Password Generator

The Password Generator is a Java library designed to create random passwords with flexible rules and customization options. It allows you to specify the length of the password, set length ranges, and define the percentage distribution of character types (upper case, lower case, numbers, and special characters). The library also allows the inclusion and exclusion of selected characters.

Getting Started

To get started, create an instance of the PasswordGenerator.

PasswordGenerator password = new PasswordGenerator();

Password Length

You can set the exact length of the password or define a range. By default, password length is set to 30.

password.setLength(27); // Set exact length of password
password.setRange(20, 30); // Set password length range

Character Type Distribution

You can specify the percentage distribution for each character type (upper, lower, number, special), using integers or decimals. Integers must add up to 100 and decimals to 1.0. By default, the password distribution is set at 25% for each type.

password.setConstantShare(30, 15, 30, 15); // 30% upper, 15% lower, 30% number, 15% special
password.setConstantShare(0.3, 0.15, 0.3, 0.15); // Same as above using decimals

You can also set absolute random distribution or distribution with minimum values for each case type. As with setting the regular distribution integers and decimals parameters can also be used.

password.setRandomShare(); // Absolute random usage between character types 
password.setRandomShare(10); // Random with minimum value of 10% for each type
password.setRandomShare(20, 20, 20, 20); // Random with minimum value (20%) usage for each type

Including and Excluding Characters

You can include or exclude specific characters in all groups (upper, lower, number, special). The include() method adds characters or character arrays to the character sets used for generating passwords, while the exclude() method removes characters or character arrays from these sets.

Include examples

char[] array = {'x', 'y', 'z'}; // Sample array
password.include(' '); // Automatically include space character in "special" set
password.include('1', "upper"); // Append '1' to "upper" type set
password.include('X', "lower", true); // Allow duplicates in the "lower" set
password.include(array); // Automatically appends array (in that case to "lower" set)

Exclude examples

char[] array = {'&', '^', '~'}; // Sample array
password.exclude(' '); // Exclude space character from "special" set
password.exclude('3', "number"); // Delete '3' from "number" type set
password.exclude('X', "special", true); // Allow ignoring non-existent characters 
password.exclude(array); // Automatically delete provided characters (in that case from "special" set)

Method arguments that can be used interchangeably:

Original	Equivalent
"upper"	1
"lower"	2
"number"	3
"special"	4

Generating Password

To generate a password based on the defined rules, you must assign the result to a variable of type String as shown below. The full source code for the basic password generation program can be found in the src/Main.java file.

String samplePassword = password.generate();

Retrieving Information

For password generating rules length() and range() must be assigned to variables. Other methods print values to the console. In showCaseCollection("\n") it is necessary to specify a character to separate groups of characters.

int length = password.length(); // Return length rule of current password
int[] range = password.range(); // Return range rule of current password
password.showCaseCollection("\t"); // Print characters collection
password.showRules(); // Prints character distribution

Default Rules and Collections

If you want to return to the default setting for character length and distribution you can by using setDefaultRules();. For default characters you can apply setDefaultCollection();.This method retrieves the basis values from the ASCII table.

password.setDefaultRules(); // Default length and character type distribution
password.setDefaultCollection(); // Default collections (upper, lower, number special)