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.
The FileInputStream will be looking for the file as a Real File, in the JVM's active directory (wherever that happens to be). It does not look through the classpath, and I don't think it will open a file from a JAR file either.
The resource bundle is the proper route to go here.