you can list the values in list box, by using html ptions or html ptionsCollections tag. to do this, you have to return a collection to jsp. about initializing parameters at servlet, i think you need to initialize at your action class. if so, you can override the init method.
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