The JGlobus MyProxy client provides a full-featured Java client API for MyProxy, in contrast to the simple MyProxyLogon Java client API that supports only retrieving credentials from MyProxy.
MyProxy for JGlobus 2.0
JGlobus 2.0, including the MyProxy client, is now available at https://github.com/jglobus/JGlobus.
MyProxy for JGlobus 1.x
Older versions of the JGlobus MyProxy client are available as part of the Java CoG.
See org.globus.myproxy Javadocs for documentation of the JGlobus MyProxy API.