Linux上的Java Applet无法获得权限

I'm taking an online class and I'm occasionally getting hung-up because the class is semi windows-centric. Currently I've got a java applet in which I'm trying to play an audio clip with. I'm using Idea Intellij and I've put an audio file in the same location as the class files. I've also updated the policy file that idea uses to run the applet, but no matter what I do, it can't seem to find the audio file. I'm 75% sure it's something I've not figured out with the policy file (argh!), but I can't figure out what that is. I'll paste in a code snippet, my policy file and some output from when I try to run it. Please help - this is the second time I've been stuck due to linux-specific differences. I'm taking an online class and I'm occasionally