From: <glassfish_at_javadesktop.org>
Date: Wed, 04 Feb 2009 20:45:12 PST

Please check the contents of your jar and find if you have the com/mysql/jdbc/jdbc2/optional/MysqlDataSource.class in it. If not, then the jar was not downloaded properly.
[Message sent by forum member 'sm157516' (sm157516)]

http://forums.java.net/jive/thread.jspa?messageID=330231