isbn #

Rock-solid ISBN support for Java, built on the ISO 2108 standard.

This library provides immutable value types for parsing, validating, comparing, and converting ISBN identifiers. It is suitable for use in domain models, APIs, and form handling.

Supported features:

Strongly-typed Isbn10 and Isbn13 records
Unified Isbn interface for version detection and conversion
Strict format and check digit validation
ISO 2108-conforming conversion logic

Getting Started #

Add the Dependency #

Maven

Add isbn to your pom.xml.

<dependency>
    <groupId>io.github.nutshellengineering</groupId>
    <artifactId>isbn</artifactId>
    <version>1.0.0</version>
</dependency>

Gradle Groovy

Add isbn to your build.gradle file.

dependencies {
    implementation 'io.github.nutshellengineering:isbn:1.0.0'
}

Gradle Kotlin

Add isbn to your build.gradle.kts file.

dependencies {
    implementation("io.github.nutshellengineering:isbn:1.0.0")
}

Example Usage #

Parse an ISBN #

import is.bn.Isbn;

Isbn isbn = Isbn.fromString("978-0-306-40615-7");
System.out.println(isbn.version()); // ISBN_13
System.out.println(isbn.value());   // 9780306406157

Convert ISBN versions #

import is.bn.*;

Isbn13 isbn13 = new Isbn13("9780306406157");
Optional<Isbn10> maybe10 = isbn13.toIsbn10();
maybe10.ifPresent(i10 -> System.out.println(i10.value())); // "0306406152"

Validate format at construction #

new Isbn10("0306406152");   // valid
new Isbn10("030640615X");   // throws IllegalArgumentException (invalid check digit)