The Apache Commons Codec package contains simple encoder and decoders for various formats such as Base64 and Hexadecimal. In addition to these widely used encoders and decoders, the codec package also maintains a collection of phonetic encoding utilities.
A Java class providing very fast Base64 encoding and decoding in the form of convenience methods and input/output streams.
MiGBase64 is a very fast and small Base64 Codec written in Java
Base64 codec that depends on nothing but core java. compiled to lang level 1.5.
Jbundle Thin Base Util Base64 Base64 Code