean() Answers the next pseudo-random, uniformly distributed boolean value generated by this generator.
void	nextBytes(byte[] buf) Modifies the byte array by a random sequence of bytes generated by this random number generator.
double	nextDouble() Generates a normally distributed random double number between 0.0 inclusively and 1.0 exclusively.
float	nextFloat() Generates a normally distributed random float number between 0.0 inclusively and 1.0 exclusively.
double	nextGaussian() Returns a pseudo-randomly generated, normally distributed double value with mean 0.0 and a standard deviation value of 1.0.
int	nextInt() Generates a uniformly distributed 32-bit int value from the this random number sequence.
int	nextInt(int n) Returns a new pseudo-random integer value which is uniformly distributed between 0 (inclusively) and n (exclusively).
long	nextLong() Generates a uniformly distributed 64-bit int value from the this random number sequence.
void	setSeed(long seed) Modifies the seed using a linear congruential formula, as found in The Art of Computer Programming, Volume 2, by Donald E.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Random

public Random()

Construct a random generator with the current time of day in milliseconds as the initial state.

See Also:

setSeed(long)

Random

public Random(long seed)

Construct a random generator with the given seed as the initial state.

Parameters:

seed - the seed that will determine the initial state of this random number generator

See Also:

setSeed(long)

Method Detail

next

protected int next(int bits)

Returns a pseudo-random uniformly distributed int value of the number of bits specified by the argument bits. Implements D. H. Lehmer's random number algorithm found in The Art of Computer Programming, Volume 2: Seminumerical Algorithms, by Donald E. Knuth (section 3.2.1).

Parameters:

bits - number of bits of the returned value

Returns:

a pseudo-randomly generated int

See Also:

nextBytes(byte[]), nextDouble(), nextFloat(), nextInt(), nextInt(int), nextGaussian(), nextLong()

nextBoolean

public boolean nextBoolean()

Answers the next pseudo-random, uniformly distributed boolean value generated by this generator.

Returns:

boolean a pseudo-random, uniformly distributed boolean value

nextBytes

public void nextBytes(byte[] buf)

Modifies the byte array by a random sequence of bytes generated by this random number generator.

Parameters:

buf - non-null array to contain the new random bytes

See Also:

next(int)

nextDouble

public double nextDouble()

Generates a normally distributed random double number between 0.0 inclusively and 1.0 exclusively.

Returns:

a random double between 0.0 and 1.0

See Also:

nextFloat()

nextFloat

public float nextFloat()

Generates a normally distributed random float number between 0.0 inclusively and 1.0 exclusively.

Returns:

a random float between 0.0 and 1.0

See Also:

nextDouble()

nextGaussian

public double nextGaussian()

Returns a pseudo-randomly generated, normally distributed double value with mean 0.0 and a standard deviation value of 1.0. Implements G. E. P. Box, M. E. Muller, and G. Marsaglia's polar method found in The Art of Computer Programming, Volume 2: Seminumerical Algorithms, by Donald E. Knuth (section 3.4.1).

Returns:

a pseudo-randomly generated double

See Also:

nextDouble()

nextInt

public int nextInt()

Generates a uniformly distributed 32-bit int value from the this random number sequence.

Returns:

a randomly generated int

See Also:

Integer.MAX_VALUE, Integer.MIN_VALUE, next(int), nextLong()

nextInt

public int nextInt(int n)

Returns a new pseudo-random integer value which is uniformly distributed between 0 (inclusively) and n (exclusively).

Parameters:

n - the upper limit of the values that can be returned

Returns:

a randomly generated int between 0 and n

nextLong

public long nextLong()

Generates a uniformly distributed 64-bit int value from the this random number sequence.

Returns:

64-bit int random number

See Also:

Integer.MAX_VALUE, Integer.MIN_VALUE, next(int), nextInt(), nextInt(int)

setSeed

public void setSeed(long seed)

Modifies the seed using a linear congruential formula, as found in The Art of Computer Programming, Volume 2, by Donald E. Knuth (section 3.2.1).

Parameters:

seed - the seed that alters the state of the random number generator

See Also:

next(int), Random(), Random(long)