Class java.util.Random 
All Packages    This Package    Previous    Next

Class java.util.Random 

java.lang.Object
   |
   +----java.util.Random
public class Random
extends Object
A Random class generates a stream of pseudo-random numbers.

To create a new random number generator, use one of the following methods: 

    new Random()       
    new Random(long seed)
The form new Random() initializes the generator to a value based on the current time. The form new Random(long seed) seeds the random number generator with a specific initial value; use this if an application requires a repeatable stream of pseudo-random numbers.

The random number generator uses a 48-bit seed, which is modified using a linear congruential formula. See Donald Knuth, The Art of Computer Programming, Volume 2, Section 3.2.1. The generator's seed can be reset with the following method: 

   setSeed(long seed)
To create a pseudo-random number, use one of the following functions: 
   nextInt()
   nextLong()
   nextFloat()
   nextDouble()
   nextGaussian()
See Also:
random
Version:
1.1, 27 Jul 1995
Author:
Frank Yellin

Constructor Index

o Random()
Creates a new random number generator.
o Random(long)
Creates a new random number generator using a single long seed.

Method Index

o nextDouble()
Generates a pseudorandom uniformally distributed double value between 0.0 and 1.0.
o nextFloat()
Generates a pseudorandom uniformally distributed float value between 0.0 and 1.0.
o nextGaussian()
Generates a pseudorandom Gaussian distributed double value with mean 0.0 and standard deviation 1.0.
o nextInt()
Generates a pseudorandom uniformally distributed int value.
o nextLong()
Generate a pseudorandom uniformally distributed long value.
o setSeed(long)
Sets the seed of the random number generator using a single long seed.

Constructors

o Random 
  public Random()
Creates a new random number generator. Its seed will be initialized to a value based on the current time.

o Random 

  public Random(long seed)
Creates a new random number generator using a single long seed.
Parameters:
seed - the initial seed
See Also:
setSeed

Methods

o setSeed 
  public synchronized void setSeed(long seed)
Sets the seed of the random number generator using a single long seed.
Parameters:
seed - the initial seed

o nextInt 

  public int nextInt()
Generates a pseudorandom uniformally distributed int value.
Returns:
an integer value.

o nextLong 

  public long nextLong()
Generate a pseudorandom uniformally distributed long value.
Returns:
A long integer value

o nextFloat 

  public float nextFloat()
Generates a pseudorandom uniformally distributed float value between 0.0 and 1.0.
Returns:
a float between 0.0 and 1.0 .

o nextDouble 

  public double nextDouble()
Generates a pseudorandom uniformally distributed double value between 0.0 and 1.0.
Returns:
a float between 0.0 and 1.0 .

o nextGaussian 

  public synchronized double nextGaussian()
Generates a pseudorandom Gaussian distributed double value with mean 0.0 and standard deviation 1.0.
Returns:
a Gaussian distributed double. 

All Packages    This Package    Previous    Next