Base62 Library

This is a small Java library for encoding and decoding data in base-62 format.

It is mainly intended for encoding UUIDs in a way that is both compact and works well in URLs. In contrast to base-64, it doesn’t require any non-alphanumeric characters.

The 62 digits of the Base-62 system are represented by the 10 characters for decimal digits (0 …​ 9), 26 uppercase alphabetic characters (A …​ Z), and 26 lowercase alphabetic characters (a …​ z).

The base-62 encoding requires 11 digits (characters) for a 64-bit long, and 22 characters for a UUID.

The library only supports encoding long and UUID values, and decoding strings whose length is a multiple of 11.

Usage

The library is available through Maven Central.

pom.xml

<dependency>
  <groupId>org.unbroken-dome.base62</groupId>
  <artifactId>base62</artifactId>
  <version>1.1.0</version>
</dependency>

The interface of this library are the static methods of the Base62 class.

// Encode a long or an array of longs
String encoded = Base62.encode(-4468979493829131317L);
//    --> "aK7yM6vAKKD"

// Decode a long from base-62
long[] decoded = Base62.decode("aK7yM6vAKKD");
//    --> [ -4468979493829131317L ]

// Encode a UUID
String encoded = Base62.encodeUUID( UUID.fromString("977d66bd-56af-4ad9-a0f7-b0dbe51e25fc") );
//    --> "dyIujXEusfXd9r2hZoE6zM"

// Decode a UUID
UUID decoded = Base62.decodeUUID("dyIujXEusfXd9r2hZoE6zM");
//    --> UUID 977d66bd-56af-4ad9-a0f7-b0dbe51e25fc