shinetimes / jnanoid

A unique string ID generator for Java.

JNanoId

A unique string ID generator for Java.

Secure

JNanoID uses Java’s SecureRandom to generate cryptographically strong random IDs with a proper distribution of characters.

Compact

JNanoID generates compact IDs with just 21 characters. By using a larger alphabet than UUID, JNanoID can generate a greater number of unique IDs, when compared to UUID, with fewer characters (21 versus 36).

URL-Friendly

JNanoID uses URL-friendly characters (A-Za-z0-9_-). Perfect for unique identifiers in web applications.

Customizable

JNanoID is fully customizable. All default options may be overridden. Supply your own Random Number Generator, alphabet, or size.

Tested

JNanoID is thoroughly tested with JUnit.

Latest Release

The most recent release is JNanoId 2.0.0.

Maven

<dependency>
  <groupId>com.aventrix.jnanoid</groupId>
  <artifactId>jnanoid</artifactId>
  <version>2.0.0</version>
</dependency>

Gradle

compile 'com.aventrix.jnanoid:jnanoid:2.0.0'

Usage

JNanoId provides one easy-to-use utility class (NanoIdUtils) with two methods to generate IDs.

Standard IDs - randomNanoId()

The default method creates secure, url-friendly, unique ids. It uses a url-friendly alphabet (A-Za-z0-9_-), a secure random number generator, and generates a unique ID with 21 characters.

String id = NanoIdUtils.randomNanoId(); // "ku-qLNv1wDmIS5_EcT3j7"

Custom IDs - NanoIdUtils.randomNanoId(random, alphabet, size);

An additional method allows you to generate custom IDs by specifying your own random number generator, alphabet, or size.

// Use a faster, but non-secure, random generator
Random random = new Random();

// Use a custom alphabet containing only a, b, and c
char[] alphabet = {'a','b','c'};

// Make IDs 10 characters long
int size = 10;

String id = NanoIdUtils.randomNanoId(random, alphabet, 10); // "babbcaabcb"

Copyright and license

Code copyright 2017 The JNanoID Authors, Aventrix LLC, and Andrey Sitnik. Code released under the MIT License.

Based on the original NanoId for JavaScript by Andrey Sitnik.

Other Programming Languages

• C#
• Clojure and ClojureScript
• Crystal
• Dart
• Go
• Elixir
• Haskell
• JavaScript
• Nim
• PHP
• Python
• Ruby
• Rust
• Swift

Also, a CLI tool is available to generate IDs from the command line.