I am new to Java programming so forgive me if these questions seem out of

1)Ok, so I have been programming using Delphi and VB etc for various clients,
why might I want to develop a GUI client application (not an applet) using

2)If my application is to be installed on a machine that only has DOS (say)
how can I access a database such as Oracle, Sybase, SQLBase, Dbase etc.

3) If I cannot access the above databases, which ones can I access under