<a href="http://en.wikipedia.org/wiki/Hexadecimal">Hexadecimal</a> encoder and decoder. <p/> This class was borrowed from Apache Commons Codec SVN repository (rev. {@code 560660}) with modifications to enable Hex conversion without a full dependency on Commons Codec. We didn't want to reinvent the wheel of great work they've done, but also didn't want to force every Shiro user to depend on the commons-codec.jar <p/> As per the Apache 2.0 license, the original copyright notice and all author and copyright information have remained in tact.