You could add a main method so that the applet works as an application as well. Then you can override the "getParameter" method so that it either calls applet.getParameter (if run as an applet), or (e.g.) reads the parameters from a property file (if run as an application).
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com