This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
To get unlimited access to the disk, you will need to set the following tag in the jnlp file:
For this to work, you will also need to sign all the jar files using "jarsigner".
If you don't have a signed jar, you might need to make use of the "JNLP API" to access the file system. (I say might because I'm not sure. You might be able to read a file without a signed jar. I always sign mine.)
subject: Can an application read the resources outside of its own directory structure?