Is it possible to specify local path (ex. C:\MyAppDir) on a client into which my application is to be downloaded/deployed by the Java Web Start? If yes, how do I achive that? Does it have something to do with turning off the �sandbox� and/or JAR signing?
I would say not easily, and not without lots of fiddling.
We maintain a webstart application in our organisation that gets deployed to everyone's desktop. Our app depends on some data within files. We package these files in the jar that gets downloaded from webstart and when the application starts up, some of the initialisation code that we wrote copies those files to a local directory on C:\ (overwriting previous copies).
You might be able to get the code to copy itself (that is, the .jar file) to a local directory on startup ...
The other way to do it is to specify the java webstart cache location through the webstart application manager (file-preferences-advanced). But this means that you need to do it for all your users (for standardisation).