Can someone advice on the feasability of connecting an existing Java application (deployed via Web Start) to a Portlet?
Currently I'm using a JDBC connection to retrieve data directly from an Oracle DB
but I have no idea about portlet
can you help me?
The portlet would query the database just like any other J2EE UI would. If you're using straight JDBC, you just configure a Data Source on your application server, write code to do a JNDI lookup for that Data Source, and grab your connections from it. ;)