Roman Numerals library for Java

Features

• Converts in both directions.
• Has strict and loose Roman numeral decoding options.
• High-performance: Can convert 100,000 numbers per second per core.
• Open Source -- AGPL license. Full source code and project build files available.
• Commercial use-friendly -- commercial license available.
• Command-line conversion tool (examples below).

Maven Setup

  <dependencies>
    <dependency>
      <groupId>com.frequal.romannumerals</groupId>
      <artifactId>roman-numerals</artifactId>
      <version>1.3</version>
    </dependency>
  </dependencies>
  <repositories>
    <repository>
      <id>frequal.com</id>
      <url>http://frequal.com/maven-repository</url>
    </repository>
  </repositories>

Download

• Binary (compiled library only): roman-numerals-1.3-bin.tar.gz
• Project (full source code and Maven build file): roman-numerals-1.3-project.tar.gz

API Examples

        converter = new Converter();

        // Convert Roman numerals to numbers
	int convertedNumber = converter.toNumber("IV"));

        // Convert numbers to Roman numerals
        String romanNumerals = converter.toRomanNumerals(1999));
	
        // Strict mode throws ParseExceptions on illegal numerals
        strictConverter = new Converter(true);
        strictConverter.toNumber("IM");

Command-line Examples

> java -jar roman-numerals-1.3.jar 3888
3888 in Roman numerals: MMMDCCCLXXXVIII
> java -jar roman-numerals-1.3.jar 6
6 in Roman numerals: VI
> java -jar roman-numerals-1.3.jar 9
9 in Roman numerals: IX
> java -jar roman-numerals-1.3.jar IX
IX as a number: 9
> java -jar roman-numerals-1.3.jar MMIV
MMIV as a number: 2004

Upcoming Features

• NumberFormat interface
• Additional strict checks