I am not sure I follow your question.
By configuring your connection pool and datasource in the console your jdbc information IS specified in an xml file, config.xml.
Simple depiction of how to get the datasource using the JNDI name (try/catch code not included):
Context ctx = new InitialContext();
DataSource ds = (javax.sql.DataSource) ctx.lookup("connpoll");
If you are trying to get the DataSource from the client-side, then see
Obtaining a Client Connection Using a DataSource.
[ May 18, 2005: Message edited by: Carol Enderlin ]