Java in a Nutshell, 5th Edition [Electronic resources]

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Randomjava.util

Java 1.0serializable

This class implements a pseudorandom number generator suitable for games and similar applications. If you need a cryptographic-strength source of pseudorandomness, see java.security.SecureRandom. nextdouble( ) and nextFloat( ) return a value between 0.0 and 1.0. nextLong( ) and the no-argument version of nextInt( ) return long and int values distributed across the range of those data types. As of Java 1.2, if you pass an argument to nextInt( ), it returns a value between zero (inclusive) and the specified number (exclusive). nextGaussian( ) returns pseudorandom floating-point values with a Gaussian distribution; the mean of the values is 0.0 and the standard deviation is 1.0. nextBoolean( ) returns a pseudorandom boolean value, and nextBytes( ) fills in the specified byte array with pseudorandom bytes. You can use the setSeed( ) method or the optional constructor argument to initialize the pseudorandom number generator with some variable seed value other than the current time (the default) or with a constant to ensure a repeatable sequence of pseudorandomness.

Figure 16-52. java.util.Random

public class

Random implements Serializable { // Public Constructors public

Random ( ); public

Random (long

seed ); // Public Instance Methods

1.2 public boolean

nextBoolean ( );

1.1 public void

nextBytes (byte[ ]

bytes ); public double

nextDouble ( ); public float

nextFloat ( ); public double

nextGaussian ( ); synchronized public int

nextInt ( );

1.2 public int

nextInt (int

n ); public long

nextLong ( ); public void

setSeed (long

seed ); synchronized // Protected Instance Methods

1.1 protected int

next (int

bits ); }

Subclasses

java.security.SecureRandom

Passed To

java.math.BigInteger.{BigInteger( ), probablePrime( )}, Collections.shuffle( )