com.goldencode.util

Class RandomWordGenerator

java.lang.Object

com.goldencode.util.RandomWordGenerator

public final class RandomWordGenerator
extends java.lang.Object

Simple helper to create a random word, suitable for use as a password or other security token.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GEN_DIGITS Default random generator digits
static int	GEN_LENGTH Default random generator length.
static int	GEN_SYMBOLS Default random generator symbols
private static CentralLogger	LOG Logger

Constructor Summary

Constructors

Constructor and Description
RandomWordGenerator()

Method Summary

Modifier and Type	Method and Description
static java.lang.String	create() Create a pseudorandom word using the default length, number of digits and symbol characters.
static java.lang.String	create(int length, int digits, int symbols) Create a pseudorandom word of the specified length, containing the specified number of digit and symbol characters.
private static void	fillRandomSlots(char[] buffer, int number, java.lang.String pool) Using characters from the specified pool, randomly chosen, fill randomly chosen elements in the given character buffer.
static void	main(java.lang.String[] args) Command line entry point to this class.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final CentralLogger LOG

Logger

GEN_LENGTH

public static final int GEN_LENGTH

Default random generator length.

See Also:

Constant Field Values

GEN_DIGITS

public static final int GEN_DIGITS

Default random generator digits

See Also:

Constant Field Values

GEN_SYMBOLS

public static final int GEN_SYMBOLS

Default random generator symbols

See Also:

Constant Field Values

Constructor Detail

RandomWordGenerator

public RandomWordGenerator()

Method Detail

create

public static java.lang.String create()

Create a pseudorandom word using the default length, number of digits and symbol characters. The remaining characters, if any, will be alphabetical (random mix of upper and lower case).

Returns:

A pseudorandom word or empty string.

Throws:

java.lang.IllegalArgumentException - if the specified number of digits and symbols combined exceeds the specified length.

create

public static java.lang.String create(int length,
                                      int digits,
                                      int symbols)

Create a pseudorandom word of the specified length, containing the specified number of digit and symbol characters. The remaining characters, if any, will be alphabetical (random mix of upper and lower case).

Parameters:

length - Length of the word; must be nonnegative and greater than or equal to the sum of digits and symbols.

digits - Number of digit characters required; will be ignored if less than 0.

symbols - Number of symbol characters required; will be ignored if less than 0.

Returns:

A pseudorandom word or empty string.

Throws:

java.lang.IllegalArgumentException - if the specified number of digits and symbols combined exceeds the specified length.

fillRandomSlots

private static void fillRandomSlots(char[] buffer,
                                    int number,
                                    java.lang.String pool)

Using characters from the specified pool, randomly chosen, fill randomly chosen elements in the given character buffer.

Implementation note: this algorithm is biased toward shorter words (i.e., tens to hundreds of characters). Performance degrades non-linearly with larger word lengths.

Parameters:

buffer - Buffer to populate.

number - Number of fill characters to generate.

pool - Pool of potential candidate characters from which to choose.

Throws:

java.lang.IllegalArgumentException - if number exceeds the buffer length.

main

public static void main(java.lang.String[] args)

Command line entry point to this class.

Parameters:

args -

1. length - length of word to be generated
2. digits - number of digit characters to include in word
3. symbols - number of symbol characters to include in word