An
applet can only communicate with the host from which it is loaded. Hence it cannot access the System DSN on your machine. I dont know about the J-Developer kit. However if u are using jdk then u will have to modify the
java policy file to grant access, then it will work using appletviewer, but not on your browser. to grant access via browser u have to sign the applet or use pure java drivers which can be sent to the client machine via jar files.
Hope this helps.