Java: it works or it doesn't. Since it's compiled object oriented code, if you're running a java applet or something, chances are, it's pretty safe. Especially considering it's server side and has much greater potential for lockdown (on their side) whereas Javascript is client-side driven and is easily broken.
Java applets are downloaded to the clients machine and run locally by the jvm of the browser or an external jvm. The downloaded classes are not compiled files, they are byte code which is then compiled and run by the java virtual machine. Java applets by nature are not permitted by the jvm to perform i/o on the client machine (unless it is signed of course). It is java servlets that are run on the server's side.

What is the problem with having a machine connected directly to the internet. Do you honestly think that your cheap made in korea linksys 'router' is anymore effective than IPchains?