RegRex – Java Builder for Regular Expressions

RegRex is a Java library that makes creating regular expressions easier. Instead of manually crafting complex regex strings, RegRex allows you to build expressions in a modular and readable way.

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🚀 Quick Start

import regrex.domain.RexRegEx;

public class Example {
    public static void main(String[] args) {
        RexRegEx builder = new RexRegEx();
        String regex = builder
        .followedFrom(RexRegEx.anyDigit())
        .followedFrom(RexRegEx.anyLetterFromSet("abc"))
        .getRegExString();

        System.out.println(regex); // Prints, for example, "\d[abc]"
    }
}

🔧 Functions

🔁 Combinatorics & Repetitions

• noneToInfinitelyTimes(String expression) Returns the expression that repeats the pattern zero to infinitely many times (*).

• oneToInfinitelyTimes(String expression) Returns the expression that repeats the pattern at least once (+).

• noneOrOneTime(String expression) Returns the expression that repeats the pattern zero or once (?).

• xTimes(String expression, int numberOfTimesToOccur) Returns the expression that repeats the pattern exactly numberOfTimesToOccur times ({n}).

• XToYTimes(String expression, int minNumberOfTimesToOccur, int maxNumberOfTimesToOccur) Returns the expression that repeats the pattern between min and max times ({min,max}).

🔤 Character Classes

• anyCharacter() Returns the expression that represents any character (.).

• anyDigit() Returns the expression that represents a digit (\d).

• noDigit() Returns the expression that represents a non-digit character (\D).

• whitespaceCharacter() Returns the expression that represents a whitespace character (\s).

• noWhitespaceCharacter() Returns the expression that represents a non-whitespace character (\S).

• wordCharacter() Returns the expression that represents a word character (\w).

• noWordCharacter() Returns the expression that represents a non-word character (\W).

• wordBoundary() Returns the expression that represents a word boundary (\b).

🔡 Character Sets

• anyLetterFromSet(...) Returns the expression that represents any character from the specified set ([...]). Supports String, List<String>, Set<Character>, Character..., and String....

• noLetterFromSet(...) Returns the expression that represents any character that is not in the specified set ([^...]). Supports the same parameters as anyLetterFromSet.

🧱 Groups & Sequences

• group(...) Returns the expression that groups the specified elements ((...)). Supports String, List<String>, Set<Character>, and String....

• charSequence(String charSequence) Returns the expression that represents the exact character sequence.

• or(String argumentA, String argumentB) Returns the expression that accepts either argumentA or argumentB (|).

🔚 Anchors & Positions

• lineEnd() Returns the expression that marks the end of a line ($).

🧱 Fluent Interface

• followedFrom(String expression) Appends the specified expression to the current pattern.

• notFollowedFrom(String expression) Adds a negative lookahead condition that ensures that the specified expression does not follow.

• getRegExString() Returns the currently constructed regular expression as a String.

📦 Predefined Patterns (RegRexCave)

• eMailRegEx Regular expression for validating email addresses.

• internationalTelephoneNumberRegEx Regular expression for validating international phone numbers.

• urlRegEx Regular expression for validating URLs.

• iPv4RegEx Regular expression for validating IPv4 addresses.

• userNameRegEx Regular expression for validating usernames.

• weakPasswordRegEx Regular expression for validating weak passwords.

• macAdressRegEx Regular expression for validating MAC addresses.

🔠 Character Sets (CharacterSet)

• upperCaseLetters Contains all uppercase letters of the alphabet.

• lowerCaseLetters Contains all lowercase letters of the alphabet.

• specialCharacters Contains a selection of special characters.

• numbers Contains the numbers 0 to 9.

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🌐 Further Documentation & Examples

For detailed instructions, usage examples, and interactive code snippets, please visit our documentation website.

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🛠️ License

This project is licensed under the MIT License. For more information, see the LICENSE file.