How can I get all the available database drivers?

The basic problem is that, the getDrivers() method in DriverManager class gives you list of all the drivers registerd with it and not all those are available on machine. Unless and until any driver is not initialized / registered with DriverManager, by means of registerDriver() of Driver interface, you will not get that driver availabe to you. Can anybody help me in this regard, so that I can get all the available driver list?

V. V. Joshi.