This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
but type 1 driver is not suppored for web application because it require the odbc driver to installed on each client machine.
this driver is used only when you want that webapplication to run on your own machine only.
but when you require that application to run on each and every machine on web,so there is need of driver 2,3,4
but we can use type 2 but there is some problem that this is not secured enough as compare to type 3 and type 4 because if we want to change the database then we have to change the native API....
so preferred means for web-based application is type 3 and type 4..
but when it comes to performance always use type 4.
because it is a pure java driver and it communicates directly with vender's database through socket communication.