java.util.Random
This class provides methods that generates pseudo-random numbers of different
types, such as int, long, double and float using either
Known Direct Subclasses
Summary
Public Constructors
Public Methods
Protected Methods
|
synchronized |
|
|
|
int |
next(int bits) |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait
Details
Public Constructors
public
Random()
Construct a random generator with the current time of day in milliseconds
as the initial state.
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 |
Public Methods
public
boolean
nextBoolean()
Returns the next pseudo-random, uniformly distributed boolean value
generated by this generator.
Returns
- boolean a pseudo-random, uniformly distributed boolean value
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 |
public
double
nextDouble()
Generates a normally distributed random double number between 0.0
inclusively and 1.0 exclusively.
public
float
nextFloat()
Generates a normally distributed random float number between 0.0
inclusively and 1.0 exclusively.
Returns
- float a random float number between 0.0 and 1.0
public
synchronized
double
nextGaussian()
pseudo-randomly generates (approximately) a normally distributed
double
value with mean 0.0 and a standard deviation value
of
1.0
using the
polar method of G. E. P. Box, M.
E. Muller, and G. Marsaglia, as described by Donald E. Knuth in The
Art of Computer Programming, Volume 2: Seminumerical Algorithms,
section 3.4.1, subsection C, algorithm P
public
int
nextInt(int n)
Returns to the caller a new pseudo-random integer value which is uniformly
distributed between 0 (inclusively) and the value of
n
(exclusively).
public
int
nextInt()
Generates a uniformly distributed 32-bit
int
value from
the this random number sequence.
Returns
- int uniformly distributed
int
value
public
long
nextLong()
Generates a uniformly distributed 64-bit
int
value from
the this random number sequence.
public
synchronized
void
setSeed(long seed)
Modifies the seed using linear congruential formula presented in
The
Art of Computer Programming, Volume 2, Section 3.2.1.
Parameters
seed
| the seed that alters the state of the random number generator |
Protected Methods
protected
synchronized
int
next(int bits)
Returns a pseudo-random uniformly distributed
int
value of
the number of bits specified by the argument
bits
as
described by Donald E. Knuth in
The Art of Computer Programming,
Volume 2: Seminumerical Algorithms, section 3.2.1.
Parameters
bits
| number of bits of the returned value |
Returns
- int a pseudo-random generated int number